CAD of 0.1- to 10-GHz GaAs MMIC SPST switch

摘要

Abstract: The design of the SPST switch provides an insertion loss less than 2 dB, isolation more than 40 dB and return loss better than 17.5 dB in the frequency range of 0.1 GHz to 10 GHz. The insertion loss is improved by treating SPST switch as a 50 approximately ega artificial transmission line with incorporation of inductor in series arm and the capacitance of MESFET in the shunt arm. High isolation is ensured by the lower value of `ON' resistance of MESFET in shunt arm. Also good return loss is achieved by paralleling a 50 approximately ega resistor with capacitance of MESFET in series arm. The absence of DC blocking capacitors and replacement of large value bias chokes with 5 K approximately ega resistors effectively improved the performance of SPST switch at low frequency and also reduced the chip size. The overall chip dimension is 2.2 mm $MUL 1.7 mm.!2