A Compact Single/Dual-Polarized Broadband Antenna With SUM and Difference Beam Capabilities

A novel compact single/dual linearly polarized antenna with broadband and SUM and Difference Beam capabilities is developed in this letter. An electromagnetic simulated model for its radiation element, together with its dual-mode feed network and antenna bracket, is proposed and verified by measurement. The operation band of the realized antenna is 0.96-1.78 GHz, with 10-dB return loss bandwidth of over 55%. As it operates at Mode 1, its dual linearly polarized port isolation is over 30 dB, and 3-dB gain beamwidth is 42° at 1.25 GHz, with gain of 7.6 dB obtained. The gain difference between Modes 1 and 2 is about 7 dB at 1.25 GHz within the angle of -15° ≤ θ ≤ 15° for the same polarization. The measured radiation patterns agree well with the simulated ones. The whole antenna is very compact in geometry, and its size is only about 155 mm in diameter and 47 mm in height.