GAIN AND BANDWIDTH ENHANCEMENT OF CIRCULARLY POLARIZED MSA USING PRS AND AMC LAYERS

In this paper, a circularly polarized (CP), high gain and wide bandwidth metal plated microstrip antenna (MSA) using partially reflecting surface (PRS) and artificial magnetic conductor (AMC) layers is proposed. The bandwidth of MSA is increased primarily, using AMC layers, and gain is increased by placing the antenna in a Fabry-Perot cavity (FPC) resonator. The two slotted AMCs are designed to resonate at two frequencies which electromagnetically couple to provide wide bandwidth. The FPC antenna with PRS and AMC layers provides higher gain, more impedance bandwidth, less gain variation and more miniaturization than the antenna without AMC layers. The proposed antenna provides S11 < −10 dB, axial ratio (AR) < 3 dB and 17.4 dBi peak gain with gain variation < 3 dB over 5.725GHz to 6.4GHz frequency band. Broadside radiation patterns have side lobe level (SLL) < −20 dB, cross polarization (CPL) < −16 dB and front to back (F/B) lobe ratio > 20 dB. The overall antenna dimensions are 2.83λ0 × 3.23λ0 × 0.49λ0, where λ0 is the free space wavelength corresponding to the central frequency of 5.725–6.4GHz. The proposed structure is fabricated, and the measured results agree with simulation ones.