High-isolation wideband single-pole double-throw (SPDT) transmitter/receiver (T/R) switch with PIN diode for wireless communication applications

The FCC´s allocation of 300 MHz of bandwidth in the 5-GHz frequency band (5.15-5.35/5.725-5.825 GHz) for the unlicensed national information infrastructure (UNII), high data rate (up to 50 Mb/s) wireless local area networks (WLAN) have become increasingly popular and important for mobile computing devices such as notebook computers. The European counterpart is the HIPERLAN (High Performance Radio LAN) system, which also operates in the 5-GHz band (5.15-5.35/5.47-5.725 GHz). In order to meet the potentially high demand for such wireless LAN products, low-cost radio transceiver front-ends capable of performing at 5.15-5.825 GHz are essential. In this paper, a compact wideband SPDT-T/R switch with PIN diode and triangular microstrip antenna have been introduced, analyzed and designed. The proposed SPDT will produce high isolation when the PIN diodes are turned `OFF´. The simulated and experimental results of the proposed structures are presented to demonstrate the performance.