IMS 2020
2020 Technical Conferences List
Note if you see:
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And if you see a Calendar (📅) is a link to an event schedule page.
TMA1: Understanding Oscillator Phase Noise and Locking
In this lecture, we will discuss the nature and properties of oscillators and the general behavior of the phase noise.
Feng Feng - Carleton Univ.
Electromagnetic (EM)-based yield estimation plays an important role in microwave design due to the presence of uncertainties in manufacturing processes.
IW17ABC : Multi-Channel mmWave EW Receiver Workshop
an overview of other multichannel platforms available from Keysight
IW24AB : Understanding 5G System-Level Evaluation
Early deployments of 5G are rapidly under way. 5G features include enhanced mobile broadband, massive machine type communication, ultra-reliable and low latency connection, Vehicle-2X, and more. What does this mean to filter, amplifier, and antenna designers? This presentation distills the essentials of 3GPP NR standard specifications and demonstrates how Visual System Simulator (VSS) software within the NI AWR Design Environment platform can be configured for various scenarios envisioned for 5G.
📺 Th3C-2: Measurement-Based Performance Investigation of a Hybrid MIMO-Frequency Scanning Radar
Example: firefighters helments going into an environment where pathways or escape routes may not be visible because of smoke or fire. Limited amount of space to mount components.
📺 WEMA41 : How Material Properties and Fabrication can Impact RF Filter Performance
This presentation will show how normal variation of certain material properties can have an effect on RF performance of different types of PCB based filters. The same analogy will be done with PCB fabrication processing variables showing how they can impact the RF performance of a PCB based filter.
📺 IW26A : Understanding 5G New Radio (NR) Release 15/16 Standards
Learn about the technology and challenges associated with the implementation of the 5G NR Release 15 standard and uncover new details about its numerology, frame structure, and waveforms.
📺 Th1F-4 : Scalable, Deployable, Flexible Phased Array Sheets
Large aperture flexible and deployable phased arrays will enable active RF fabric and deployable array structures for terrestrial and space applications. The flexible phased array design paradigm is enabled by small, multi-function radio frequency integrated circuits and low mass radiators, which avoid conventional dielectric materials. This paper presents a 256 element, 30 cm × 30 cm flexible phased array, operating at 10 GHz and focusing 0.8 W at 2 m distance. A novel beam-focusing algorithm is used to demonstrate 2-D beam-steering and deformation correction capabilities of the flexible phased array.
📺 IW4A : Best Practices for Efficient EM Simulation
Designers of today’s complex, multi-featured communications products require accurate and fast EM simulation to deliver cost-effective, high performance products to market.The AXIEM EM simulator delivers the accuracy, capacity, and speed designers need to characterize and optimize passive components on RF PCBs, modules, LTCCs, MMICs, RFICs, and antennas. This presentation discusses 10 best practices for using the AXIEM simulator that will help designers effectively and efficiently use the software to overcome the most commonly encountered issues when running EM simulations. The best practices address four main design areas: ports, EM environment, meshing, and simulation.
A self-mixing receiver support distributed frequency locking in coherent distributed antenna arrays is presented. Coherent distributed antenna arrays require accurate phase, frequency, and time alignment. However, each node in the distributed array generates its frequency using independent oscillators, and thus without appropriate frequency synchronization the emitted signals will not appropriately cohere. In this paper, we present a one-way frequency transfer approach that uses a self-mixing circuit architecture in a master-slave synchronization architecture. The master node transmits a multi-tone signal that consists of two tones separated by a 10 MHz frequency reference. The self-mixing circuit receives and demodulates this signal by splitting it and then passing it to the radio-frequency (RF) and local oscillator (LO) terminals of a mixer. The resulting signal is filtered to retain only the 10 MHz modulation, which is used to discipline the oscillator on the slave node. We present experimental results using software-defined radio, showing wireless synchronization via a cabled distributed beamforming experiment at 1.5 GHz.
In this paper, a scalable, fully digital adjustable, bistatic 60 GHz MIMO six-port transceiver is presented. The circuit features four independent transmitters and four six-port receivers on a single chip. The reference clock frequency of 15 GHz is buffered and multiplied up to 60 GHz. The reference clock is also amplified and feed to an output port of the chip to render possible cascading multiple chips for massive MIMO applications. The receivers each include a VGA to set the reference power level, a LNA for amplification of the weak antenna signal and the six-port structure with three broadside linecoupler, a wilkinson-divider and four power detectors. The transmitters each include a switched-line phase shifter and a power amplifier. The chip has a size of 4mm × 3.1mm and a power consumption of 960mW from a 3.3V power supply. A minimum input power of -22dBm is needed at the input clock. The transmitters deliver a maximum output power of 9.1dBm at 60 GHz. The phase is adjustable in a range from 0° to 325.4°. The successful measurement results indicate, that the MIMO six-port transceiver is well suited for radar applications.
📺 Th2G-3 : A Power Efficient BiCMOS Ka-Band Transmitter Front-End for SATCOM Phased-Arrays
A high efficiency 27–30 GHz 130nm BiCMOS transmitter front-end MMIC for mobile satellite communication phased-array is presented. The implemented chip consists of a gain control block with 15 dB gain variation, a 400 degree phase shifter and a high efficiency two stage power amplifier. The chip has a measured transducer gain of 23 dB and power consumption of 45 mW at P1dB of 10.8 dBm. The power added efficiency (PAE) of 26.7% is measured for the entire channel at P1dB. An error vector magnitude (EVM) of -29 dB at Pout,avg of 5.7 dBm and PAEavg of 12% is measured for a 400 MHz bandwidth 64-QAM (1.8 Gbps) modulated signal. The overall size of the chip is 2.1×0.8 mm².
