Parallel plate mode suppressed strip-line fed antenna for CP phased array antenna

A parallel plate mode (PPM) suppressed strip-line fed antenna with a via-wall is proposed for circular polarization phased array antenna system. By introducing a metal cavity using a via-wall around antenna, radiation characteristic perturbation and mutual coupling are improved. To verify the PPM suppression effects, conventional antenna, which does not have via-walls, and the proposed antenna are compared in 4×4 array configuration. The reflection coefficient variation is reduced and the mutual coupling is improved about 17 dB. The measured antenna gain is 7.05 dBi, and axial ratio is 1.2 dB at designed frequency 9.5 GHz.