Improved model of the circularly polarized patch antenna array at 24 GHz for radar applications

Abstract

The paper presents the improved design of the novel circularly polarized patch antenna array operating at ISM band 24.05-24.25 GHz. The antenna array consists of 24 identical truncated patches which are serially fed through the microstrip line. The antenna is a travelling-wave array with exponential power distribution which provides very good side lobe suppression of 30 dB in the entire operating band making it suitable for automotive radar applications. Simulated axial ratio is below 3dB in the range (24.06-24.26) GHz, the antenna gain is greater than 17.2 dBi, cross polarization is better than 15 dB and return loss is greater than 15 dB in the entire ISM band.Index Terms -Antenna array, circularly polarized patch antenna, exponential power distribution, axial ratio.