Showing papers on "IMPATT diode published in 1971"
01 Aug 1971
TL;DR: A brief review summarizes mechanisms of operation, power output, efficiency, noise, and some important features of design and fabrication of microwave avalanche diodes of various types.
Abstract: Microwave avalanche diodes of various types (IMPATT, TRAPATT, etc.) can generate power sufficient for microwave receivers and some transmitters. This brief review summarizes mechanisms of operation, power output, efficiency, noise, and some important features of design and fabrication.
112 citations
01 Aug 1971
TL;DR: In this paper, the avalanche region of one-sided and two-sided abrupt junctions has been studied and the implications of these results with respect to IMPATT diode design are discussed.
Abstract: The avalanche region of one-sided and two-sided abrupt junctions has been studied. These are the structures most commonly utilized for IMPATT diodes. Numerical results are presented which show that n+-p Si diodes have much narrower avalanche regions, due to the unequal ionization rates in Si, than the complementary p+-n type. The implications of these results with respect to IMPATT diode design are discussed.
32 citations
01 Jan 1971
TL;DR: In this paper, the authors presented a power-noise characterization of a phase-locked IMPATT oscillator with respect to the output power and the corresponding FM noise in a range of operating conditions and showed that the best performance for each type of diode was obtained when operated at less than maximum power and at reduced efficiency.
Abstract: IMPATT diode characterization on the basis of output power and the corresponding FM noise figure over a range of operating conditions is presented. The characterization consists of families of power noise curves obtained for a phase-locked IMPATT oscillator where the supply current, load conductance, and the operating frequency are parameters. It is shown that the maximum output power and minimum FM noise are not achieved concurrently. In particular FM transmitter application, it is shown that the best performance for each type of diode was obtained when operated at less than maximum power (and at reduced efficiency) where the system benefits from the attending lower noise. Better system performance, this application, was obtained with the GaAs IMPATT diode. The power-noise characterization defines the optimum operating conditions for an IMPATT diode and provides a valid basis for the comparison of diodes for specific applications.
26 citations
TL;DR: In this article, the characteristics of TRAPATT oscillations in a p-in diode are discussed and an approximate semi-analytical solution for the diode voltage waveform is derived when the current is a square wave.
Abstract: The characteristics of TRAPATT oscillations in a p-in diode are discussed and an approximate semi-analytical solution for the diode voltage waveform is derived when the diode current is a square wave. It is shown that a traveling avalanche zone is not necessary to generate a dense "trapped" plasma and that the boundary conditions prevent the trapped plasma from completely filling the depletion layer. Typical voltage waveforms and corresponding diode power, efficiency, and impedance at the fundamental and higher harmonics are presented. When the diode current is a square wave the diode does not necessarily exhibit a negative resistance at all higher harmonics. A computer program for TRAPATT oscillations in a p-i-n diode is described. Its running time is two or three orders of magnitude less than more exact time domain computer analyses. Typical results of diode power, dc to RF conversion efficiency, and required circuit impedances are presented for several different current waveforms which are composed of up to the seventh harmonic of a square wave and the first two harmonics of a half-wave sine wave. It is shown that high-efficiency oscillations are possible with diode currents composed of only the fundamental and one harmonic.
15 citations
01 Aug 1971
TL;DR: Theoretical results for the effect of temperature upon the small-signal admittance of a Read diode are compared with the experiments in this paper, where some experimental results on the temperature dependence of an IMPATT oscillator are reported.
Abstract: Some experimental results on the temperature dependence of an IMPATT oscillator are reported. Theoretical results for the effect of temperature upon the small-signal admittance of a Read diode are compared with the experiments.
15 citations
TL;DR: In this paper, the basic theory of a space-charge transit-time oscillator is outlined in which phase lag of current is caused by using low-velocity injection, and large negative resistances are anticipated at microwave frequencies, giving generation of moderate power levels with low noise operation.
Abstract: The basic theory of a space-charge transit-time oscillator is outlined in which phase lag of current is caused by using low-velocity injection. Large negative resistances are anticipated at microwave frequencies, giving generation of moderate power levels with low-noise operation. Approximate design calculations for a representative idealised structure 100 ?m square, based on silicon and operating at a frequency of 10 GHz, suggest a negative resistance of ?50 ? and a negative Q factor of -?/2, with a maximum output power of about 1 W and an efficiency of about 7%.
13 citations
TL;DR: In this article, a self-consistent one-dimensional large-signal analysis of a Read-type IMPATT diode oscillator is presented, which takes into account the device-circuit interaction.
