High isolation 1-20 GHz MMIC switches with on-chip drivers

Abstract

The design, fabrication, and performance of monolithic microwave integrated circuit single-pole single-throw (MMIC SPST) and single-pole double-throw (SPDT) switches with on-chip transistor-transistor logic (TTL) compatible drivers is presented. Both switch types cover 1-20 GHz, operate from a single +10 to +12 V power supply and commute in less than 15 ns. Both have at least -12 dB return loss at all ports and handle +22 dBm signal levels. The SPST switch has an insertion loss of 2.5 dB and >50 dB isolation. The SPDT switch's insertion loss is 2.7 dB with 49 dB isolation. The switches require only external DC blocking capacitors to set the lower end of their useful bandwidth. The excellent isolation achieved by these switches is principally attributable to the design of the series and shunt FETs used in their realization.<>