The trend towards smaller form factor MIMO radar systems is enabled by modern SiGe BiCMOS technologies in which more functionality can be integrated into MMICs, including digital control logic beside analog low- and high-frequency circuits for signal generation, transmitting, receiving and also modulating waveforms, like in this work. Industrial measurement, automotive or security applications demand small imaging radar systems. For this purpose, a compact K-Band MIMO radar system with code-division multiplex (CDMA)-modulation for TX-separation was developed. It is based on an ultra-wideband (UWB) SiGe chipset suitable for MIMO operation which provides MMICs for signal generation of over 40 GHz bandwidth below 60 GHz, a 4-channel phase-shifting transmitter that operates between 1–30GHz and a 4-channel receiver that operates between 1–65 GHz. Following the description of the system architecture, the SiGe MIMO chipset is explained, before 3D MIMO measurement results are presented at the end.
A novel method for the localization and autonomous tracking of bees within their natural habitat is presented herein. Mechanical energy produced from bee motion is captured and converted to power a miniature bee wearable transmitter weighing ~30mg. A compact phased array antenna affords angle of arrival (AOA) estimation and bee localization through a received signal strength indicator approach (RSSI). The AOA estimate is autonomously fed into the control system of a drone allowing for continuous position updates. The experimental results show proof of concept towards autonomous tracking of tagged bees.
📺 Th3C-4 : Harmonic Micro-Doppler Detection Using Passive RF Tags and Pulsed Microwave Harmonic Radar
A pulsed radar system and harmonic tag design for the detection of harmonic micro-Doppler signatures in cluttered environments is presented. While radio-frequency identification research has focused heavily on detection, this work uniquely focuses on measuring the tag motion based on harmonic frequency shifts. The tag retransmits the incident signal at a harmonic frequency, enabling the harmonic radar receiver to detect the frequency shift without the presence of clutter, which is confined to the fundamental frequency band. A new harmonic tag based on a wire dipole, diode, and wire-based reactive components is presented, which operates at 2.51 and 5.02 GHz frequencies. A pulsed harmonic radar is offered that is able to achieve measurements at greater distance than continuous-wave systems. We present time-frequency responses of the tag movement at a distance of 1 m to demonstrate the ability to detect object motion based on the frequency shift of the harmonic micro-Doppler response.
Fields of application like industrial measurement, security, and material characterization with harsh demands for high spatial resolution require FMCW radar systems with high absolute bandwidth. Hereby, close adjacent targets can be distinguished from each other. Usually those systems are designed at very high frequencies around 100GHz and above because here, sensors with high bandwidth can be designed with less effort but signal handling, antenna design and high output power is more difficult and harder to achieve at those frequencies. In this work, a modern SiGe BiCMOS process was used to develop an ultra-wideband (UWB) bistatic FMCW radar MMIC with over 40 GHz continuous bandwidth below 60 GHz. This MMIC is the key component of the presented ultra-wideband FMCW radar system. The high bandwidth is generated by down-converting two high-frequency VCOs at around 100GHz but merely the down-converted signal below 60 GHz of both VCOs which is easier to handle leaves the MMIC. The output signal provides a frequency range which corresponds to the sum of the bandwidths of both VCOs. This leads to a radar system that achieves ultra-wide continuous bandwidth at moderate frequencies for high spatial
For the first time, we propose a combination of coupled defected ground structure (DGS) resonators for wireless power transfer and coupled Figure-8 inductors for information transfer. This combination allows the realization of a simultaneous compact wireless power and information transfer (WPIT). Each set of the DGS resonators and the Figure-8 inductors are located on the same plane. However, they show negligible coupling due to the coupling cancellation mechanism of the Figure-8 inductors. Hence, high isolation can be achieved between the power and information channels. A prototype is fabricated for operation at 50 MHz and 100 MHz. The overall area of the TX/RX is 30 mm × 30 mm and are separated by 14 mm. The measured efficiencies are 78% and 76% at 50 MHz and 100 MHz, respectively, and the isolation is more than 34 dB.
📺 Th2E-2 : Conductive Coupler for Wireless Power Transfer Under Seawater
This paper presents a coupler consisting of two pairs of parallel-plate electrodes for wireless power transfer (WPT) under seawater. The paper clarifies two points. One is the operational principle of our conductive coupler using a simplified equivalent circuit. The crucial parameters for the design are based on a theoretical equation to obtain maximum available efficiency ηmax. The other is to clarify the power transfer efficiency η via a demonstration of the WPT. A design method using an electromagnetic (EM) simulation is introduced and the prototype is manufactured. Results showed that ηmax of 79% at 2 MHz from the measured results could be achieved. Furthermore, η of about 50% at 6.78 MHz was maintained at around an input power of 275 W.
📺 [Th2E-3 : The K-Band Communication Transmitter/Receiver Powered by the C-Band HySIC Energy Harvester with Multi-Sensors]https://cdn.filestackcontent.com/XiWoyoRATxemPW7OpmYa)
Japan Aerospace eXploration Agency
The 24 GHz communication system was demonstrated with wireless multi-sensors by wirelessly powering at 5.8 GHz. The wireless sensors for health monitoring in a space vehicle work as the sensors of temperature, humidity, acceleration, illuminance, battery voltage and sound in this study. Under output power of 30W from a GaN transmitter, a GaAs rectifier of energy harvester was operated with more than 80% RF-DC conversion efficiency.
In this paper, we demonstrate a fabric-integrated, near-zone wireless power transfer system, which uses a newly developed misalignment resilient antenna element for inductive power transfer in wearable applications. The antenna consists of an anchor-shaped geometry, which uses a combination of electric and magnetic field couplings in the near field to achieve high power transfer efficiency (PTE) of 85% even under lateral misalignment. Improvement in PTE for lateral and angular misalignment cases is demonstrated which facilitates the near-zone power transfer for practical usecases. For fabric integration, the proposed antenna and rectifier system were fabricated on a textile substrate by using conductive thread embroidery. We report the PTE of the developed antennas variation with different types of misalignment cases. For lateral misalignment, the proposed antenna exhibited an average PTE of 85% for lateral movements of 1 to 10 cm. Furthermore, the antennas exhibited an average PTE of 70% for elevation and 60% for azimuthal misalignment cases. These results are compared with circular loop resonator illustrating the improvements in the PTE. Using this antenna element, power harvesting system and its resilience to misalignment are also demonstrated.