Abstract: A self-consistent one-dimensional large-signal analysis of a Read-type IMPATT diode oscillator has been developed which takes into account the device-circuit interaction. The circuit is modeled by a lumped-equivalent network representing the diode package, and a cascade of lossless transmission lines with discontinuity capacitances representing the coaxial-line cavity with tuning slugs. A particular voltage waveform across the semiconductor wafer is not assumed a priori. Instead, the voltage and current waveforms are determined iteratively until they satisfy the equations for both the diode model and for the circuit. The waveforms are found to be highly dependent upon the circuit in which the diode is embedded.
11 citations
TL;DR: In this paper, the noise-current generator of a large-signal IMPATT oscillator is shown to be inversely proportional to the starting current of the avalanche starting current.
Abstract: The noise-current generator of a large-signal IMPATT oscillator is shown to be inversely proportional to the avalanche starting current. This is verified by a numerical study of a large-signal model of an IMPATT oscillator.
10 citations
TL;DR: In this paper, an oscillation efficiency up to 28 per cent was obtained at 10 GHz in the computer simulation of large-signal operation of an improved Si Read Diode, which has a Schottky barrier instead of a p-n junction in order to avoid the harmful minority carrier storage effect.
Abstract: An oscillation efficiency up to 28 per cent was obtained at 10 GHz in the computer simulation of large-signal operation of an improved Si Read Diode. The diode has a Schottky barrier instead of a p-n junction in order to avoid the harmful minority-carrier-storage effect. Temperature was found to have a drastic effect on efficiency. When an operating temperature of 600°K was considered efficiency was reduced to 3.8 per cent. The structures analyzed have a narrow avalanche region as in Read's original proposal in contrast to the “extended-cathode” Read diode studied by Scharfetter and Gummel. The diode is operated preferably at such a high bias current that the small-signal negative resistance is disappearing. In this way the diode requires less reactive current and the parasitic series resistance has less detrimental effect.
9 citations
TL;DR: In this article, the currents in a lightly doped high-field zone of an IMPATT diode subject to constant E field avalanche were derived for Si and GaAs with the avalanche period followed by a sudden transition to a lowvoltage carrier extraction period.
Abstract: Explicit solutions are derived for the currents in a lightly doped high-field zone of an IMPATT diode subject to constant E field avalanche. Resulting particle-current waveforms, diode impedances and r.f. powers are calculated for Si and GaAs with the avalanche period followed by a sudden transition to a low-voltage carrier-extraction period. It is concluded that the addition of a drift zone will only ease impedance matching and enhance efficiency when differences of either ionisation rates or drift velocities between electrons and holes exist.
8 citations
01 Jan 1971
TL;DR: Millimeter-wave IMPATT diodes have been operated both as stable amplifiers and as phase-locked oscillators for amplification of high data-rate phase-modulated signals.
Abstract: Millimeter-wave IMPATT diodes have been operated both as stable amplifiers and as phase-locked oscillators for amplification of high data-rate phase-modulated signals. Experimental results and a large signal analysis will be given.
TL;DR: An analytical relationship for the output-spectrum width of a low-level-operating IMPATT-diode oscillator is verified experimentally by measuring relevant diode and circuit quantities as well as the oscillator noise as mentioned in this paper.
Abstract: An analytical relationship for the output-spectrum width of a low-level-operating IMPATT-diode oscillator is verified experimentally by measuring relevant diode and circuit quantities as well as the oscillator noise. Good agreement between theory and experiment is found if the spectrum width is assumed to be predominantly due to f.m. noise.
TL;DR: In this article, a new process for the fabrication of semiconductor devices using a silicon nitride (Si 3 N 4 -masked thermally oxidized post-diffused mesa process (SIMTOP), which combines the advantages of both the mesa and planar processes was described.
Abstract: This paper describes a new process for the fabricating of semiconductor devices, using a silicon nitride (Si 3 N 4 -masked thermally oxidized post-diffused mesa process (SIMTOP), which combines the advantages of both the mesa and planar processes while eliminating the disadvantages peculiar to each An IMPATT diode was fabricated as a model vehicle for the process and the physical and electrical data are presented A comparison is made of voltage breakdown on rectifier devices made by the mesa, planar, and SIMTOP process Other applications of this new process are discussed and scanning electron microphotographs of the IMPATT structure are included
TL;DR: In this article, the effect of second-harmonic tuning of IMPATT diodes is examined on a conceptual basis, and a simple interpretation of the "single-frequency" admittances of the diode may be made.
