Radar Transceiver Research Articles

A Packaged 54-to-69-GHz Wideband 2T2R FMCW Radar Transceiver Employing Cascaded-PLL Topology and PTAT-Enhanced Temperature Compensation in 40-nm CMOS

A Packaged 54-to-69-GHz Wideband 2T2R FMCW Radar Transceiver Employing Cascaded-PLL Topology and PTAT-Enhanced Temperature Compensation in 40-nm CMOS

Differential-Mode Power Detection for Built-In Self-Test of SiGe Automotive Radar Transceiver Front Ends

Differential-Mode Power Detection for Built-In Self-Test of SiGe Automotive Radar Transceiver Front Ends

A 1T2R Heterogeneously Integrated Phased-Array FMCW Radar Transceiver With AMC-Based Antenna in Package in the W-Band

A 1T2R Heterogeneously Integrated Phased-Array FMCW Radar Transceiver With AMC-Based Antenna in Package in the <i>W</i>-Band

High‐resolution 3D imaging by microwave photonic time division multiplexing‐multiple‐input‐multiple‐output radar with broadband digital beamforming

AbstractA broadband microwave photonic time division multiplexing (TDM) multiple‐input‐multiple‐output (MIMO) radar is proposed in which photonic frequency quadrupling is adopted to generate broadband radar signals and photonic frequency mixing is implemented for de‐chirping processing of radar echoes. By utilising two radio frequency switches to control the signal transmission and reception, TDM‐MIMO mechanism is formed using a single microwave photonic radar transceiver. This microwave photonic TDM‐MIMO radar not only achieves high range resolution using broadband processing but also enables high angular resolution and forward‐looking imaging capability with low system complexity. Besides, a broadband digital beamforming (DBF) method is introduced to solve the broadband beam squint and broadening problems and implement near‐field correction. In the experiment, a microwave photonic TDM‐MIMO radar with an 8×8 T‐shape antenna array is established with a bandwidth of 8 GHz (18–26 GHz) in each channel. The range and angular resolutions are estimated to be ∼2 cm and ∼2°, respectively. Applying the broadband DBF method, high‐resolution 3D imaging of small targets is achieved with good focusing of targets and deep suppression of grating lobes and side lobes. Hence, the proposed microwave photonic TDM‐MIMO radar with broadband DBF provides a promising solution for high‐resolution 3D imaging.

Robust Ku-Band GaN Low-Noise Amplifier MMIC

This paper employs the 0.2 μm ETRI GaN HEMT process on SiC to develop a Ku-band GaN low-noise amplifier monolithic microwave integrated circuit (MMIC) characterized by high-input power robustness for radar transceiver modules. A source degeneration inductor is employed to obtain the proposed amplifier’s stable operation and the compromised impedance trajectory of the maximum available gain and minimum noise figure. The analysis results show simultaneous gain and noise impedance matching, achieved using only a small number of passive elements. Furthermore, the proposed low-noise amplifier MMIC secures a linear gain of 21.3−22.6 dB, an input return loss of 19.6−21.4 dB, and a noise figure of 1.7−1.8 dB in the 15–16 GHz frequency range. It also exhibits an input 1 dB compression point of 0.4−1.5 dBm in the single-tone power test, and an input third-order intercept point of 5.8−10.1 dBm within the 15−16 GHz frequency range in the two-tone intermodulation distortion test.

Combining 77–81 GHz MIMO FMCW radar with frequency-steered antennas: a case study for 3D target localization

Abstract In this paper, we introduce a compact 6 × 8 channel multiple-input multiple-output frequency-modulated continuous-wave radar system capable of determining the three-dimensional positions of targets despite utilizing a linear virtual array. The compact system, containing two cascaded radar transceiver ICs, has 48 virtual channels. We conduct a direction of arrival estimation with these virtual channels to determine the azimuth angle. To overcome the spatial limitation of the linear array, we use frequency-steered transmit antennas, which vary their main lobe direction during the frequency chirp, allowing the elevation angle to be determined by using a sliding window fast Fourier transform algorithm. In this study, we present the system’s concept along with the associated signal processing. By taking measurements in different scenarios, each with differently placed corner reflectors, we investigate the capability of the system to separate adjacent targets concerning range, azimuth, and elevation. These measurements are additionally employed to point out the design trade-offs inherent to the system.

