Monostatic continuous-wave radar integrating a tunable wideband leakage canceler for indoor tagless localization

2017 ◽  
Vol 9 (8) ◽  
pp. 1583-1590 ◽  
Author(s):  
Marco Mercuri ◽  
Paweł Barmuta ◽  
Ping Jack Soh ◽  
Paul Leroux ◽  
Dominique Schreurs
Keyword(s):  
Health Monitoring ◽  
Continuous Wave ◽  
Dynamic Range ◽  
Passive Microwave ◽  
Ultra Wideband ◽  
Strong Reduction ◽  
Wave Radar ◽  
Microwave Design ◽  
Stepped Frequency ◽  
Cw Radar

Continuous-wave (CW) radars have been recently investigated in healthcare aiming at contactless health monitoring. However, a major problem in monostatic CW architectures is represented by the unwanted leakage produced by poor isolation between transmitter and receiver, which can drastically decrease the receiver's sensitivity reducing therefore the radar dynamic range. Although this situation can be easily controlled in case of narrowband CW radar by an appropriate passive microwave design, it becomes much more complicated in case of stepped-frequency CW and frequency-modulated CW architectures that present an ultra-wideband nature. In this paper, a monostatic CW radar integrating a tunable wideband leakage canceler aiming at indoor tagless localization is presented and discussed. The use of the feedforward canceler allows a strong reduction of the unwanted leakage over the whole radar bandwidth. Experimental results demonstrate the feasibility of this approach, showing an outstanding improvement of the radar dynamic range.

scholarly journals A Local Oscillator Phase Compensation Technique for Ultra-Wideband Stepped-Frequency Continuous Wave Radar Based on a Low-Cost Software-Defined Radio

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 780
Author(s):  
Kazunori Takahashi ◽  
Takashi Miwa
Keyword(s):  
Software Defined Radio ◽  
Initial Phase ◽  
Continuous Wave ◽  
Low Cost ◽  
Local Oscillator ◽  
The Other ◽  
Ultra Wideband ◽  
Single Frequency ◽  
Wave Radar ◽  
Stepped Frequency

The paper discusses a way to configure a stepped-frequency continuous wave (SFCW) radar using a low-cost software-defined radio (SDR). The most of high-end SDRs offer multiple transmitter (TX) and receiver (RX) channels, one of which can be used as the reference channel for compensating the initial phases of TX and RX local oscillator (LO) signals. It is same as how commercial vector network analyzers (VNAs) compensate for the LO initial phase. These SDRs can thus acquire phase-coherent in-phase and quadrature (I/Q) data without additional components and an SFCW radar can be easily configured. On the other hand, low-cost SDRs typically have only one transmitter and receiver. Therefore, the LO initial phase has to be compensated and the phases of the received I/Q signals have to be retrieved, preferably without employing an additional receiver and components to retain the system low-cost and simple. The present paper illustrates that the difference between the phases of TX and RX LO signals varies when the LO frequency is changed because of the timing of the commencement of the mixing. The paper then proposes a technique to compensate for the LO initial phases using the internal RF loopback of the transceiver chip and to reconstruct a pulse, which requires two streaming: one for the device under test (DUT) channel and the other for the internal RF loopback channel. The effect of the LO initial phase and the proposed method for the compensation are demonstrated by experiments at a single frequency and sweeping frequency, respectively. The results show that the proposed method can compensate for the LO initial phases and ultra-wideband (UWB) pulses can be reconstructed correctly from the data sampled by a low-cost SDR.

scholarly journals A low-noise photonic heterodyne synthesizer and its application to millimeter-wave radar

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eric A. Kittlaus ◽  
Danny Eliyahu ◽  
Setareh Ganji ◽  
Skip Williams ◽  
Andrey B. Matsko ◽  
...  
Keyword(s):  
Phase Noise ◽  
Millimeter Wave ◽  
Continuous Wave ◽  
Dynamic Range ◽  
Wave Generation ◽  
Low Noise ◽  
Ultra Wideband ◽  
Optical Systems ◽  
Thz Spectroscopy ◽  
Wave Radar