📺 Th2E-5 : A 3D Rectenna with All-Polarization and Omnidirectional Capacity for IoT Applications
A 3D rectenna with all-polarized and omnidirectional capacity is presented in this paper. The proposed rectenna is composed of six dual-linear polarized (DLP) rectennas, in a hexahedron. Each DLP cell is composed of a DLP antenna, a 90° hybrid, and a modified rectifier. The 90° hybrid and modified rectifier are employed to reallocate received powers between two ports of DLP antenna, and the topology can maintain high RF-to-DC power conversion efficiency when the polarization of incident wave is uncertain or varying. The proposed 3D rectenna can harvest RF power all round efficiently. With a measured power density of 355 µW/cm², the output dc power maintains above 1.2 mW when the tile angle varies from 0° to 360° perpendicular to the surface of rectenna, and the maximum dc power is 2.8 mW.
📺 Th2E-6 : RF Energy On-Demand for Automotive Applications
This work proposes the design of a Wireless Power Transfer (WPT) system in the 2.4 GHz band, suitable for remotely energizing low-power wireless sensors located in highly complex environments from the electromagnetic propagation point of view. This is the case of many industrial scenarios such as industrial machineries or automotive engines, to enable remote monitoring, predictive maintenance and components diagnosis. A co-designing method was used to obtain a system of independent RF sources embedded in the complex environment, with the aim of being at the same time miniaturized for easy integration into the environment, and of having the ability for providing energy wirelessly in a pervasive way. The validation of the project shows that even wireless sensors located in critical and NLOS (Non-line-of-sight) positions, placed in key points of the engine compartment and in contact with parts that need to be monitored, can be successfully energized by the proposed approach. This enables battery-less sensors to be powered and to simultaneously communicate with a gateway in order to monitor vital engine parameters. A communication among the gateway and a number of battery-less sensor nodes is demonstrated exploiting low-power LoRa (Long Range) nodes working in the same frequency band of the RF powering system.
📺 Th2D-1 : RF Systems on Antenna (SoA): A Novel Integration Approach Enabled by Additive Manufacturing
This paper introduces for the first time, the novel concept of the system-on-antenna (SoA) which incorporates the ideas behind system-on-chip (SoC), system-on-package (SoP) and on-chip/package antennas, to create a new generation of fully integrated RF modules. This concept is only achievable using additive manufacturing, which is a rapid, on-demand and low cost fabrication technology. Instead of wasting valuable wafer or packaging area to create antennas, a novel method using 3D and inkjet-printing was utilized to embed a Ku-band radar module into a 10dBi horn antenna. The uniqueness of this system, lies in the fact that SoA topologies can be easily fabricated using additive manufacturing, but unfeasible utilizing traditional fabrication techniques. This design methodology allows antennas to be compactly integrated within RF modules and sets the foundation for on-demand customizable SoA modules for a multitude of applications ranging from 5G+ and IoT to implanted medical and wearable applications.
📺 Th2D-2 : Wireless 3D Vertical Interconnect with Power Splitting Capability
Power generation reduces at millimeter wave frequencies for emerging system applications, such as 5G. Thus, loss presents many design challenges for complex integrated system design. This paper proposes to alleviate loss associated with vertical interconnects used in such systems. A wireless equal split 3D vertical power divider that offers very low loss is presented. Two near field beams, produced by one source element and a novel frequency selective surface (FSS), are detected by individual receive elements of the same type. This design is scalable, modeled at 13.5GHz and 60GHz. A 13.5GHz scale model is demonstrated for validation. Simulated insertion loss coefficient at 13.5GHz is 3.24dB, with bandwidth of 5.5%. Modeled and measured results are in good agreement.
This paper presents a first-of-its-kind fully 3D-printed mm-wave reflectarray with one-shot deployability. It consists of an array of kirigami-inspired flat-foldable dielectric-based unit cells featuring an unprecedented reduction in volume as compared to its conventional counterparts. The prototype is fabricated with high-resolution stereolithography 3D printing together with flexible photosensitive resin. The outcome of this work demonstrates a low-cost, high-performance dielectric reflectarray design that can be folded to 1/3 of the full-scale volume which can be used for outer-space, 5G and various other terrestrial applications.
In this paper, we propose an assessment up to 325 GHz of Micro Laser Sintering (MLS) metal 3D-Printing technology in order to achieve lightweight and cost-effective millimeter wave (mmW) passive function. We first designed and manufactured a bended WR5 waveguide in order to assess achievable roughness and insertion loss. In a second step, an existing 240 GHz choke horn antenna design, previously manufactured using metal coated Stereo Lithography Apparatus (SLA) and Selective Laser Melting (SLM) technologies, has been prototyped using MLS. Measured performances of the MLS antenna prototype have been benchmarked with SLA and DMLS ones. Achieved performances are promising since without any post processing MLS compete up to 325 GHz with metal coated SLA technology while it enables a metallic part manufactured in a single piece.
A self-mixing receiver support distributed frequency locking in coherent distributed antenna arrays is presented. Coherent distributed antenna arrays require accurate phase, frequency, and time alignment. However, each node in the distributed array generates its frequency using independent oscillators, and thus without appropriate frequency synchronization the emitted signals will not appropriately cohere. In this paper, we present a one-way frequency transfer approach that uses a self-mixing circuit architecture in a master-slave synchronization architecture. The master node transmits a multi-tone signal that consists of two tones separated by a 10 MHz frequency reference. The self-mixing circuit receives and demodulates this signal by splitting it and then passing it to the radio-frequency (RF) and local oscillator (LO) terminals of a mixer. The resulting signal is filtered to retain only the 10 MHz modulation, which is used to discipline the oscillator on the slave node. We present experimental results using software-defined radio, showing wireless synchronization via a cabled distributed beamforming experiment at 1.5 GHz.
We present millimeter-wave imagery at 13.7 frames-per-second (fps) using a digital 16-element interferometric antenna array operating at 37 GHz. The scene is illuminated incoherently using three low-cost noise transmitters, mimicking the properties of thermal radiation. The array is based on commercial components and 3D-printed horn antennas. The system architecture is presented, along with the signal processing algorithm, and real-time imaging results.