Fully Integrated 24-GHz 1TX-2RX Transceiver for Compact FMCW Radar Applications.

A fully integrated 24-GHz radar transceiver with one transmitter (TX) and two receivers (RXs) for compact frequency modulated continuous wave (FMCW) radar applications is here presented. The FMCW synthesizer was realized using a fractional-N phase-locked loop (PLL) and programmable chirp generator, which are completely integrated in the proposed transceiver. The measured output phase noise of the synthesizer is -80 dBc/Hz at 100 kHz offset. The TX consists of a three-bit bridged t-type attenuator for gain control, a two-stage drive amplifier (DA) and a one-stage power amplifier (PA). The TX chain provides an output power of 13 dBm while achieving <0.5 dB output power variation within the range of 24 to 24.25 GHz. The RX with a direct conversion I-Q structure is composed of a two-stage low noise amplifier (LNA), I-Q generator, mixer, transimpedance amplifier (TIA), a two-stage biquad band pass filter (BPF), and a differential-to-single (DTS) amplifier. The TIA and the BPF employ a DC offset cancellation (DCOC) circuit to suppress the strong reflection signal and TX-RX leakage. The RX chain exhibits an overall gain of 100 dB. The proposed radar transceiver is fabricated using a 65 nm CMOS technology. The transceiver consumes 220 mW from a 1 V supply voltage and has 4.84 mm2 die size including all pads. The prototype FMCW radar is realized with the proposed transceiver and Yagi antenna to verify the radar functionality, such as the distance and angle of targets.

An optimized sparse deep belief network with momentum factor for fault diagnosis of radar transceivers

Transceiver is a crucial component of radar system that allows for the regulation of signal phase and amplitude as well as the amplification of both transmitted and received signals. Its operational efficiency has a significant impact on the whole dependability of the radar system. To ensure the safe and reliable operation of the radar system, an optimized sparse deep belief network with momentum factor is developed to diagnose potential faults of radar transceivers. Firstly, a momentum term is added into the parameter update to enhance the anti-oscillation ability of model parameters in training, while a sparse regular term is integrated into the deep belief network to prevent the model from overfitting. Secondly, to automatically configure the model hyper-parameters, a hybrid sine cosine algorithm (HSCA) with dynamic inertia weight and adaptive strategies is proposed. Thus, an effective diagnostic model named HSCA-MS-DBN is formed by combining sparse deep belief network with momentum factor and HSCA. The efficiency of the proposed HSCA-MS-DBN model is confirmed using an actual-world radar transceiver dataset, and the findings from experiments reveal that this model surpasses multiple prominent intelligent models.

A 140-GHz FMCW Radar Transceiver With Dual-Lens Packaging for Improved Beam Alignment in 65-nm CMOS Technology

A 140-GHz FMCW Radar Transceiver With Dual-Lens Packaging for Improved Beam Alignment in 65-nm CMOS Technology

A Two-Stage Fault Diagnosis Method With Rough and Fine Classifiers for Phased Array Radar Transceivers

A Two-Stage Fault Diagnosis Method With Rough and Fine Classifiers for Phased Array Radar Transceivers

A compact and fully integrated FMCW radar transceiver combined with a dielectric lens