Abstract: Two-frequency operation of IMPATT diodes is examined in this paper on a conceptual basis. It is shown that a simple interpretation of the "single-frequency" admittances of the diode may be made. An equivalent circuit is presented which shows that the effect of second-harmonic tuning is to introduce a nonlinear resonance into the fundamental input admittance. This occurs when the external circuit admittance is tuned to the neighborhood of the "single-frequency" oscillator admittance of the diode at the second-harmonic. Computer calculations of the tuned-harmonic mode, with the diode embedded in the simplest possible RF circuit, are presented to demonstrate the effect.
TL;DR: In this article, the authors describe the fabrication of parallel arrays of silicon IMPATT diodes in which the arrays are formed in a single diode chip using an integral heatsink for the diode arrays during wafer processing.
Abstract: Fabrication of parallel arrays of silicon IMPATT diodes in which the arrays are formed in a single diode chip is described. The technique includes formation of an integral heatsink for the diode arrays during wafer processing. For a given total active device area, the use of a parallel array of smaller diodes, rather than one large diode, allows a significant reduction in thermal impedance and consequently larger power-dissipation capability. The contribution shown in the letter is the ease and economy with which parallel arrays on an integral heatsink can be fabricated and handled as a single entity. In a diode operated at 6.4 GHz, 3.5 W of c.w. output power has been achieved with a room-temperature copper heatsink and a junction temperature of about 280°C.
TL;DR: In this article, a simple computer model of a TRAPATT diode is described, which is then interfaced with a time-domain representation of a stepped-impedance coaxial circuit.
Abstract: A simple computer model of a TRAPATT diode is described. This model is then interfaced with a time-domain representation of a stepped-impedance coaxial circuit, and a bias voltage is applied. Oscillations are then allowed to build up as dictated by the diode-circuit combination, and the performance of a given diode in a particular circuit may be evaluated.
Patent•
16 Aug 1971
TL;DR: In this paper, an intrusion detector detects motion of a human intruder into a selected volumetric space using an oscillator-detector avalanche or impatt diode operating above 4GHz is mounted within an open ended conductive cavity of a coaxial line construction.
Abstract: An intrusion detector detects motion of a human intruder into a selected volumetric space. An oscillator-detector avalanche or impatt diode operating above 4GHz is mounted within an open ended conductive cavity of a coaxial line construction to define the active transmitting and mixing element of an oscillator-mixer establishing an RF field in the selected space and receiving the motion related signals via a common antenna. The diode is exposed to both the transmitted and the echo signal and produces a Doppler frequency output signal which is connected to an alarm. The system antenna and a load coupling impedance transformer are selected to optimize the magnitude of the Doppler motion signal response sensitivity. The microwave frequency oscillator signal is modulated by loosely coupling a general purpose diode to the open end of the oscillator-mixer open ended cavity.
01 Jan 1971
Abstract: The performance of IMPATT oscillators and amplifiers for parametric amplifier pumps will be analyzed, citing noise, automatic power leveling, and power output. Experimental results at 35 GHz and 42 GHz will be discussed.
TL;DR: In this paper, the performance of a silicon IMPATT diode on the distinction between the undercoupled quenched oscillators, optimised oscillator, locked oscillator and stable amplifier was investigated.
Abstract: Qualitative experimental results are presented for a silicon IMPATT diode on the distinction between the undercoupled quenched oscillator, optimised oscillator, locked oscillator, stable amplifier, in relation to the gain, linearity and saturation power. The results are consistent with a nonlinear interpretation of the equivalent diode conductance.
01 Sep 1971
TL;DR: In this article, the technology and electrical operation of GaAs X-band IMPATT diodes is described and the CW efficiencies of 15.5 percent at 8 GHz and 15.1 percent at 9 GHz were obtained.
Abstract: The technology and electrical operation of GaAs X-band IMPATT diodes is described. CW efficiencies of 15.5 percent at 8 GHz and 15.1 percent at 9 GHz were obtained. The characterization measurements indicate that the internal efficiency of the devices may be considerably higher.
01 Aug 1971
TL;DR: In this paper, a digital-computer program was used to compare the performance of an n + -p-p + silicon avalanche diode with its more conventional p + -n-n + complementary junction in IMPATT-oscillator operation.
Abstract: A digital-computer program has been used to compare the performance of an n + --p--p + silicon avalanche diode with its more conventional p + --n--n + complementary junction in IMPATT-oscillator operation. The computer simulation of the former junction predicts a significant improvement of oscillator efficiency (20.1 against 13.9%).
16 May 1971
TL;DR: In this article, transmission cavity stabilization by TE/sub oln/mode cavities is applied to both Avalanche and Gunn diode X-band oscillators to yield simple, useful signal sources with FM noise lower than most other signal sources.