This paper presents a novel radar technology for precise position measurements (e.g. crane positioning) between two cooperating radar units that is especially suited for use in harsh industrial environments. The concept uses the novel coherent full-duplex double-sided two-way ranging (CFDDS-TWR) FMCW secondary radar concept and combines a beat frequency estimation and a coherent phase tracking even though the two cooperating radar units work incoherently. The novel CFDDS-TWR and phase tracking method allows for an efficient suppression of multipath distortions and enables a displacement measurement with a standard deviation of approx. 13 µm and improves the overall ranging accuracy compared to existing bistatic secondary radar approaches dramatically.
📺 Th2C-4 : Phase Recovery in Sensor Networks Based on Incoherent Repeater Elements
A coherent sensor network without hardware link between the network nodes can be set up based on a single MIMO-radar and several incoherent repeater elements spatially distributed. The repeater sends back the radar signal on the same way it was impinging onto the repeater. All repeater elements have an integrated double-sideband modulator, which allows to separate the signals of different repeater elements at the radar. For angle estimation, the phases of the signals of the repeater elements are crucial, but due to an unknown initial phase of the modulation signal, they cannot be determined directly. Thus, a reconstruction of the modulation phase is necessary for network-based coherent angle estimation. In this paper, a concept for phase reconstruction in such type of networks is proposed, exploiting both sidebands of the modulated signal of the repeater elements.
In this paper, a novel method for tracking targets using OFDM radar with an integrated communication system (RadCom) for automotive applications is presented. OFDM-based radar schemes are promising candidates for future intelligent transportation networks. However, due to system resolution limitations, improvements in estimation and tracking of targets are required. Correct and accurate object tracking is a critical aspect of advanced driver assistance systems. The proposed method takes advantage of the dual functionality of RadCom systems through an information fusion approach that combines the radar signal reflected by the targets with received communication signals. The main idea is to explore cooperation between vehicles to improve safety and accuracy during tracking. Tracking results of laboratory measurements at 24 GHz and simulation results in a multi-target environment are presented.
This paper presents a W-band rectenna unit, which incorporates an optimized CMOS switching rectifier and a print tapered slot antenna. Based on the analysis of the operation principle of the switching rectifier, this paper proposes an optimized structure of the switching rectifier and the body-diode effect (BDE) to improve reliability and power conversion efficiency (PCE). Besides, a high-gain W-band antipodal linearly tapered slot antenna (ALTSA) is implemented on PCB to improve the overall efficiency. The switching rectifier achieves a peak PCE of 45.8% at 94 GHz with improved reliability. The overall PCE of the rectenna unit up to 25% is achieved with 5.6 mW output dc power under 90 mW/cm² incident power density. The proposed rectifier and rectenna achieve the highest PCE among recently reported W-band rectifiers and rectennas with different technologies.
The reverse leakage current in the rectifier is a key challenge in the design of RF energy harvesting (RF-EH) systems, especially in harvesting modulated RF signals from WLAN band. In this paper, we propose a dual-band energy harvesting system operating at GSM-900 (900 MHz) and WLAN (2.4 GHz) bands. To harvest the RF energy from the WLAN band more efficiently, an event-triggered 1:2 parallel-series switched-capacitor (SC) converter is proposed to reduce the reverse leakage current. Meanwhile, this SC converter can provide an output voltage bootstrapping function while maintaining an ultra-low-power consumption down to 28 nW by asynchronous control. The power management unit (PMU) with the rectifier is fully integrated in a CMOS 130-nm process. Measurement results have shown the PMU can boost up the output voltage by 1.73× with an input voltage as low as 0.2 V. When harvesting the modulated waveform, the RF-EH system output ripple is decreased by 6×, and reverse leakage current reduction is over 2500× compared to the direct connection condition.
In this paper, a microwave rectifier based on a Schottky diode, a short-ended transmission line, and a microstrip coupled transmission line is proposed, resulting in a very simple and compact structure if compared with other similar designs. Furthermore, the proposed microwave rectifier is shown to be effective for achieving good impedance matching and, at the same time, it provides outstanding RF-to-DC conversion efficiency for input power as low as 1 mW. In particular the manufactured prototype exhibits a measured microwave-to-DC conversion efficiency of 62% which is a remarkable result if compared with state-of-the-art designs based on the same Avago HSMS285C or similar Schottky diodes.
This work presents a high-efficiency, high-sensitivity, compact flexible rectenna based on a high-impedance folded dipole antenna, for sub-1 GHz license-free applications. A voltage-doubler rectifier is studied parametrically, using Electromagnetic-Harmonic Balance co-simulation, to extract the optimal load and source impedances for maximum power conversion efficiency (PCE), using an iterative source and load tuning approach. The proposed antenna is then studied parametrically and designed to directly conjugate the rectifier’s impedance eliminating the matching network and its associated losses. The integrated rectenna is ultra-compact (area=0.0122λ^20) and is fabricated on a 25 µm-thick flexible low-cost polyimide substrate. The proposed rectenna achieves a remarkable PCE of 43% and 83% at -20 and -4 dBm, respectively. Furthermore, a 1-V DC output is achieved across a 20kΩ load (optimal impedance) from -9 dBm input. The rectenna demonstrates a -3 dB (50% relative PCE) fractional-bandwidth of 7.9% (813–880 MHz), covering the 868 MHz license-free band.
In this paper, the 920 MHz band rectenna with the high impedance folded dipole antenna on the artificial magnetic conductor substrate is described for high sensitive operation and placement on metal plates. With the antenna architecture, antenna impedance of 16 kΩ can be obtained, and this can make high efficient operation with the 40 nm SOI-CMOS rectifier IC. The developed rectenna achieves rectification efficiency of 58% at the input power of -30 dBm. Furthermore, the rectenna on the metal plate achieves rectification efficiency of 72%. Above values are top performances in 920 MHz band rectennas.
