A Wideband PSP Antenna Radiating a Linearly Polarized Conical Beam

This paper presents a PSP (patch with a ring slot and conducting pins) antenna. Using the FDTD method, the PSP antenna is designed to radiate a linearly polarized conical beam over a wide frequency range. The design is performed in three steps. In the first step, a center-fed patch above a ground plate, referred to as the original patch, is analyzed. It is found that the reactive component of the input impedance of the original patch is large. In the second step, the high input reactance is reduced by cutting a ring slot into the original patch. The patch with the ring slot is referred to as the P-slot. In the third step, the P-slot is fine-tuned using four conducting pins, which are short-circuited to the ground plate. The analysis of the P-slot with conducting pins, i.e., the PSP antenna, reveals that it has a wide VSWR frequency characteristic; a VSWR bandwidth of approximately 37% is obtained. Within this VSWR bandwidth, the PSP antenna forms a conical radiation pattern E_thetas, where the cross-polarization component E_phi does not appear down to -30 dB, as desired