Abstract Electronic measurement systems in the THz frequency range are often bulky and expensive devices. While some compact single-chip systems operating in the high millimeter-wave frequency range have recently been published, compact measurement systems in the low THz frequency range are still rare. The emergence of new silicon-germanium (SiGe) semiconductor technologies allow the integration of system components, like oscillators, frequency multipliers, frequency dividers, and antennas, operating in the low THz frequency range, into a compact monolithic microwave integrated circuits (MMIC), which contains most components to implement a low-cost and compact frequency-modulated continuous-wave-radar transceiver. This article presents a single transceiver solution containing all necessary components. It introduces a $0.48\,\mathrm{THz}$ radar transceiver MMIC with a tuning range of $43\,\mathrm{GHz}$ and an output power of up to $-9.4\,\mathrm{dBm}$ in the SG13G3 $130\,\mathrm{nm}$ SiGe technology by IHP. The MMIC is complemented by a dielectric lens antenna design consisting of polytetrafluoroethylene, providing up to $39.3\,\mathrm d\mathrm B\mathrm i$ of directivity and half-power beam widths of 0.95∘ in transmit and receive direction. The suppression of clutter from unwanted targets deviating from antenna boresight more than 6∘ is higher than $24.6\,\mathrm d \mathrm B$ in E- and H-Plane.

A 223–276-GHz Cascadable FMCW Transceiver in 130-nm SiGe BiCMOS for Scalable MIMO Radar Arrays

This article reports a 223–276-GHz monostatic frequency-modulated continuous-wave (FMCW) radar transceiver (TRX) chip. The TRX is suitable for building massive multiple-input multiple-output (MIMO) radar arrays in the daisy-chain topology because of its cascadable feature based on the injection-locking feedthrough technique. The TRX is based on 18 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> frequency multiplication chain that can be fed by either an external signal generator (SG) or its internal voltage-controlled oscillator (VCO). The modulation bandwidth (BW) is about 53 GHz when the internal VCO is activated, resulting in a range resolution of better than 3 mm. The peak output power is 3.1 dBm at 240 GHz with a 3-dB BW of 41 GHz. Its receiver (RX) channel is based on the in-phase/quadrature architecture enabling complex signal sampling. The minimum single-sideband (SSB) noise figure (NF) is 18.7 dB at 255 GHz, and the average value is 20.7 dB. The TRX chip includes an on-chip antenna coupled with a silicon lens, offering a peak effective isotropic radiated power (EIRP) of 27 dBm at 240 GHz. The TRX consumes a dc current of 234 and 270.1 mA from a single supply voltage of 3.3 V for external and internal VCO operations, respectively. The chip occupies a total area of 2.7 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (2.16 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 1.26 mm).

Design of Wideband FMCW Radar Transceiver System Using Photonic Elements.

This paper proposes a FMCW radar transceiver with photonic elements. The proposed radar system is efficiently designed by budget analysis, and a wideband signal is generated using photonic elements. To verify the performance of the proposed radar system, field tests including changes in bandwidth are conducted. The results confirm that the resolution of ISAR images improves as the bandwidth increases as expected through the budget analysis.

An X-Band Multifrequency Difference Frequency-Shift Keying CMOS Radar for Range Tracking and AI-Based Human Gesture Recognition

This article presents an X-band single-chip fully integrated multi-frequency difference frequency-shift keying (FSK) I/Q direct-conversion radar transceiver implemented in a 130-nm CMOS process. Combined with the artificial intelligence (AI)-based algorithm, accurate gesture recognition are realized. The PLL-based dual-frequency difference FSK waveform and ranging algorithm are proposed to solve the trade-off between the maximum unambiguous range and the ranging accuracy. The loop bandwidth optimized integer-N phase-locked loop (PLL) is integrated to generate standard-compliant FSK signals with predictable frequency difference. The relationship between instantaneous ranging bias and PLL loop parameters is analyzed in detail. The proposed bias noise filter fully suppresses the flicker noise and improves the receiver noise figure (NF). The quadrature signal generator (QSG) adopts a fully differential amplifier buffered resistance compensation quadrature all-pass filter (QAF) to improve the I/Q balance and insertion loss. The chip consumes a current of 56-mA, and provides a conversion gain (CG) of 22-102 dB. The single-ended transmit power is 1.5-dBm. To the best of our knowledge, the implemented transceiver is the first recorded X-band FSK radar transceiver and provide a low-cost solution for indoor human detection.

