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The paper reports on a new fully-polarimetric instrumentation radar operating at 228 GHz. The radar is designed to operate in FMCW mode and enjoys high angular and range resolutions and fast data acquisition.
The radar's antenna usually determines the total size and weight of the radar since in most applications a narrow beam is required. Reduction in antenna size can be achieved without compromising its beam performance if its operating frequency were to be increased proportionally. Hence, if higher operating frequency is selected for a given radar application, then a smaller antenna can be designed,...
This paper examines recently measured polarimetric radar backscatter data of different types of bare and vegetation-covered surfaces at 222 GHz. Bare surfaces, such as asphalt, dirt, and concrete, are electrically rough with aggregate sizes comparable to the wavelength. This results in substantial volume and surface scattering. The data show strong angular dependence of the backscatter response from...
Monte Carlo simulations are performed numerically to characterize the behavior of both the forward and backward scattered fields for a millimeter source different rain media. Especial attention is given to long-distance wave propagation in such media. Numerical simulations are performed at high millimeter-wave frequencies using distorted Born approximation in conjunction with single scattering for...
The fact that millimeter-wave radars can be designed to be compact in size and light in weight, while at the same time be broadband and narrow beam systems, have led to a proliferation of these radars over a wide range of applications. These applications include high resolution synthetic aperture radar imaging, target surveillance and tracking, vehicle collision avoidance, autonomous navigation of...
Characterization of different thin materials at millimeter-wave frequency, 240 GHz, is presented. This includes vegetation leaves as well as different types of fabrics. The complex permittivity retrieval algorithm is based on fitting the measured transmission coefficient at different incident angles to the corresponding analytical transmission coefficient of a simple dielectric slab. The extracted...
This paper examines recently acquired polarimetric data of dry sand with smooth air/sand interface at MMW frequencies. The data characterizes volume scattering from different types of sand as a function of the radar incidence angle, frequency, polarization, and particle size. The data shows substantial volumetric response from dry sand at MMW frequencies with significant depolarization (between −12...
This paper presents a new approach for designing frequency agile, coherent radars with programmable waveform spectrum. The new approach permits the adjustment of the transmitted signal's central frequency, bandwidth, and modulation by the user while at the same time ensuring that the received signal is always detected at baseband.
This paper presents the design of a new compact, low-cost, FMCW millimeter-wave radar for high-resolution, short-range imaging applications. In this design, problems that have limited the performance of classical FMCW radars were solved. A W-band FMCW radar with better than 0.3 m range resolution, 1° beamwidth, 25 kHz chirp rate, 19 dBm output power, and operating in real-time, was constructed and...
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