Chirp Band-Width Estimation of MM-Wave Pulsed-MPATT: A Study on the Dependence of Device Diameter and Bias Pulse-Width

In this work, the authors have studied the dependence of chirp bandwidth viz. intra pulse change in frequency on the bias pulse width and on the diode junction diameter of pulsed IMPATT diodes. Using a small signal simulation model and a suitable thermal model, intra pulse diode susceptance are computed and from the sustained oscillation condition, the circuit susceptance presented at the device terminal is calculated and frequency chirp bandwidth is estimated. The results are presented in details and would be useful for design optimization of pulsed IMPATTs at Wband.