Wideband Dual-Polarized Differential-Fed Filtering Microstrip Patch Antenna with High Suppression and Wide Stopband

This paper presents a wideband dual-polarized filtering antenna with high suppression level and wide stopband. In the proposed antenna, driven patch operates in TM10 mode an inherent radiation null caused by higher TM12. Four dual-strip structures connected feeding probes are placed below to achieve capacitive coupling, thus resulting low-frequency sharp roll-off rate. The introduction of parasitic strips generates in-band resonance two high-frequency nulls, which widens upper slots etched on excite third resonance, achieving operation band. prototype is fabricated. With four controllable out-of-band levels above 29 dB band greater than 1 GHz 21 up 7 GHz, respectively. Due three resonances, impedance bandwidth 2.93-3.96 fractional 30% obtained. rotational symmetry structure differential probes, has cross-polarization ratio better 28 dB, polarization isolation 43 good peak gain about 9.9 dBi.