접지면 슬롯의 섭동을 이용한 편파변환 마이크로스트립 안테나

Abstract

In this paper, a new microstrip antenna using perturbations in square slotted ground is proposed for a switchable polarizations sense. The proposed antenna can radiate a circular polarization(CP) wave due to the orthogonal E-field distribution on the square perturbation slot. To realize the switchable condition, the proposed antenna is equipped with four PIN diodes for two different bias conditions of ON/OFF states. As a result, the designed antenna can generate the right-handed(RH) CP, the left-handed(LH) CP, and the linear polarization(LP) which depend on the bias conditions. At the operating frequency of 2.475GHz with the RHCP, the axial ratio(AR) was about 1.8dB and the 3-dB AR bandwidth was 34MHz which is about 1.4% fractional bandwidth. For the LHCP at the operating frequency of 2.47GHz, the AR was about 1.2dB and the 3-dB AR bandwidth was 36 MHz which is the fractional bandwidth of about 1.5%. For the LP, the voltage- standing wave ratio(VSWR) bandwidth and the gain were up to 77MHz and 2dBi at 2.44GHz, respectively. The radiation patterns are also presented with low cross polarization levels.