K-band Low-Sidelobe Transceiving Antennas for Radar Detection

Abstract

This paper presents a novel design of K-band low-sidelobe transceiving antenna arrays for radar detection. Based on the framework of K-band radar sensor, an 8×6 series-fed microstrip comb array with slim comb-line structures is employed as transmitting antenna, while another two identical 8×2 arrays are employed as receiving antennas. For purpose of enhancing radar detection precision and anti-interference capability, a very low sidelobe level (SLL) of transceiving antennas is necessary. Therefore, Chebyshev distribution is used for tapered amplitude excitation of antenna elements for high siedelobe suppression. In conventional design, the amplitude tapering of elements is usually adjusted by the comb-line width, which is effective only when the difference is moderate, otherwise the radiation characteristic of each element would vary obviously and the synthesized radiation pattern would deteriorate. In this work, a combined method of amplitude tapering adjustment of elements by varying both comb-line and feedline widths is proposed. According to the simulation, the SLLs of 8×6 transmitting antenna are -32.3/-33 dB in E/H-planes, whose broadside gain is 19.48 dBi. While the SLLs of two 8×2 receiving antennas are -34.7/-35.1 dB in E-planes, whose broadside gains are 14.37/14.43 dBi, respectively. The simulated results indicate an excellent antenna performance with very low SLLs and gains.