Comparison of GaAs MESFET and GaAs p-i-n diodes as switch elements

The Kurokawa-Schlosser quality factor Q̂ is used to compare the GaAs MESFET switch with the GaAs p-i-n diode switch. The MESFET device parameters are governed by the power handling capability and the specified pinchoff voltage, and the switch Q̂ is calculated from an approximate expression. The GaAs p-i-n has been characterized using a simple diode model which is derived from detailed simulations. The comparison for typical devices shows that the GaAs pin has the higher Q̂ and therefore should have improved characteristics as a switch in terms of insertion loss and isolation.