AbstractMicrowave photonics offers transformative capabilities for ultra-wideband electronic signal processing and frequency synthesis with record-low phase noise levels. Despite the intrinsic bandwidth of optical systems operating at ~200 THz carrier frequencies, many schemes for high-performance photonics-based microwave generation lack broadband tunability, and experience tradeoffs between noise level, complexity, and frequency. An alternative approach uses direct frequency down-mixing of two tunable semiconductor lasers on a fast photodiode. This form of optical heterodyning is frequency-agile, but experimental realizations have been hindered by the relatively high noise of free-running lasers. Here, we demonstrate a heterodyne synthesizer based on ultralow-noise self-injection-locked lasers, enabling highly-coherent, photonics-based microwave and millimeter-wave generation. Continuously-tunable operation is realized from 1-104 GHz, with constant phase noise of -109 dBc/Hz at 100 kHz offset from carrier. To explore its practical utility, we leverage this photonic source as the local oscillator within a 95-GHz frequency-modulated continuous wave (FMCW) radar. Through field testing, we observe dramatic reduction in phase-noise-related Doppler and ranging artifacts as compared to the radar’s existing electronic synthesizer. These results establish strong potential for coherent heterodyne millimeter-wave generation, opening the door to a variety of future applications including high-dynamic range remote sensing, wideband wireless communications, and THz spectroscopy.

scholarly journals Analysis of the Snow Water Equivalent at the AEMet-Formigal Field Laboratory (Spanish Pyrenees) During the 2019/2020 Winter Season Using a Stepped-Frequency Continuous Wave Radar (SFCW)

2021 ◽  
Vol 13 (4) ◽  
pp. 616
Author(s):  
Rafael Alonso ◽  
José María García del Pozo ◽  
Samuel T. Buisán ◽  
José Adolfo Álvarez
Keyword(s):  
Software Defined Radio ◽  
Continuous Wave ◽  
Snow Water Equivalent ◽  
Cosmic Ray ◽  
Relative Dielectric Permittivity ◽  
Near Surface ◽  
Wave Radar ◽  
Spanish Pyrenees ◽  
Snow Water ◽  
Stepped Frequency

Snow makes a great contribution to the hydrological cycle in cold regions. The parameter to characterize available the water from the snow cover is the well-known snow water equivalent (SWE). This paper presents a near-surface-based radar for determining the SWE from the measured complex spectral reflectance of the snowpack. The method is based in a stepped-frequency continuous wave radar (SFCW), implemented in a coherent software defined radio (SDR), in the range from 150 MHz to 6 GHz. An electromagnetic model to solve the electromagnetic reflectance of a snowpack, including the frequency and wetness dependence of the complex relative dielectric permittivity of snow layers, is shown. Using the previous model, an approximated method to calculate the SWE is proposed. The results are presented and compared with those provided by a cosmic-ray neutron SWE gauge over the 2019–2020 winter in the experimental AEMet Formigal-Sarrios test site. This experimental field is located in the Spanish Pyrenees at an elevation of 1800 m a.s.l. The results suggest the viability of the approximate method. Finally, the feasibility of an auxiliary snow height measurement sensor based on a 120 GHz frequency modulated continuous wave (FMCW) radar sensor, is shown.

scholarly journals A 1.5–40 GHz frequency modulated continuous wave radar receiver front-end

2021 ◽  
pp. 1-11
Author(s):  
Mantas Sakalas ◽  
Niko Joram ◽  
Frank Ellinger
Keyword(s):  
Continuous Wave ◽  
Noise Figure ◽  
Supply Voltage ◽  
Low Noise ◽  
Ultra Wideband ◽  
Front End ◽  
Wave Radar ◽  
Bicmos Technology ◽  
Circuit Components ◽  
High Band

