High Accuracy Motion Detection Algorithm via ISM Band FMCW Radar

The conventional frequency modulated continuous wave (FMCW) radar accuracy range detection algorithm is based on the frequency estimation and additional phase evaluation which contains Fourier transform and frequency refining analysis in each chirp, so it has the disadvantages of being computationally expensive, and not being suitable for real-time motion measurement. In addition, if there are other objects near the target, the spectra of the clutter and the target will be adjacent and affect each other, making it more challenging to estimate the frequency of the target. In this paper, the analytical expression of the Fourier transform of the beat signal is presented and it can be seen that spectrum leakage makes the phase of Fourier transform no longer consistent with the real phase of signal. The change regularities of real and imaginary parts of Fourier transform are studied, and the corrected phase of ellipse approximation is given in the industrial, scientific, and medical (ISM) band. Accurate displacement can be obtained by accurate phase. The algorithm can filter the direct current (DC) offset which is mainly caused by stationary objects. The performance of the algorithm is evaluated by a radar system whose center frequency is 24.075 GHz and the bandwidth is 0.15 GHz; the measurement accuracy of displacement is 0.087 mm and the accuracy of distance is 0.043 m.

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Low-Complexity MUSIC-Based Direction-of-Arrival Detection Algorithm for Frequency-Modulated Continuous-Wave Vital Radar

Sensors ◽

10.3390/s20154295 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4295 ◽

Cited By ~ 1

Author(s):

Bong-seok Kim ◽

Youngseok Jin ◽

Jonghun Lee ◽

Sangdong Kim

Keyword(s):

Fourier Transform ◽

Fast Fourier Transform ◽

Continuous Wave ◽

Direction Of Arrival ◽

Doa Estimation ◽

Low Complexity ◽

Detection Algorithm ◽

Field Of View ◽

Music Algorithm ◽

Trade Offs

This paper proposes a low complexity multiple-signal-classifier (MUSIC)-based direction-of-arrival (DOA) detection algorithm for frequency-modulated continuous-wave (FMCW) vital radars. In order to reduce redundant complexity, the proposed algorithm employs characteristics of distance between adjacent arrays having trade-offs between field of view (FOV) and resolution performance. First, the proposed algorithm performs coarse DOA estimation using fast Fourier transform. On the basis of the coarse DOA estimation, the number of channels as input of the MUSIC algorithm are selected. If the estimated DOA is smaller than 30°, it implies that there is an FOV margin. Therefore, the proposed algorithm employs only half of the channels, that is, it is the same as doubling the spacing between arrays. By doing so, the proposed algorithm achieves more than 40% complexity reduction compared to the conventional MUSIC algorithm while achieving similar performance. By experiments, it is shown that the proposed algorithm despite the low complexity is enable to distinguish the adjacent DOA in a practical environment.

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Radar Imager for Mars’ Subsurface Experiment—RIMFAX

Space Science Reviews ◽

10.1007/s11214-020-00740-4 ◽

2020 ◽

Vol 216 (8) ◽

Author(s):

Svein-Erik Hamran ◽

David A. Paige ◽

Hans E. F. Amundsen ◽

Tor Berger ◽

Sverre Brovoll ◽

...

Keyword(s):

Continuous Wave ◽

Sand Dunes ◽

Landing Site ◽

Wide Band ◽

Center Frequency ◽

Depth Range ◽

Fmcw Radar ◽

Shallow Subsurface ◽

Eventual Return ◽

Ground Penetrating

AbstractThe Radar Imager for Mars’ Subsurface Experiment (RIMFAX) is a Ground Penetrating Radar on the Mars 2020 mission’s Perseverance rover, which is planned to land near a deltaic landform in Jezero crater. RIMFAX will add a new dimension to rover investigations of Mars by providing the capability to image the shallow subsurface beneath the rover. The principal goals of the RIMFAX investigation are to image subsurface structure, and to provide information regarding subsurface composition. Data provided by RIMFAX will aid Perseverance’s mission to explore the ancient habitability of its field area and to select a set of promising geologic samples for analysis, caching, and eventual return to Earth. RIMFAX is a Frequency Modulated Continuous Wave (FMCW) radar, which transmits a signal swept through a range of frequencies, rather than a single wide-band pulse. The operating frequency range of 150–1200 MHz covers the typical frequencies of GPR used in geology. In general, the full bandwidth (with effective center frequency of 675 MHz) will be used for shallow imaging down to several meters, and a reduced bandwidth of the lower frequencies (center frequency 375 MHz) will be used for imaging deeper structures. The majority of data will be collected at regular distance intervals whenever the rover is driving, in each of the deep, shallow, and surface modes. Stationary measurements with extended integration times will improve depth range and SNR at select locations. The RIMFAX instrument consists of an electronic unit housed inside the rover body and an antenna mounted externally at the rear of the rover. Several instrument prototypes have been field tested in different geological settings, including glaciers, permafrost sediments, bioherme mound structures in limestone, and sedimentary features in sand dunes. Numerical modelling has provided a first assessment of RIMFAX’s imaging potential using parameters simulated for the Jezero crater landing site.