X-band MMICs for a Low-Cost Radar Transmit/Receive Module in 250 nm GaN HEMT Technology

This paper describes Monolithic Microwave Integrated Circuits (MMICs) for an X-band radar transceiver front-end implemented in 0.25 μm GaN High Electron Mobility Transistor (HEMT) technology. Two versions of single pole double throw (SPDT) T/R switches are introduced to realize a fully GaN-based transmit/receive module (TRM), each of which achieves an insertion loss of 1.21 dB and 0.66 dB at 9 GHz, IP1dB higher than 46.3 dBm and 44.7 dBm, respectively. Therefore, it can substitute a lossy circulator and limiter used for a conventional GaAs receiver. A driving amplifier (DA), a high-power amplifier (HPA), and a robust low-noise amplifier (LNA) are also designed and verified for a low-cost X-band transmit-receive module (TRM). For the transmitting path, the implemented DA achieves a saturated output power (Psat) of 38.0 dBm and output 1-dB compression (OP1dB) of 25.84 dBm. The HPA reaches a Psat of 43.0 dBm and power-added efficiency (PAE) of 35.6%. For the receiving path, the fabricated LNA measures a small-signal gain of 34.9 dB and a noise figure of 2.56 dB, and it can endure higher than 38 dBm input power in the measurement. The presented GaN MMICs can be useful in implementing a cost-effective TRM for Active Electronically Scanned Array (AESA) radar systems at X-band.

A fully integrated ultra-low noise low-dropout regulator inherently combined with bandgap reference for SoC applications

This paper presents a capacitor-less ultra-low noise low-dropout regulator (LDO) inherently combined with bandgap reference (BGR). Compared to traditional LDOs with a dedicated error amplifier (EA) followed by a BGR to generate a variety of desired output voltages through power transistors, the proposed LDO uses a novel architecture, which employs a BGR inherently combined with LDO sharing the same operational amplifier (OPA) for the voltage generation. By doing so this architecture not only reduces LDO’s power consumption and design complexity, but also greatly improves its low-frequency noise characteristic due to much less noise contribution from the active part of EA. The design procedure of the proposed LDO is presented with its implementation in the 40 nm CMOS process. The post-simulation results show that the output voltage ranges from 1.27 V to 2.67 V at a power supply of 3.3 V, with an average temperature coefficient (TC) of 11.9 ppm/°C over a temperature range (TR) of −40 °C to 125 °C. With an LDO output voltage of 1.27 V and a load current of 10 mA, the output noise is as low as 2.61 μV/Hz at 1 Hz and the integrated noise is 5.09 μVRMS from 1 Hz to 100 Hz. The quiescent current is only 30 μA in standby mode. The proposed LDO occupies an area of 0.036 mm2. This ultra-low noise LDO is quite suitable for low-frequency signal conditioning circuit and system design, such as Doppler radar transceivers and bio-medical circuit and system.

An Efficient Full Wave Model for Investigating Layered Media Using Bi-Static Ground Penetrating Radar

Ground penetrating radar (GPR) is a popular non-destructive sensor for subsurface media investigation. Modelling of the GPR system has a significant role in the successful estimation of sub-surface media properties, imaging, and detection of buried object. A model should provide good accuracy and computational efficiency while taking care of numerous GPR scenarios. However, achieving accuracy and speed of computation is a difficult task. In this respect, analytical modellings are promising techniques to represent a specific GPR scenario. In this work, a simplified full wave model (FWM) for bi-static GPR has been developed to represent radar transceivers with layered media. The model has been derived from an existing full wave model (FWM) solution. The accuracy of the proposed model has been verified by comparing it with existing FWMs, and by laboratory experiments based on stepped frequency continuous wave (SFCW) GPR. The corresponding results show that the proposed bi-static model is as accurate as FWM and its computational efficiency is enormous in estimating the sub-surface media properties.

