scholarly journals Design and validation tests for compact FMCW C-band Analog-Front-End for radar imaging applications

2016 ◽  
Vol 8 (6) ◽  
pp. 845-854
Author(s):  
Damian Gromek ◽  
Piotr Samczyński ◽  
Maciej Wielgo ◽  
Mateusz Malanowski ◽  
Krzysztof Kulpa

This paper presents the design, implementation, and validation tests of a C-band analog-front-end (AFE) for the frequency modulated continuous wave (FMCW) radar. The system was designed to be used in various radar applications, including short rage mode, synthetic aperture radar (SAR) and moving target indication (MTI) mode. The AFE presented here was based on commercial off-the-shelf radio frequency components, and designed as a homodyne system, so the final applications were based on the FMCW radar. Validation tests and experiments were carried out in the laboratory and in open-air environments. The authors present tests of the AFE, including MTI and SAR trials, conducted using a ground moving platform (a car) and an airborne platform (a small aircraft). The results are discussed with the prospect of future work and further improvements in mind.

Author(s):  
K. Ndini ◽  
D. Gromek ◽  
M. Wielgo ◽  
P. Samczynski ◽  
M. Malanowski

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1047
Author(s):  
Lorenzo Capineri ◽  
Andrea Bulletti

Continuous monitoring of mechanical impacts is one of the goals of modern SHM systems using a sensor network installed on a structure. For the evaluation of the impact position, there are generally applied triangulation techniques based on the estimation of the differential time of arrival (DToA). The signals generated by impacts are multimodal, dispersive Lamb waves propagating in the plate-like structure. Symmetrical S0 and antisymmetrical A0 Lamb waves are both generated by impact events with different velocities and energies. The discrimination of these two modes is an advantage for impact positioning and characterization. The faster S0 is less influenced by multiple path signal overlapping and is also less dispersive, but its amplitude is generally 40–80 dB lower than the amplitude of the A0 mode. The latter has an amplitude related to the impact energy, while S0 amplitude is related to the impact velocity and has higher frequency spectral content. For these reasons, the analog front-end (AFE) design is crucial to preserve the information of the impact event, and at the same time, the overall signal chain must be optimized. Large dynamic range ADCs with high resolution (at least 12-bit) are generally required for processing these signals to retrieve the DToA information found in the full signal spectrum, typically from 20 kHz to 500 kHz. A solution explored in this work is the design of a versatile analog front-end capable of matching the different types of piezoelectric sensors used for impact monitoring (piezoceramic, piezocomposite or piezopolymer) in a sensor node. The analog front-end interface has a programmable attenuator and three selectable configurations with different gain and bandwidth to optimize the signal-to-noise ratio and distortion of the selected Lamb wave mode. This interface is realized as a module compatible with the I/O of a 16 channels real-time electronic system for SHM previously developed by the authors. High-frequency components up to 270 kHz and lower-frequency components of the received signals are separated by different channels and generate high signal-to-noise ratio signals that can be easily treated by digital signal processing using a single central unit board with ADC and FPGA.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2758
Author(s):  
Hyunmin Jeong ◽  
Sangkil Kim

This paper presents an educational low-cost C-band frequency-modulated continuous wave (FMCW) radar system for use in indoor through-wall metal detection. Indoor remote-sensing applications, such as through-wall detection and positioning, are essential for the comprehensive realization of the internet of things or super-connected societies. The proposed system comprises a two-stage radio-frequency power amplifier, a voltage-controlled oscillator, circuits for frequency modulation and system synchronization, a mixer, a 3-dB power divider, a low-noise amplifier, and two cylindrical horn antennas (Tx/Rx antennas). The antenna yields gain values in the 6.8~7.8 range when operating in the 5.83~5.94 GHz frequency band. The backscattered Tx signal is sampled at 4.5 kHz using the Arduino UNO analog-to-digital converter. Thereafter, the sampled signal is transferred to the MATLAB platform and analyzed using a customized FMCW radar algorithm. The proposed system is built using commercial off-the-shelf components, and it can detect targets within a 56.3 m radius in indoor environments. In this study, the system could successfully detect targets through a 4 cm-thick ply board with a measurement accuracy of less than 10 cm.


2010 ◽  
Vol 8 ◽  
pp. 7-11 ◽  
Author(s):  
M. Vogt ◽  
M. Gerding ◽  
T. Musch

Abstract. In industrial process measurement instrumentation, radar systems are well established for the measurement of filling levels of liquids in tanks. Level measurements of bulk goods in silos, on the other hand, are more challenging because the material is heaped up and its surface has typically a relatively complex shape. In this paper, the application of synthetic aperture radar (SAR) reconstruction with a frequency modulated continuous wave (FMCW) radar system for level measurements of bulk goods is evaluated. In the proposed monostatic setup, echo signals are acquired at discrete antenna positions on top of the silo. Spatially resolved information about the surface contour of a bulk good heap is reconstructed by coherent 'delay and sum' processing. The concept has been experimentally evaluated with a 24 to 26 GHz FMCW radar system mounted on a linear stepping motor positioning unit. Measurements on a thin metal wire at different range and on a curved test-object with a diffusely scattering surface have been performed to analyze the system's point spread function (PSF) and performance. Constant range and azimuth resolutions (−6 dB) of 15 cm and 8 cm, respectively, have been obtained up to a range of 6 m, and results of further evaluations show that the proposed concept allows more accurate and reliable level reconstructions of surface profiles compared to the conventional approach with measurements at a single antenna position.


2013 ◽  
Vol 59 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Janusz S. Kulpa ◽  
Mateusz Malanowski ◽  
Damian Gromek ◽  
Piotr Samczyńsk ◽  
Krzysztof Kulpa ◽  
...  

Abstract In the paper experimental results of ISAR (Inverse Synthetic Aperture Radar) processing obtained with highresolution radar are presented. Targets under observation were ground moving vehicles, such as cars, trucks and tractors. The experiments were performed with a FMCW (Frequency- Modulated Continuous-Wave) radar operating at 94 GHz with almost 1 GHz of bandwidth. Due to the measurement scenario more typical for SAR (Synthetic Aperture Radar), than ISAR, i.e. targets moving along straight line crossing the antenna beam, algorithms usually applied for SAR processing have been used.


Author(s):  
Raja Krishnamoorthy ◽  
E. Kavitha ◽  
V. Beslin Geo ◽  
K.S.R. Radhika ◽  
C. Bharatiraja

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