Dual-Band Differential Shifted-Feed Microstrip Grid Array Antenna With Two Parasitic Patches

A dual-band differential shifted-feed microstrip grid array antenna (DSF-MGAA) with two parasitic patches is presented in this communication. By moving the feed location, a conventional MGAA (C-MGAA) can be turned into an SF-MGAA for dual-band operation. The high-frequency band of SF-MGAA corresponds to the operation mode of the C-MGAA, and its low-frequency band is similar to that of the patch or meshed patch antenna. A new differential feeding scheme and two parasitic patches are adopted to improve the impedance bandwidth of SF-MGAA. The proposed DSF-MGAA can cover a dual band of 3.7 and 28.5 GHz. The measured -10 dB impedance bandwidths of 3.4% and 4.5%, which correspond to the peak gains of 8.98 and 19.2 dBi, are obtained in the low- and high-frequency bands, respectively. The DSF-MGAA can be a potential candidate for the future dual-band wireless communication.