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Developing of Algorithms Monitoring Heartbeat and Respiration Rate of a Seated Person with an FMCW Radar

Advances in Radio Science ◽

10.5194/ars-19-195-2021 ◽

2021 ◽

Vol 19 ◽

pp. 195-206

Author(s):

Lorenz J. Dirksmeyer ◽

Aly Marnach ◽

Daniel Schmiech ◽

Andreas R. Diewald

Keyword(s):

Respiration Rate ◽

Continuous Wave ◽

Frequency Estimation ◽

Wavelet Packet ◽

Vital Signs ◽

Wave Mode ◽

Fine Tuning ◽

Fmcw Radar ◽

Real Time Visualization ◽

Spectral Frequency

Abstract. With a radar working in the 24 GHz ISM-band in a frequency modulated continuous wave mode the major vital signs heartbeat and respiration rate are monitored. The observation is hereby contactless with the patient sitting straight up in a distance of 1–2 m to the radar. Radar and sampling platform are components developed internally in the university institution. The communication with the radar is handled with MATLAB via TCP/IP. The signal processing and real-time visualization is developed in MATLAB, too. Cornerstone of this publication are the wavelet packet transformation and a spectral frequency estimation for vital sign calculation. The wavelet transformation allows a fine tuning of frequency subspaces, separating the heartbeat signal from the respiration and more important from noise and other movement. Heartbeat and respiration are monitored independently and compared to parallel recorded ECG-data.

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Dual-Mode Radar Sensor for Indoor Environment Mapping

Sensors ◽

10.3390/s21072469 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2469

Author(s):

Seongwook Lee ◽

Song-Yi Kwon ◽

Bong-Jun Kim ◽

Hae-Seung Lim ◽

Jae-Eun Lee

Keyword(s):

Indoor Environment ◽

Continuous Wave ◽

Multiple Input Multiple Output ◽

Antenna System ◽

Radar System ◽

Center Frequency ◽

Indoor Environments ◽

Radar Sensor ◽

Dual Mode ◽

Fmcw Radar

In this paper, we introduce mapping results in an indoor environment based on our own developed dual-mode radar sensor. Our radar system uses a frequency-modulated continuous wave (FMCW) with a center frequency of 62 GHz and a multiple-input multiple-output antenna system. In addition, the FMCW radar sensor we designed is capable of dual-mode detection, which alternately transmits two waveforms using different bandwidths within one frame. The first waveform is for long-range detection, and the second waveform is for short-range detection. This radar system is mounted on a small robot that moves in indoor environments such as rooms or hallways, and the radar and the robot send and receive necessary information to each other. The radar estimates the distance, velocity, and angle information of targets around the radar-equipped robot. Then, the radar receives information about the robot’s motion from the robot, such as its speed and rotation angle. Finally, by combining the motion information and the detection results, the radar-equipped robot maps the indoor environment while finding its own position. Compared to the actual map data, the radar-based mapping is effectively achieved through the radar system we developed.

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X-Band Photonic-Based Pulsed Radar Architecture with a High Range Resolution

Applied Sciences ◽

10.3390/app10186558 ◽

2020 ◽

Vol 10 (18) ◽

pp. 6558

Author(s):

Youngseok Bae ◽

Minwoo Yi ◽

Jinwoo Shin ◽

Sang-Gug Lee

Keyword(s):

Continuous Wave ◽

Optical Switch ◽

Pulse Repetition Frequency ◽

Error Rates ◽

Center Frequency ◽

Waveform Generator ◽

Range Resolution ◽

Fmcw Radar ◽

X Band ◽

High Range

In this paper, we propose an X-band photonic-based pulsed radar architecture with a high range resolution. The proposed architecture is operated as a pulsed radar by adding a Mach-Zehnder modulator (MZM) operating as an optical switch to a transmitter of a conventional photonic-based frequency-modulated continuous wave (FMCW) radar. In addition, a balanced photodetector (BPD) is employed to enhance the amplitude of the received signal and remove common-mode noise. A proposed photonic-based pulsed radar prototype is implemented to operate at a center frequency of 10 GHz, a bandwidth of 640 MHz, and a pulse repetition frequency (PRF) of 1 kHz considering the performances of an arbitrary waveform generator (AWG). The implemented prototype is verified through an indoor experiment. As a result, the positions of targets are detected in real-time with 1.6% error rates of a range accuracy and obtained the range resolution of 0.26 m.