📺 Th1C-1 : A Fast-Chirp MIMO Radar System Using Beat Frequency FDMA with Single-Sideband Modulation
In this paper, we investigate the feasibility of using a fast-chirp frequency-modulated continuous-wave radar system in order to realize frequency-division multiple-access multiple-input multiple-output. The frequency shifting is implemented by single-sideband modulation for unambiguous range enhancement. Furthermore, we apply a binary mask to separate transmit signals at the receivers instead of using a bandpass filter. Measurements accomplished using a prototype radar system with 3 transmit antennas and 4 receive antennas demonstrate the proposed approach.
In this paper a thorough system analysis to evaluate the overall imaging performance of millimeter wave radar systems is presented. All relevant noise influences and their influence on the system performance are considered. A comparison of two imaging radar systems at 160GHz with different hardware architectures is discussed, one of which is based on monolithic microwave integrated circuits (MMICs) optimized for low phase noise. Radar measurements are performed to evaluate the achievable imaging performance with both realized radar demonstrators. It is shown that the optimization of the phase noise of a single MMIC is not necessarily advantageous when used for multi-channel radar systems.
📺 Th1C-3 : Millimeter-Wave Interferometric Radar for Speed-Over-Ground Estimation
In this work we present a V-band interferometric millimeter-wave continuous-wave (CW) radar operating at 42.875 GHz for vehicle speed-over-ground estimation. The system points normal to the road-surface providing a constant target range and radar cross-section (RCS), and thus a deterministic signal-to-noise ratio (SNR) compared to outward-looking systems. Interferometric processing is performed by correlating the received signal responses from a pair of antennas separated by a baseline of 8λ. The system is designed with three independent phase-quadrature receive channels to allow for a pair of orthogonal baselines. On-vehicle measurements were performed for a single baseline parallel to the direction of travel and velocity was estimated directly from the received radar spectrum. The estimator consists of a fully-connected feedforward neural network (NN) with smoothing which achieved a root-mean-squared error (RMSE) of 0.204(m)/(s)] on a 2-minute data capture.
📺 Th1C-4 : Root-MUSIC Based Power Estimation Method with Super-Resolution FMCW Radar
This paper proposes a method for estimating the reflection power with high accuracy while estimating the target position beyond the Rayleigh limit with FMCW radar. Although eigenvalue decomposition methods such as MUSIC have been studied to achieve high resolution in localization, their estimated pseudo power spectrum is not related to the actual signal intensity. In this method, root-MUSIC is used to obtain the multiple frequencies included in the received signal, and then the least squares method is sequentially applied to calculate the complex amplitude corresponding to each obtained frequency. The reflection intensity of each frequency can be calculated as the power of the absolute value of its complex amplitude. An experiment using different size scatters is conducted and shows that the proposed method can estimate the power of the signal from each target while estimating the distance beyond the Rayleigh limit.
This paper proposes a new approach to Direction-of-Arrival Estimation using Artificial Neural Networks. It is capable of estimating both, model-order and azimuth DoA in a single step. In a hybrid approach, we train on synthetic data generated from a signal model and validate on data obtained through a measurement setup. We show a proof-of-concept for the hybrid approach, validated with measurement data. Advances on the exactness of the signal model enable the trained ANN to handle real-world data out-of-the-box. Our findings indicate super-resolution performance and the capability of estimating even high model-orders while significantly reducing computation time.
This paper presents a planar, 1024-element, Ku-band SATCOM transmit phased array. It can synthesize any polarization, such as linear, rotated-linear, left-hand and right-hand circular polarizations since it is constructed using dual-polarized antennas and 8-channel silicon beamformers. The 1024-element array is assembled using four 256-element arrays, and is scalable in a 2×N fashion. An antenna spacing of λ/2 at 14.4 GHz is used in an equilateral triangular grid, and results in ±70° beam steering in all planes. Measurements show that the 1024-element array has a 3-dB beamwidth of 3.2° and 3.7° in the principal planes with a cross-polarization (X-pol) level of -34 dB at broadside, and with 42.5 and 43.5dBW EIRP at P1dB and Psat, respectively, per polarization. According to the authors’ knowledge, this work presents a state-of-the-art Ku-band transmit phased-array solution with high EIRP for Ku-band SATCOM mobile terminals.
📺 We3F-4 : A Scalable 256-Element E-Band Phased-Array Transceiver for Broadband Communications
This paper presents an E-band communication link using a 256-element phased-array. The design is based on 8-element sub-arrays, using transmit/receive beamformer chips employing a 6-bit phase shifter fabricated in a SiGe BiCMOS process. Antennas were implemented on a 19-layer LTCC substrate. A 20 meter communication link was realized using a 5G NR, 400 MHz bandwidth, OFDM with 120 kHz sub-carrier spacing.
📺 We3F-3 : Affordable, Multi-Function Flight-Worthy Airborne Phased-Array Sensor
A dual-beam, dual-polarized wide-beam scanning phased array is designed, fabricated, assembled and tested at Ku- band for airborne sensing and communication applications. Compared with a prior proof-of-concept COTS-based phased-array, this demonstration uses custom MMICs to double the number of beams, double the transmit power output, increase the grating-lobe free beam scanning range from 50° to 60° and add additional array functionality. Custom MMICs and ASICs add more phase- and amplitude-bits and more than 20 dB in amplification significantly stressing transition matching, grounding and cavity mode suppression requirements. A custom seal ring over the entire array helps to choke-out cavity modes and increases isolation to ensure electronic stability across the aperture. The metallic seal ring also removes heat away from the electronics. A 120° dual-beam scanning volume on receive and switchable beams on transmit has been demonstrated and used on a wide range of sensor and communication applications.
This paper presents studies on the self-interference level of a 28-GHz full-duplex phased-array system. The full-duplex system consists of two 64-element phased-arrays and a 28-GHz canceller. The phased-arrays are designed with 2×2 beamformer chips, and the arrays are used as a transmitter and a receiver with a cross-polarization set-up. The 28-GHz canceller is also based on the same 2×2 beamformer chip with multiple-delay taps. The full duplex front-end with a canceller results in 57-dB isolation between the transmitting and receiving arrays at 28.5–29.5 GHz without saturating any LNAs. The system requires only 16-dB additional digital cancellation to bring the self-interference down to the receiver noise floor of 1-GHz bandwidth while the transmit EIRP is maintained at 41 dBm.
