Compact differential-fed dual-band antenna via loading shorting pin

This article presents the design of a differential-fed dual-band antenna for wireless sensor network applications. A novel method is applied to enhance the bandwidth of a differential-fed square patch antenna by loading shorting pin. Initially, a differential-fed square patch antenna is introduced to generate the odd-modes, that is, TM10, TM12 and TM30. Subsequently, with the adoption of a shorting pin, TM30 mode can be adjusted in proximity to TM12 mode for a dual resonance. At the same time, there is no effect on TM10 mode. A prototype antenna is fabricated and experimentally measured to verify the proposed method. Measured results show that the impedance bandwidth of the proposed antenna at the higher frequency band can cover from 5.11 GHz to 5.69 GHz while the lower frequency band operates from 3.35 GHz to 3.43 GHz.