Abstract This study presents an ultra-wideband receiver front-end, designed for a reconfigurable frequency modulated continuous wave radar in a 130 nm SiGe BiCMOS technology. A variety of innovative circuit components and design techniques were employed to achieve the ultra-wide bandwidth, low noise figure (NF), good linearity, and circuit ruggedness to high input power levels. The designed front-end is capable of achieving 1.5–40 GHz bandwidth, 30 dB conversion gain, a double sideband NF of 6–10.7 dB, input return loss better than 7.5 dB and an input referred 1 dB compression point of −23 dBm. The front-end withstands continuous wave power levels of at least 25 and 20 dBm at low band and high band inputs respectively. At 3 V supply voltage, the DC power consumption amounts to 302 mW when the low band is active and 352 mW for the high band case, whereas the total IC size is $3.08\, {\rm nm{^2}}$ .

scholarly journals A Novel Method for Breath Detection via Stepped-Frequency Continuous Wave Ultra-Wideband (SFCW UWB) Radars Based on Operational Bandwidth Segmentation

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3873 ◽  
Author(s):  
Hao Lv ◽  
Teng Jiao ◽  
Yang Zhang ◽  
Fulai Liang ◽  
Fugui Qi ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Ultra Wideband ◽  
Time Dimension ◽  
Processing Scheme ◽  
Practical Applications ◽  
Uwb Radar ◽  
Operational Frequency ◽  
Stepped Frequency ◽  
Breath Detection

Human being detection via ultra-wideband (UWB) radars has shown great prospects in many areas, such as biomedicine, military operation, public security, emergency rescue, and so on. When a person stays stationary, the main feature that separates him/her from surroundings is the movement of chest wall due to breath. There have been many algorithms developed for breath detection while using UWB radars. However, those algorithms were almost based on a basic scheme that focused on processing in the time dimension of UWB data. They did not utilize the benefits from the wide operational bandwidth of UWB radars to show potential superiority over those narrowband systems such as a continuous wave (CW) Doppler radar. In this paper, a breath detection method was proposed based on operational bandwidth segmentation. A basic theoretical model was firstly introduced, indicating that characteristics of breath signals contained in UWB echoes were consistent among the operational frequencies, while those of clutters were not. So, the method divided a set of UWB echo data into a number of subsets, each of which corresponded to a sub-band within the operational bandwidth of the UWB radar. Thus information about the operational frequency is provided for subsequent processing. With the aid of the information, a breath enhancement algorithm was developed mainly by averaging the segmented UWB data along the operational frequency. The algorithm’s performance was verified by data measured by a stepped-frequency CW (SFCW) UWB radar. The experimental results showed that the algorithm performed better than that without the segmentation. They also showed its feasibility for fast detection of breath based on a short duration of data. Moreover, the method’s potential for target identification and impulse-radio (IR) UWB radar was investigated. In summary, the method provides a new processing scheme for UWB radars when they are used for breath detection. With this scheme, the UWB radars have a benefit of greater flexibility in data processing over those narrowband radars, and thus will perform more effectively and efficiently in practical applications.

Accuracy Analysis of Positioning Method for Fusion GPS Pseudo-Range and Continuous Wave Radar

2013 ◽  
Vol 756-759 ◽  
pp. 354-360
Author(s):  
Hui Juan Zhang ◽  
Chao Wei
Keyword(s):  
Continuous Wave ◽  
Calculated Data ◽  
Wave Radar ◽  
Global Positioning ◽  
Positioning Method ◽  
Measurement Principle ◽  
Trajectory Measurement ◽  
The Impact ◽  
Cw Radar ◽  
Range Test

Continuous wave (CW) radar and global positioning system (GPS) is the main equipment of trajectory measurement in range. Based on range test background, propose a method to fuse GPS pseudo-range and CW radar range to provide complete trajectory positioning parameters, effectively reduce the impact of the systematic error of the measuring element to improve positioning precision of aircraft orbit solving. Through research on the measurement principle and the practice calculated data is given in this paper. Finally, several famous practical examples and simulation results are presented to illustrate our method efficiently.

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