Fig 18 - uploaded by Ram M. Narayanan
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One of the latest challenges being investigated by the US Army Research Laboratory’s (ARL) Electronics and Radio Frequency (E&RF) Division is the development of a radar system that can accurately detect and range an electronically nonlinear target, such as a detonator of an improvised explosive device (IED). Previous nonlinear radar systems detect...
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... distance calculated from the phase data is well within 5% of the actual distance (24 ft), confirming that using harmonic phase information to determine range is a valid technique for use in nonlinear radar. Figure 18 shows the next experimental design used to validate the harmonic phase response, a wireless setup slightly more complex than the wired system previously discussed. Like the wireline tests, this experimental design uses the Keysight NVNA to generate the series of transmit signals, as well as receive the harmonic response; though in this wireless configuration, the received signal enters Port 2, instead of returning to the same port, Port 1, as in the previous design. Similar to the wireline tests, the transmission chain begins with signal generation, amplification, and low pass filtering; however, the wireless configuration employs a much more ...
Citations
A new method to classify electronic devices using a Frequency-Swept Harmonic Radar (FSHR) approach is proposed in this paper. The FSHR approach enables us to utilize the frequency diversity of the harmonic responses of the electronic circuits. Unlike previous studies, a frequency-swept signal with a constant power is transmitted to Electronic Circuits Under Test (ECUTs). The harmonic response to a frequency-swept transmitted signal is found to be distinguishable for different types of ECUTs. Statistical and Fourier features of the harmonic responses are derived for classification. Later, the harmonic characteristics of the ECUTs are depicted in 3D harmonic and feature spaces for classification. Three-dimensional harmonic and feature spaces are composed of the first three harmonics of the re-radiated signal and the statistical or Fourier features, respectively. We extensively evaluate the performance of our novel method through Monte Carlo simulations in the presence of noise.
A novel approach for classification of electronic devices using harmonic radar is proposed in this paper. We transmit single-tone time-varying signals with varying power to the electronic circuits under test (ECUT). The novelty of proposed approach stems from representing the harmonic response of ECUT in the harmonic and statistical feature spaces. Besides, as a new approach, we sweep the transmitting power to capture the nonlinear behavior relevant to nonlinear I-V characteristics of ECUT. Furthermore, we utilize both time and frequency content of the received harmonic response. Statistical and Fourier domain features of the received power levels at harmonic frequencies are determined and used for classification. K-Nearest Neighbors (kNN) is chosen as the classification method. We demonstrate the effectiveness of our method in the presence of noise through Monte Carlo simulations with different signal-to-noise ratio (SNR) values. Extensive simulation studies show that our new approach of power-swept signals and new features we have developed are very effective at classifying nonlinear devices.
