A Wideband Compact Dual-Polarized Microstrip Patch Antenna under Triple-Resonance

A low-profile compact wideband differential-fed dual-polarized microstrip patch antenna (MPA) under triple-resonance is proposed. Firstly, a differential feeding scheme is selected to suppress even-order modes and effectively reduce the cross-polarization level of the antenna. Next, an array of shorting pins are loaded underneath the patch. Their main target is to resonate the antenna in two resonant modes. After that, an additional resonant mode is excited by using two pairs of L-shaped probes. Moreover, four slots and a cross slot are etched on the radiating patch. With these arrangements, two resonant modes of the MPA and an additional resonant mode are moved closely to each other, thus effectively extending its impedance bandwidth to about 23.6%. Meanwhile, it still keeps a low-profile property of about 0.029 lambda(0) (lambda(0) is the free space wavelength). Additionally, the isolation between these differential-fed reaches to about 60 dB and the size of the antenna is reduced from 1.0 lambda(0) x1.0 lambda(0) to 0.8 lambda(0) x0.8 lambda(0) by etching four slots.