Low-Profile Dual-Band Microstrip Patch Antenna With Shorting Pins

A single-layer low-profile dual-band patch antenna is proposed in this letter. A.-shaped slot is engraved on the radiating patch, separating it into a main patch and a parasitic patch to achieve the dual-band characteristics. The purpose of loading five shorting pins between the two vertical slots on the main patch is to turn down the two frequencies, which can generate TM01 mode and TM11 mode. To improve the impedance matching in the lower band and broaden the dual-band bandwidth, four shorting pins are placed on the edge of the long side of the parasitic patch, which can excite the TM (10) mode. The combination of the TM (0)1, TM (11), and TM (10) modes achieves the 3.45-3.7 GHz and 4.7-5.33 GHz dual band. Manufacturing and measuring a prototype. The results of the measurements indicate that the antenna achieves a dualband with reflection coefficient less than -6 dB, which are 3.5-3.75 GHz (250 MHz, 7.0%) and 4.73-5.41 GHz (680 MHz, 13.4%) with peak gains of 6.23 and 5.06 dB in the low and high bands, respectively. The average total efficiencies in the dual bands are 64.2% and 77.3%, respectively.