This paper presents a scalable switchable dual-polarized 256-element Ka-band SATCOM transmit (TX) phased-array with embedded driver. The phased-array is based on 64 SiGe 8-channel TX beamformer chips and uses low-cost printed circuit board (PCB) and surface mount technology (SMT). The phased-array can transmit clockwise and counter-clockwise polarization which is suitable for Ka-band SATCOM. It demonstrates a measured 6.8° 3-dB beamwidth, +32 dBW (+62 dBm) EIRP on axis, greater than 25 dB cross-polar discrimination (XPD) and the ability to scan to ±70° in all planes. The scalable nature allows for economical construction of larger phased-array without grating lobes. A compact size of 11.7 × 7.5 cm² makes it suitable for Ka-band SATCOM portable terminals.
📺 We3D-1 : Silent Speech Recognition Based on Short-Range Millimeter-Wave Sensing
A new silent-speech recognition technique based on a compact custom-designed 120 GHz interferometric radar system is proposed. The millimeter-wave 120 GHz makes it possible to precisely track the fine displacement of the mouth movement, which is strictly related to the speech activities. To overcome the phase ambiguity in millimeter-wave non-linear phase modulation, a novel algorithm based on trigonometric transform is proposed to linearly reconstruct the phase information of the speech. The proposed technique carries the merits of contact-free, high penetrability and high precision. Experiments have been performed in the office environment and the results show that the proposed technique performs well in sensing the precise silent-speech commands for both words and sentences. The specific patterns existing in each command provide foundation for silent-speech recognition.
Technology for in-cabin non-contact monitoring of driver vital signs is a growing area of interest for automotive applications. This has been spurred in part by successful demonstrations of remote sensing of human physiological motion using radar, for healthcare applications. However, most reported physiological radar results have focused on the use of continuous wave radar operating between the 2.4 GHz up to 24 GHz, to monitor a single, isolated subject. There is a recent paradigm shift in the automotive radar industry towards the use of W-band frequency modulated continuous wave radar. This research investigates the feasibility of extracting vital signs information for both single and multi-subject scenarios, utilizing a newly developed 76–81 GHz FMCW single channel architecture automotive radar. Chirp parameters and signal processing steps were developed to extract phase information for signals reflected from tiny movement of a subject’s chest surface. Beam steering techniques were used to isolate the respiratory signatures for individual subjects from radar signals reflected simultaneously from multiple subjects. Experimental results showed that independent respiratory signatures could be isolated and measured for subjects separated by a 30° angular discrimination limit.
📺 We3D-3 : Multi-Spectral THz Micro-Doppler Radar Based on a Silicon-Based Picosecond Pulse Radiator
In this paper, THz vibrometry using a custom picosecond pulse radiator is demonstrated. THz vibrometry is based on the micro-Doppler phenomenon, in which the periodic movement of radar targets modulates the frequency of the electromagnetic waves reflected from their surface. The modulation depth depends on the amount of surface displacement and the carrier frequency. Since the micro-Doppler effect is stronger at higher frequencies, vibrometry in THz band benefits from higher sensitivity compared to RF and mm-wave. In this experiment, sound vibrations with the frequency ranging from 100 Hz to 1 kHz were used to modulate THz carrier tones produced by a broadband THz pulse radiating silicon chip. A music track, a chirp sound, and multiple frequency tones were produced by a speaker, and then were recovered by the downconversion of the modulated THz tone and analog demodulation at the receiver. Additionally, a phase-noise reduction technique is introduced to boost the sensitivity of low-frequency micro-Doppler detection.
📺 We3D-4 : Using FMCW Radar for Spatially Resolved Intra-Chirp Vibrometry in the Audio Range
Many applications require low-cost vibration monitoring. Here we present a robust method for spatially resolved non-contact vibrometry with frequency modulated continuous wave (FMCW) radar sensors. Our newly found technique uses an intermediate phase evaluation, thus allows for measuring faster than the radar sensors chirp rate. We verified our theory with experiments using an 80 GHz highly synchronous ultra-wideband mmWave radar system. In this way, we reached sub-micrometer measurement precision with vibration frequencies up to 16 kHz. Furthermore, we showed that our method enables a clear separation of various vibrating radar targets.
📺 We3D-5 : AI-Driven Event Recognition with a Real-Time 3D 60-GHz Radar System
A vertically integrated antennas-to-AI system is presented. 60-GHz 16-element phased array transmitter and receiver modules, previously developed for Gb/s NLOS communications, are used to implement a 3D radar system that extracts volumetric information from a scene at a high frame rate. The system employs an FMCW signal with 1-GHz bandwidth and can process 1250 radar readouts per second. An efficient timing control scheme between the radar electronics and the phased array module control enables obtaining each of the radar readouts from a separate beam direction. The system can scan a frame of 5×5 directions 50 times per second. All the radar system components including signal generation and ADC are assembled in a single portable chassis. A camera is also included in the system to enable the simultaneous capture of radar and video streams. A DNN was developed to extract temporal and volumetric features from the 3D radar information stream and enable the automatic recognition of fast evolving events. As an application example, the DNN was trained to perform automatic hand gesture recognition. The overall radar system and the associated DNN achieved a recognition accuracy of 93% on a set of 9 different gestures involving two hands.
Novel formulation of the Surface-Volume-Surface Electric Field Integral Equation (SVS-EFIE) for rigorous full-wave electromagnetic analysis of composite metal-dielectric structures embedded in planar multilayered medium is proposed. Handling of multilayered medium dyadic Green’s function (DGF) is based on Michalski-Zheng’s mixed-potential formulation and does not require introduction of any additional components compared to those featured in the traditional mixed-potential integral equation (MPIE) formulations for the analysis of metal structures in layered medium. Characterization of microwave circuits and interconnect structures embedded in dielectric substrates featuring finite dielectric inclusions are among applications well suited for handling with the new single source integral equation formulation. Proposed methodology is validated through comparison of extracted network parameters of realistic 3D model of LTCC diplexer against those obtained with a commercial electromagnetic analysis tool.
