Complete electromagnetic simulation of HEMT switch circuit

Electromagnetic (EM) only HEMT model was been proposed in [1]. In this paper, complete EM simulation has been performed on entire switch circuit. The dependences of switch performances on distributed and coupling effects can be quantitatively explained, and the prediction accuracy can be remarkably improved. Further, the EM simulation has been applied to an assembled switch with bond wires. Since a closed loop is formed by bond wires and the shunt HEMT at off switch arm, isolation is degraded when loop currents is induced by the coupling among bond wires. It has been noticed that there are two kinds of couplings, and the loop currents induced by these two couplings are in the opposite phase. The isolation degradation can be reduced or eliminated by current cancellation when the bond wire configuration is properly designed.