A 0.9 - 1.5 GHz CMOS UWB Radar IC for Through the Wall Human Detection

In this paper, a UWB radar IC for the through wall radar is presented to achieve the smaller form factor of the module and low power operation. For the penetration performance enhancement, the radar IC s designed for the lower 0.9 – 1.5 GHz band. The radar IC employs the 4-channel time-interleaved equivalent time sampling receiver for 200 ps fine resolution, and the digitally synthesized impulse generator for the transmitter. The human target behind the concrete brick wall can be detected in the distance over 9.4 m with the help of signal processing part and additional amplifiers. The radar transceiver IC is fabricated in a 0.13 μm CMOS technology and the current consumption is 116.3 mA at the 1.2 V supply.

Gapwaveguide Automotive Imaging Radar Antenna With Launcher in Package Technology

A 77 GHz gapwaveguide radar antenna system with launcher-in-package (LiP) technology is presented in this paper for automotive imaging applications. Firstly, state-of-the-art LiP technology integrated with radar transceivers is proposed. The transceivers are equipped with waveguide interfaces for RF connection, enabling direct integration with waveguide antennas. Robust interconnects for coupling transceivers to waveguide antennas with non-galvanic contacts are proposed using gapwaveguide packaging technology. A simultaneous multi-mode imaging radar system using 4 cascaded aforementioned transceivers is introduced. Designated antenna elements of the system are realized by slot arrays with center-fed ridge gapwaveguides. Ultimately, the imaging radar antenna has a top radiating slot layer, a middle distribution layer and a bottom interconnect layer capable of accommodating 4 LiP radar transceivers with considerable assembly tolerance which is really one of the key aspects for commercial automotive radar applications. Input matching and radiation patterns of the antenna are verified by measurement. The results indicate that the proposed gapwaveguide imaging radar antenna in conjunction with the novel LiP packaging is able to serve the radar system properly. To the best of the authors’ knowledge, the proposed gapwaveguide antenna system is the first imaging radar antenna system ever developed for LiP components. This work provides a compact, high-efficiency and cost-effective solution for the integration of complex radar systems with waveguide antennas.

Wideband and Efficient 256-GHz Subharmonic- Based FMCW Radar Transceiver in 130-nm SiGe BiCMOS Technology

This article proposes a fully integrated single-channel bistatic frequency-modulated continuous-wave (FMCW) radar transceiver (TRX) that operates at a center frequency of 256 GHz. The main focus of this work is to realize a wideband and efficient radar TRX that offers high resolution of target detection in the short-range FMCW radar sensing application. The radar TRX chip is designed and manufactured using the 130 nm silicon–germanium (SiGe) bipolar complementary metal-oxide-semiconductor (BiCMOS) technology which offers heterojunction bipolar transistors (HBTs) with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{\mathbf {T}}/f_{\mathbf {MAX}}$ </tex-math></inline-formula> of 300/500 GHz. The transmitter (TX) of the radar TRX is based on a fundamentally operated multiplier-by-8 chain architecture that offers a 3-dB bandwidth of around 65 GHz with a saturated output power of −5.4 dBm. On the other hand, the receiver (RX) is based on a subharmonic architecture that provides a conversion gain (CG) of 10.4 dB with an average noise figure (NF) of 23.5 dB. This TRX is realized with two integrated on-chip folded dipole antennas. The antenna offers high antenna gain and radiation efficiency due to the use of the selective localized backside etching (LBE) technique. This chip consumes 305 mW of power from a 3.3-V supply and occupies a silicon area of 3.3 mm2. The radar range measurement is performed in an anechoic chamber, and it shows the maximum dynamic range (DR) of around 34 dB at 1-m range of the target.