Method of moments analysis of planar multi-layer circuits typically assumes conductors are infinitely thin and only surface currents need be modeled. Modern fabrication methods, especially for high frequency integrated circuits, can easily create structures that require modeling volume current. Combined with previous work, this paper presents, for the first time, a complete volume current based method of moments analysis of shielded multi-layer circuits. The new volume and the original surface subsections are all evaluated to full numerical precision by 2-D FFT and have little impact on analysis speed.
📺 Tu2H-3 : Multiphysics Sensitivity Analysis in FDTD Based Electromagnetic-Thermal Simulations
We present a new framework for multiphysics sensitivity analysis with the Finite-Difference Time-Domain (FDTD) method and apply it to joint electromagnetic-thermal simulations. Electromagnetic field and temperature derivatives with respect to uncertain input parameters, such as the complex permittivity of a biological tissue, are computed in a single FDTD simulation. Instead of finite-difference based derivative computations, we use the complex-step derivative approximation, which is robust as free of subtractive cancellation errors and straightforward to integrate with existing FDTD codes for first and higher order derivatives.
📺 Tu2H-4 : Application of Conformal Mapping to Rigorous Validation of 2D Coupled EM-CFD Modelling
This paper proposes a quasi-analytical methodology for validating numerical algorithms coupling electromagnetics with heat transfer and fluid flow phenomena. With the increasing interest in Multiphysics modelling in e.g. application of microwave power to biomedical research, it is crucial to prove accuracy of the coupled algorithms as they popularly serve as virtual prototyping tools in the recent research works. For that purpose a conformal mapping technique combined with Fourier series expansion is proposed and compared with coupled FDTD computation for two benchmark models involving microwave heating and fluid flow phenomena.
📺 Tu2H-5 : The Entropy Technique for the Time-Reversal Source Reconstruction
Electromagnetic inverse problems have been traditionally solved in frequency domain. The time-reversal method has been developed to offer an alternative approach in time domain with natural time stepping computations. However, in its applications to electromagnetic source reconstruction, much work so far has not considered possible different excitation times. In this paper, the concept of entropy used in image processing is incorporated into the time-reversal process, which leads to reconstructions of not only the spatial locations but also the excitation times of the sources. Experiments are also set up for verification purposes and the proposed work may pave the way for practical applications of the time-reversal method. The effectiveness of the method is proposed to solve realistic problems in future experimental test.
Digital-intensive ultra-low-power (ULP) wireless transmitters (TX) employing harmonic injection locking suffer from large close-in reference spurs that violates the TX spectral mask. This paper presents a self-aligned type-I PLL in conjunction with harmonic injection locking to achieve significantly improved spur performance at ULP for sub-GHz IoT TXs. The on-chip type-I PLL calibrates the phase error in the ring oscillator (RO) in real time and avoid large spurs induced from the frequency deviation in the harmonic injection-locked technique through the proposed twin-T notch filter in the feedback loop. Implemented in 180nm CMOS process, the proposed frequency translating TX occupies an active area of only 0.0413mm² with -14dBm output at 915MHz. We report the lowest power consumption with 3X improved energy-efficiency while consistently achieving >62dBc spur suppression. The TX also supports OOK modulation with an average power consumption of 200.9µW only at 3Mb/s data rate achieving 66.97pJ/bit energy efficiency.
📺 Tu2A-2 : A 67-µW Ultra-Low Power PVT-Robust MedRadio Transmitter
A 400 MHz narrowband MedRadio transmitter for short-range communication is presented. A new technique for PVT-robust, calibration- and regulation-free synthesis of the RF carrier is reported based on generating poly-phasors at 50 MHz with no power overhead. This is accomplished using a passive polyphase filter directly integrated within a crystal oscillator followed by an 8× edge combiner to synthesize the RF carrier with -109 dBc/Hz phase noise at 100 kHz offset. A dual supply, inverse class-E power amplifier is implemented for high efficiency at low output power (-17.5 dBm). Open-loop operation permits aggressive duty-cycling (< 40 ns start-up time). State-of-the-art ultra-low power is reported from a prototype BPSK transmitter fabricated in 22 nm CMOS FDX when operated from a 0.4/0.2 V supply consuming 67 µW with 27% global efficiency.
📺 Tu2A-3 : A 400MHz/900MHz Dual-Band Ultra-Low-Power Digital Transmitter for Biomedical Applications
This paper presents a 400MHz/900MHz dual-band ultra-low-power digital transmitter with high energy efficiency for biomedical applications. Direct modulation at local oscillator and digital power amplifier is adopted to simply the transmitter architecture. With edge combining, the dual band transmitter shares a single digital controlled ring oscillator. The 400MHz transmitter adopts 16QAM modulation scheme with the ring oscillator under injection-locked while the 900MHz transmitter adopts BFSK with open loop ring oscillator. Fabricated in 65nm CMOS, the chip occupies an area of 1.3mm². Under 0.5V supply voltage, both band transmitters consume less than 0.6mW power while delivering -15dBm of output power and the 400MHz transmitter achieves an energy efficiency of 53pJ/bit. The measured EVM is 4.35% for 16QAM at 10Mbps and the FSK error is 5.08% at 2Mbps.
This paper presents a 1.3 µW backscatter-based transceiver for battery-powered millimeter-scale sensor nodes. By taking advantage of the coherence of reflected dual-side bands, it attains an optimum SNR and improved interference rejection with low-power, non-coherent binary modulation. Integrated with a 2.1×4 mm planar antenna in a complete, crystal-less sensor node, it achieves a 3.5 m communication distance with a reader transmitting 31 dBm equivalent isotropic radiated power (EIRP).