Abstract: The Avalanche or Gunn diode oscillators in simple single resonator circuits usually have considerably more FM noise then Klystron or crystal-oscillator, multiplier-chain type signal sources. Transmission cavity stabilization by TE/sub oln/ mode cavities is applied to both Avalanche and Gunn diode X-Band oscillators to yield simple, useful signal sources with FM noise lower than most other signal sources. Some additional studies show that a cavity stabilized silicon avalanche diode oscillator used as a synchronizing signal to injection phase lock a Gunn oscillator has the best combination of low FM and AM noise.
TL;DR: In this article, the impact avalanche transit-time (IMPATT) diode has been used to generate microwave power and amplify microwave signals in the microwave frequency range, where the negative resistance is based upon avalanche multiplication and the transit time effect of carriers.
Abstract: Publisher Summary This chapter discusses that when the pn junction diode is reverse-biased, then, current does not flow. However, when the reverse voltage exceeds a certain value, the junction breaks down and current flows with only slight increase of voltage. This breakdown is caused by avalanche multiplication of electrons and holes in the space-charge region of the junction. The pn junction in the avalanche breakdown condition exhibits negative resistance characteristics in the microwave frequency range. This negative resistance is exploited to generate microwave power and amplify microwave signals. As the negative resistance is based upon avalanche multiplication and the transit-time effect of carriers, the device has been called the “Impact Avalanche Transit-Time” (IMPATT) diode. IMPATT oscillators have produced continuous output powers ranging from 5 W at 12 GHz with an efficiency of 9 % to 37 mW at 106 GHz with an efficiency of 1.6 %. The chapter discusses some design considerations and fabrication techniques of laboratory models. Finally, the observed characteristics of experimental units are presented.
16 May 1971
TL;DR: In this paper, a method of controlling the conventionally noisy FM characteristics of an IMPATT diode oscillator by properly terminating the second harmonic frequency is described, and the result is characterized by a self-locking mechanism with a resulting mechanical tuning range, via a second harmonic circuit, of up to 100 MHz at lower X-band.
Abstract: A method of controlling the conventionally noisy FM characteristics of an IMPATT diode oscillator by properly terminating the second harmonic frequency is described. The result is also characterized by a self-locking mechanism with a resulting mechanical tuning range, via the second harmonic circuit, of up to 100 MHz at lower X-band. Effects of second harmonic tuning on IMPATT reflection - type amplifier operating bandwidth is also discussed.
TL;DR: In this article, two high-efficiency avalanche diodes, each placed in opposite polarity to the other at the ends of an approximately one-half wavelength transmission line, have worked as a high-power reflection-type amplifier.
Abstract: Two high-efficiency avalanche diodes, each placed in opposite polarity to the other at the ends of an approximately one-half wavelength transmission line, have worked as a high-power reflection-type amplifier. The circuit configuration is called an antiparallel pair of high-efficiency avalanche diodes. The antiparallel amplifier has provided 200-W pulsed output power with a 10-dB gain at 1.01 GHz.
Patent•
31 Mar 1971TL;DR: In this paper, the terminals of a first avalanche diode are shunt coupled to a microwave transmission line, and at least one other diode of opposite polarity of at least two other avalanche diodes are also coupled to the same line.
Abstract: The terminals of a first avalanche diode are shunt coupled to a microwave transmission line. The terminals of opposite polarity of at least one other avalanche diode are also shunt coupled to the microwave transmission line. Complementary microwave circuitry and proper location within a suitable microwave resonant circuit enables the multiple avalanche diodes to operate in the anomalous mode in an oscillator, amplifier, or frequency multiplier when reversed biased by an appropriate signal.
TL;DR: In this article, it was shown both theoretically and experimentally that the a.m.- and f.m.noise spectra of transmission and reaction-cavity-stabilised Gunn oscillators differ considerably for high modulation frequencies, i.e. frequencies exceeding the 3 dB bandwidth of the cavities.
Abstract: It is shown both theoretically and experimentally that the a.m.- and f.m.-noise spectra of transmission- and reaction-cavity-stabilised Gunn oscillators differ considerably for high modulation frequencies, i.e. frequencies exceeding the 3 dB bandwidth of the cavities.
Patent•
13 Jul 1971TL;DR: An avalanche diode of the IMPATT diode type as mentioned in this paper can be used as an oscillator, amplifier, or frequency converter and has a construction utilizing both N+P and NP+ junctions whereby improved power output and other operating characteristics can be attained.
Abstract: An avalanche diode, of the IMPATT diode type, which may be used as an oscillator, amplifier, or frequency converter and having a construction utilizing both N+P and NP+ junctions whereby improved power output and other operating characteristics can be attained.