Large-signal characterization of DDR silicon IMPATTs operating up to 0.5 THz

Abstract

Large-signal (L-S) characterization of double-drift region (DDR) impact avalanche transit time (IMPATT) devices based on silicon designed to operate at different millimeter-wave (mm-wave) and terahertz (THz) frequencies up to 0.5 THz is carried out in this paper using an L-S simulation method developed by the authors based on non-sinusoidal voltage excitation (NSVE) model. L-S simulation results show that the device is capable of delivering peak RF power of 657.64 mW with 8.25% conversion efficiency at 94 GHz for 50% voltage modulation; whereas RF power output and efficiency reduce to 89.61 mW and 2.22% respectively at 0.5 THz for same voltage modulation. Effect of parasitic series resistance on the L-S properties of DDR Si IMPATTs is also investigated, which shows that the decrease in RF power output and conversion efficiency of the device due to series resistance is more pronounced at higher frequencies especially at the THz regime. The NSVE L-S simulation results are compared with well established double-iterative field maximum (DEFM) small-signal (S-S) simulation results and finally both are compared with the experimental results. The comparative study shows that the proposed NSVE L-S simulation results are in closer agreement with experimental results as compared to those of DEFM S-S simulation.

Multiple-band large-signal characterization of millimeter-wave double avalanche region transit time diode

“…7 at three bias current densities for a fixed voltage modulation (50 %). The reported large-signal results of DDR Si transit time devices at 94, 140 and 220 GHz window frequencies [12] and the corresponding experimental results [17][18][19] are shown in Fig. 7 for the sake of comparison of RF performance of DAR and DDR Si IMPATTs at those frequencies.…”

“…The time and space dependent device equations i.e., Poisson's equation, continuity equation and current density equation are simultaneously solved under large-signal condition subject to appropriate boundary conditions. A doubleiterative simulation method [9][10][11][12][13] based on 1-D finite difference method (FDM) is used for this purpose. The device equations used in the simulation are given by …”

“…The large-signal program [9][10][11][12][13] is first run for a complete cycle (i.e. 0 ≤ ωt ≤ 2π ) and then repeated for consecutive cycles to ensure the oscillation stability.…”

“…The large-signal properties of DAR Si diode are obtained from indigenously developed large-signal simulation software based on NSVE model [9][10][11][12][13]. The simulation involves simultaneous numerical solution of the both time and space dependent device equations subject to appropriate boundary conditions at the depletion layer edges.…”

Large-signal characterization of millimeter-wave IMPATTs: effect of reduced impact ionization rate of charge carriers due to carrier-carrier interactions

“…The temperature is taken to be 500 K. Since the junction temperature of the IMPATT devices are kept nearly 500 K (just below the burnout temperature of Si, i.e. 575 K) by appropriate heat sinking arrangement in order to obtain maximum RF Power output [18,19]. The α e,h versus 1/ξ graphs plotted from the Eq.…”