📺 Tu2A-5 : A Fully Integrated 0.2V 802.11ba Wake-Up Receiver with -91.5dBm Sensitivity
A standalone, fully integrated 0.2V 578µW ultra-low voltage (ULV) 2.4GHz 802.11ba WiFi wake-up receiver (WRX) is presented. It includes a current-efficient ULV noise cancelling LNA with a high turn step-up transformer, and Q-enhanced RF gain stages for low noise figure. A 1/3 fRF mixer and ULV FLL are implemented to reduce current. The chip includes micro-power managers for regulating all internal voltages from a single 0.2V supply. Fabricated in 40nm CMOS, the ULV WRX achieves -91.5dBm sensitivity at 10-3 BER and data-rate of 62.5kbps, while rejecting a 45dB adjacent blocker with only 0.2V supply. The WRX includes an energy-efficient 5ms startup sequence which interfaces to an external node controller over serial peripheral interface (SPI).
This paper describes a high order programmable frequency multiplier in the 60 GHz band. The circuit implements four chains that can address simultaneously four different frequencies of the IEEE 802.11ay standard and aims to channel bonding, full duplex, or MIMO systems. It is fabricated in a 45nm CMOS PDSOI technology. Each chain consumes 32.6mW and achieves lower than 178fsec of integrated jitter (in the band 10KHz–1.08GHz) for all synthesized frequencies.
This paper presents a fully integrated oscillator-less frequency-comb receiver for broadband sensing, spectroscopy, and imaging in millimeter-wave and THz bands. The chip consists of a THz pulse generator block to generate the reference tones for coherent frequency comb detection. The repetition rate of the reference pulses (LO frequency comb) are tunable over a 4–10.5 GHz range, with the highest sensitivity achieved at 9 GHz. A broadband on-chip antenna with a peak directivity of 15 dBi is employed for broadband detection. The receiver, which is capable of detecting any arbitrary spectrum, is characterized from 140 GHz to 500 GHz using continuous-wave sources. Peak sensitivity of -105 dBm is achieved at 261 GHz. The chip is implemented in 130-nm SiGe BiCMOS technology and consumes only 52-mW DC power. The chip can also be used as a frequency comb radiator. Chip-to-chip dual-comb measurement is performed using two identical chips in the radiator and receiver modes, respectively up to 450 GHz.
📺 Mo4B-3 : A SiGe Millimeter-Wave Front-End for Remote Sensing and Imaging
This work presents the co-design of a millimeter-wave (mm-wave) switch with a low-noise amplifier (LNA), in which the front-end switch incorporates a transformer-based topology and serves as the LNA input matching network. This mm-wave front-end is implemented in a 0.13µm SiGe BiCMOS technology and achieves a peak gain of 20.1 dB, a minimum noise figure of 4.5 dB, and a mean isolation of 17 dB. The input reflection coefficient is less than -15 dB over 45–70 GHz. An avalanche noise source using a diode-configured SiGe HBT is also integrated in the front-end for two-reference on-chip calibration, which can provide up to a high excess noise ratio of 25 dB. The LNA consumes a DC power of 15 mW and occupies a chip area of 0.6 mm². To the best of our knowledge, this is the lowest reported noise figure of an integrated switch and LNA at V-band frequencies and is the first monolithic two-reference calibrating mm-wave SiGe radiometer front-end.
📺 Mo4A-2 : Spatio-Temporal Filtering: Precise Beam Control Using Fast Beam Switching
This paper presents a spatio-temporal filtering approach for beamforming with phased arrays. The approach takes advantage of fast beam switching in modern Si-integrated phased arrays enabled by integrated digital circuits. The key technique involves fast switching among spatial beams created using the phased array. The resulting time-averaged beam represents a new spatial filter that might not have been feasible using the phase and gain control resolution available in the phased array. We present the underlying theory, and perform extensive system measurements on a software defined phased array radio based on state-of-the-art 28GHz phased array ICs. We demonstrate three use cases of spatio-temporal beam control in measurement: a) side lobe reduction, b) multi-armed beam formation and c) null pointing. We demonstrate how this approach can enable high precision beam control even in systems with limited phase shifter resolution and/or systems without any gain control per antenna element.
An integrated look-ahead DFS scheme relies on having a dedicated low-cost receiver that constantly scans the WiFi band for radar existence. A table of radar-occupied WiFi channels is constructed as a result. When it is time to switch channels upon radar in-channel detection, the WiFi transceiver can directly jump to an empty channel without having to sniff for 60s, as required by FCC/ETSI regulations. The scheme results in zero-wait time and zero impact to WiFi throughput. Circuit implementation relies on reusing some readily existing hardware in a 55nm CMOS n×n MIMO WiFi transceiver to reduce die cost.
We present an RF clock distribution system for a fully integrated and scalable quantum processor core operating at 3.8 K. An external 2.4 GHz signal is guided from the generator to the flip-chip package IC through a cryogenic coaxial cable. The choice of coaxial cable and the clock routing design on the PCB and IC, minimizes path loss and coupling to the supplies, the I/O signals, and more importantly the sensitive quantum core. The clock integrity up to the quantum core is maintained and verified by the jitter measurement of 0.8 ps from a test port while all circuitry within the cryo-cooler operates within the thermal load specification of 1.5W.
We propose an architecture for mobile RF transceivers which integrates RISC-V micro-controller unit (MCU) to control its internal function without requiring multiple chip-to-chip control messages from the modem. The proposed architecture is utilized to perform 5G millimeter wave (mmWave) control tasks including beamforming and temperature dependent gain compensation. The control architecture including MCU and its subsystem occupies 0.258 mm² in 28-nm process, and consumes 2.61 mW at 140 MHz (18 µW/MHz). Based on the evaluation results, our proposed architecture enables control of 5G mmWave RF transceivers.
📺 B-1: A Cryogenic Quantum-Based RF Source
📺 B-2: Modulation Distortion Analysis for Mixers and Frequency Converters
📺 B-3: Swept Notch NPR for Linearity Assessment of Systems Presenting Long-Term Memory Effects
📺 B-4: Vector Gain Based Behavioral Models for Distortion Evaluation in mm-Wave Devices
📺 D-1: Cryogenic Calibration of a Quantum-based Radio Frequency Source
📺 D-3: Setup and Control of a Millimeter-Wave Synthetic Aperture Measurement System with Uncertainties