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A Low-Complexity FMCW Surveillance Radar Algorithm Using Two Random Beat Signals

Sensors ◽

10.3390/s19030608 ◽

2019 ◽

Vol 19 (3) ◽

pp. 608 ◽

Cited By ~ 8

Author(s):

Bong-seok Kim ◽

Youngseok Jin ◽

Sangdong Kim ◽

Jonghun Lee

Keyword(s):

Fourier Transform ◽

Continuous Wave ◽

Low Complexity ◽

Radar System ◽

Moving Target ◽

Moving Targets ◽

One Dimensional ◽

Fmcw Radar ◽

Target Indicator ◽

Simulation Results

This paper proposes a low-complexity frequency-modulated continuous wave (FMCW) surveillance radar algorithm using random dual chirps in order to overcome the blind-speed problem and reduce the computational complexity. In surveillance radar algorithm, the most widely used moving target indicator (MTI) algorithm is proposed to effectively remove clutter. However, the MTI algorithm has a so-called ‘blind-speed problem’ that cannot detect a target of a specific velocity. In this paper, we try to solve the blind-speed problem of MTI algorithm by randomly selecting two beat signals selected for MTI for each frame. To further reduce the redundant complexity, the proposed algorithm first performs one-dimensional fast Fourier transform (FFT) for range detection and performs multidimensional FFT only when it is determined that a target exists at each frame. The simulation results show that despite low complexity, the proposed algorithm detects moving targets well by avoiding the problem of blind speed. Furthermore, the effectiveness of the proposed algorithm was verified by performing an experiment using the FMCW radar system in a real environment.

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Searching Velocity Fourier Transform: A Novel Focus-Before-Detection Algorithm in FMCW Radar

2020 IEEE Radar Conference (RadarConf20) ◽

10.1109/radarconf2043947.2020.9266408 ◽

2020 ◽

Author(s):

Longhui Wang ◽

Jian Wang

Keyword(s):

Fourier Transform ◽

Detection Algorithm ◽

Fmcw Radar

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A 24 GHz wideband monostatic FMCW radar system based on a single-channel SiGe bipolar transceiver chip

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078713000391 ◽

2013 ◽

Vol 5 (3) ◽

pp. 309-317 ◽

Cited By ~ 6

Author(s):

Christian Bredendiek ◽

Nils Pohl ◽

Timo Jaeschke ◽

Sven Thomas ◽

Klaus Aufinger ◽

...

Keyword(s):

Power Consumption ◽

Phase Noise ◽

Tuning Range ◽

Continuous Wave ◽

Single Channel ◽

Radar System ◽

Center Frequency ◽

Fmcw Radar ◽

24 Ghz ◽

Better Than

In this paper a monostatic frequency-modulated continuous-wave (FMCW) radar system around a center frequency of 24 GHz with a wide tuning range of 8 GHz (≈33%) is presented. It is based on a fully integrated single-channel SiGe transceiver chip. The chip architecture consists of a fundamental VCO, a receive mixer, a divider chain, and coupling/matching networks. All circuits, except for the divider, are designed with the extensive use of on-chip monolithic integrated spiral inductors. The chip is fabricated in a SiGe bipolar production technology which offers an fT of 170 GHz and fmax of 250 GHz. The phase noise at 1 MHz offset is better than −100 dBc/Hz over the full-tuning range of 8 GHz and a phase noise of better than −111 dBc/Hz is achieved at 27 GHz. The peak output power of the chip is −1 dBm while the receive mixer offers a 1 dBm input referred compression point to keep it from being saturated. The chip has a power consumption of 245 mW and uses an area of 1.51 mm2. The FMCW radar system achieves a power consumption below 1.6 W. Owing to the high stability of the sensor, high accuracy mesaurements with a range error <±250 µm were achieved. The standard deviation between repeated measurements of the same target is 0.6 µm and the spatial resolution is 28 mm.

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