Design and experimental characterization of a surface with low radar cross-section at millimeter-wave frequencies

Abstract

The investigation of low radar cross-section (RCS) structures is of great practical interest for the car integration of radar systems. This paper presents for the first time the study of a low-RCS surface at millimeter wave frequencies. The surface employs a chessboard-like geometry that uses a periodic displacement of artificial magnetic conductors (AMCs) and perfect electric conductors (PECs). The structure is able to redirect the incident wave in non-specular directions, and it is thus possible to achieve a significant reduction of the RCS in the boresight direction. The measurement results confirm the predictions of the full-wave simulations, and they prove that the proposed surface can effectively achieve more than 17 dB of RCS reduction in the case of normal incidence at 76.8 GHz.

Reducing the Radar Cross Section of Microstrip Arrays Using AMC Structures for the Vehicle Integration of Automotive Radars

“…To fully understand the basic principle of the proposed design it is convenient to briefly describe the chessboardlike low-RCS surface, which is the starting point for the development of the low-RCS antenna. For a full description of the low-RCS surfaces we suggest to refer to [7]- [9].…”

“…The backscattering has been measured with a 25-dBi-standard gain horn antenna placed 2 m apart from the array. The measurement setup is similar to that one described in [9], and for brevity it is here omitted.…”

“…To collect only the signal of interest backscattered by the AUT, the time gating has been applied with a 30 GHz frequency span. For a detailed description of the measurement setup settings, we suggest to refer to [9].…”

“…This surface can achieve a significant RCS reduction compared to an equal-size metal plate. More recently, the effectiveness of this solution has been verified at mm-wave frequencies, too [9]. The basic principle of the low-RCS chessboard surface is the mutual phase compensation of the wave reflected by the AMC and the PEC, that permits to achieve destructive interference, and therefore a reduction of the backscattered wave in a specific direction and at a given frequency.…”

A Complex Low-RCS Antenna System for the Placement of mm-Wave Automotive Radars behind Car Bumpers

“…The investigation of possible techniques to mitigate the multiple reflections between the radar and the car fascia is thus of great practical interest. Some previous works [5], [6] explained that a possible approach to reduce the multiple reflections can be the design of a radar sensor with low-RCS, i.e. to develop a sensor that scatters less power back in boresight direction when it is illuminated by an impinging wave.…”