High power heterojunction GaAs Switch IC for GSM application

A high handling power of 4W and low controlled voltage of 3V GaAs Switch IC (SWIC), which is available in the hand-held phone unit for GSM dual and triple mode applications, has been developed. As a basic SW element, a shallow Vth HJFET has been adopted. By optimizing the structure of the recessed gate, the substrate epitaxial layer, and multi-gate FET SW circuits, the SWIC has exhibited high linearity of a Pin-Pout with P-ldB (Pin) of more than 38dBm, an insertion loss of less than 0.6dB and an isolation of more than 22dB in a wide band frequency range of 0.5 to 2.0GHz.