Design of a Novel K-band Broadband Circularly Polarized Micro-Strip Antenna Array

Abstract

A K-band broadband circularly polarized antenna array is proposed in this paper. The antenna unit is a multiple-layer microstrip antenna, which is fed by H-type / U-type gaps coupling. It can realize the characteristics of broadband, circular polarization, small volume, light weight and high radiation efficiency. Based on this unit, an $8\times 8$ antenna array, which has the characteristics of high gain, low side-lobe, low profile, beam-scanning, is finally designed and fabricated. Within the bandwidth of $\mathrm{f}0\pm 2\text{GHz}$, the VSWR of the array antenna is no more than 1.8. At the center frequency point f0, the gain of the antenna array is greater than 22dB, the 3dB beam width can reach 13 °, and the side-lobe level is less than −14dB., which is very suitable for communication equipment of space-based measurement and control system.