A Computer Aided Study of Resonant Cap Impatt Amplifiers using Radial Line Approach
01 Nov 1998-Iete Journal of Research (Institution of Electronics and Telecommunication Engineers)-Vol. 44, Iss: 6, pp 305-311
TL;DR: In this article, a computer aided numerical iteration technique is presented which would be suitable for optimum design and realisation of Impatt amplifiers with circular resonant cap cavities, and the dependence of the center frequency of the amplifier on the device and circuit impedance with the device placed at the center of the circular cavity has been studied.
Abstract: A computer aided numerical iteration technique is presented which would be suitable for optimum design and realisation of Impatt amplifiers with circular resonant cap cavities. The dependence of the centre frequency of the amplifier on the device and circuit impedance with the device placed at the centre of the circular resonant cap cavity has been studied. The real part of the impedance seen at the cap edge by an incoming signal has been studied along with the geometrical parameters of the cavity using a numerical iteration process through solution of related electromagnetic field equations. The dependence of the centre frequency on the cap radius, cap height, post radius and the cap thickness has also been studied.
References
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TL;DR: A series of p-type IMPATT diodes (p+pn+) have been fabricated from epitaxially grown silicon for operation as oscillators at K a -band frequencies as mentioned in this paper.
Abstract: A series of p-type IMPATT diodes (p+pn+) have been fabricated from epitaxially grown silicon for operation as oscillators at K a -band frequencies. A maximum CW output power level of 700 mW at 29.6 GHz, a maximum conversion efficiency of 10.9 percent, and a minimum FM noise parameter, M, of 25 dB have been measured on this series of p-type diodes. A diode oscillating in a variable height radial disk cavity was frequency tuned from 27.5 to 40 GHz, covering the entire K a -band, with a 1.4 dB power variation over the tuning range. The minimum CW output power of this tunable oscillator was 360 mW at 6.5 percent efficiency.
30 citations
TL;DR: In this paper, the effects of bandwidth on transient response of the IMPATT amplifiers as applied to phase modulated signals and amplitude-modulated signals are investigated in detail, and the relationship between the transition switching time and the amplifier bandwidth is derived.
Abstract: Nonlinear characteristics, large-signal effects, and transient response of IMPATT amplifiers are analyzed leading to clear understanding of various nonlinear and large-signal phenomena which are often observed experimentally on IMPATT diodes operated as stable (linear) amplifiers or injection-locked oscillators. Effects of bandwidth on transient response of the IMPATT amplifiers as applied to phase-modulated signals and amplitude-modulated signals are investigated in detail. The relationship between the transition (switching) time and the amplifier bandwidth is derived. Capabilities and limitations of IMPATT diodes operated as stable amplifiers or injection-locked oscillators are discussed.
24 citations
NEC1
TL;DR: In this paper, a method of graphical interpretation of the characteristics of negative-resistance diode simplifiers, based on the large-signal diode admittance chart, is presented.
Abstract: The behavior of nonlinear power amplifiers using IMPATTdiodes in both stable and injection-locked modes was investigated theoretically and experimentally. A method of graphical interpretation of the characteristics of negative-resistance diode simplifiers, based on the large-signal diode admittance chart, is presented. The characteristics of the simplified model of the reflection-type amplifier using an X-band Read-type IMPATTdiode have been evaluated. The experimental results of power amplification using an X-band Si IMPATTdiode in both stable and injection-locked modes under various circuit conditions are given. It was shown that nonlinearity of the IMPATT diode susceptance causes distortions in the amplification and injection-locking characteristics.
18 citations
01 Jan 1972
TL;DR: In this paper, the behavior of nonlinear power amplifiers using IMPATTdiodes in both stable and injection-locked modes was investi- gated theoretically and experimentally.
Abstract: The behavior of nonlinear power amplifiers using IMPATTdiodes in both stable and injection-locked modes was investi- gated theoretically and experimentally. A method of graphical inter- pretation of the characteristics of negative-resistance diode simpl- ifiers, based on the large-signal diode admittance chart, k presented. The characteristics of the simplhied model of the reflection-type amplitier using an X-band Read-type IMPATTdiode have been evalu- ated. The experimentaf results of power amplification using an X-band Si IMPATT diode in both stable and injection-locked modes under various circuit conditions are given. It was shown that non- linearity of the IMPATT diode susceptance causes distortions in the amplification and injection-locking characteristics.
17 citations
TL;DR: In this paper, a frequency independent lumped equivalent circuit is proposed for characterizing the large-signal behavior of IMPATT diodes, which has five elements including a negative resistance, two of which are quadratic functions of the single-frequency RF voltage across the device.
Abstract: A frequency-independent lumped equivalent circuit is proposed for characterizing the large-signal behavior of IMPATT diodes. It has five elements including a negative resistance, two of which are quadratic functions of the single-frequency RF voltage across the device. It is used for computer-aided analysis and the design of reflection-type negative-resistance amplifiers employing IMPATT diodes. The frequency response of the amplifier is calculated for different input power levels and the nature of the results is found to be in agreement with published experimental results.
13 citations