The response characteristic of a femtosecond low temperature GaAs (LT-GaAs) photoconductive switch formed in a coplanar waveguide at different voltage biases is studied with the femtosecond photocurrent autocorrelation measurement technique. The experimental results show that the switching time increases when the bias voltage is increased from 103 to 105 V cm−1. We provide a physical model, combining the potential barrier lowering (the Frenkel–Poole effect) and the field-enhanced thermal ionization, to give a complete explanation to the response characteristic of the LT-GaAs photoconductive switch at larger varying bias fields ranging from 103 to 105 V cm−1.

The electromagnetic susceptibility model of discontinuous microstrip circuits with the presence of a uniform plane incident wave is established. First, the analytical expressions are modeled as equivalent voltage and current sources for discussing the global effect of the incident plane wave on the associated interconnects. Then, these field-induced equivalent source expressions are incorporated into ADS circuit solver, and a fast model is established for analyzing the output responses of discontinuous microstrip circuits, such as the cross bend, the band-rejection filter and the single-stage amplifier. The corresponding simulation results from the proposed model are validated by comparing the results from both simulation and measurement. The results also show that the incident plane wave may influence the output terminal responses significantly, and the proposed approach would be an efficient method to solve the electromagnetic susceptibility problems associated with the discontinuous microstrip circuits.