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The paper presents a procedure used in designing and fabricating a working model of a varactor tuned oscillator using microstrip circuitry. The design procedure includes mathematical models and their associated computer programs in Fortran Computer Language. The fabrication of the working model includes experimental techniques; both for measurements of oscillator components and for adjusting (trimming) the oscillator frequency.

Transferred-electron devices (TEDs) in microstrip rf circuits have been studied for use in frequency memory applications. The closest frequency spacing obtained for memory states in an experimental system is 22.4 MHz. Twenty states are available between 11.33 GHz and 10.755 GHz. It was shown possible to operate microstrip circuits in parallel to obtain resonances spaced half the spacing for each individual circuit. Electronic tuning of the whole set of frequency states by means of a varactor was demonstrated. The switch-on characteristic of the states was studied, and it is shown that the memorizer's rf output signal is phase-locked to the input signal within 50 ns., See also report dated 20 Dec 74, AD-A004 996.

These meetings are intended to examine the development of a particular segment of electrical or electronic technology in some depth, and are designed to afford a comprehensive view of the topic to see what its current status is, and to determine where it is heading in the future. As well as new technical contributions in the fields of materials, and microwave and optical devices, papers covering overviews in the fields are included. The first general technical session covered advances in broad-band tuning of Gunn oscillators, the impact of heterojunctions on optoelectronics, microwave FET devices, and GaAs materials for IMPATTs as well as the IMPATT results. The other sessions covered optical devices, including the new distributed feedback injection laser, materials and processes; transferred-electron devices; microwave FET devices, including over 40% power-added efficiency at X-band; and avalanche devices., Supplement to report dated 3 Mar 76, AD-A022 039.

A preliminary energy band structure of SbSI obtained by empirical pseudopotential method is discussed with references to existing optical data and other calculations. Brief discussions on band structure results for niobium, of calculations on the angular-dependent photoemission from GaAs and charge distributions in transition metal compounds, TiC, TiN, ZrC, and ZrN are included.

The TRUMP program, developed by Arthur Edwards of the Lawrence Radiation Laboratory, has been adapted for use on the IBM 360/44, under the name CTRUMP. Modifications were made to enable calculations of three-dimensional heat flow in solid state devices, as a result of internal conduction and internal heat generation with constant boundary conditions. CTRUMP was then used to calculate temperature rise in thin film and carbon resistor models, as well as in a model of a gallium arsenide Gunn effect diode. An operating manual for CTRUMP is included as an Appendix.

The report describes work on a sensitive superheterodyne frequency downconverter to convert six channels in the 18-42 GHz range to the 4-8 GHz range. Accomplishments include: The design and fabrication of 26, 30, and 34 GHz Gunn diode oscillators providing +14 dBm output power; The design of broadly frequency selective channel dropping couplers which can be fabricated in dielectric image guide; The design and fabrication of Schottky-Barrier diode mixer mount with a 6-8 dB conversion loss over the 18-22 GHz band. The design and fabrication of an integrated mixer assembly in metal waveguide which includes both waffle iron and waveguide-below-cutoff filters, a 10 dB LO post-type coupler, and a single ended diode mixer; The design and fabrication of a coax to image guide mode converter (launcher); The evaluation of thin film attenuators to be used with image guide.

The emphasis of the investigation is centered on studies of active microwave effects in avalanche diodes, transferred electron diodes, microwave field-effect transistors, and on related microwave circuit, materials growth, and physical electronic techniques. In Section A, a report is made on the microwave solid state devices and circuits. Included are: Amplifier Properties; IMPATT Diode Load Characteristics; Interaction of Distributed IMPATT Oscillators; An IMPATT Diode Characterization; Microwave Transistor Studies; Compound Semiconductor Transistor Study; Computer Experiments in TRAPATT Diodes; and High Performance TEO. In Section B, a report is made on materials and fabrication techniques. The topics discussed are: The Epitaxial Growth of Thin GaAs Layers; Read Structures; and Electric-Current-Controlled Liquid Phase Epitaxial Growth of GaAs.

The report presents a technical assessment of present-day transferred electron (Gunn) devices, microwave avalanche devices, and microwave transistors and attempts to estimate their ultimate performance capabilities.

This report describes the research accomplished during the third biannual period of a three year research program dealing with advanced concepts of microwave generation and control in solids. A report is made on microwave solid state devices and circuits. Included are: GaAs Read Diodes; Amplifier Characteristics; Measurement of IMPATT Diode Amplifier Parameters; Computer Experiments on TRAPATT Diodes; High Power and Efficiency CW Transferred Electron Oscillators; Compound Semiconductor Transistor Study; Automated Network Analyzer; Submicron Gate Field Effect Transistor; IMPATT Diode Load Characteristics; and Interaction of Distributed IMPATT Oscillators. A report is also made on materials and fabrication techniques. The topics discussed are: The Epitaxial Growth of Thin GaAs Layers; Read Structures; and Electric-Current-Controlled LPE Growth of GaAs.

Various technological problems in the development of GaAs microwave devices are covered in this report. The work reported here includes: epitaxial growth of ultra-thin and high-resistivity films, study of the relationship between device performance and material parameters using IMPATT and LSA Gunn diodes, growth of semi-insulating substrates and characterization techniques, and study of ion implantation as a tool for microwave device fabrication.

The report describes the completion of the studies, initiated in FY 69, carried out to assess the practicability of applying microwave integrated circuits and solid state fundamental oscillators to future sensor subsystems for radar and communications, including data relay. The X-band eight-element phased array was evaluated, a simple MIC module including a printed antenna was constructed and studies were carried out of avalanche diode oscillator modulation characteristics, MIC IMPATT avalanche diode oscillators, MIC antennas, and MIC evaluation techniques.

The report describes the results of a program of investigation concerning the reliability and failure modes of gallium arsenide Gunn and IMPATT diodes. Data is presented concerning the burn-out distribution in time of Gunn diodes. Also, the changes in dc and RF parameters of 700 Gunn and 100 gallium arsenide IMPATT diodes resulting from 24 to 168 hours of dc high temperature burn-in are present. The results of long-term RF burn-in experiments are presented. Optical and electron microscope photographs are presented which are used in the analysis of the manufacturing defects leading to early failure in Gunn diodes. Correction of these defects has lead to an increased 24-hour burn-in yield., See also Semi-Annual report, AD770528.

This is the fourth quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are the following: High-power Gunn-effect devices; gunn-effect amplifiers; modulation properties of gunn-effect devices; avalanche-diode amplifiers; high-efficiency avalanche diodes; nonlinear operating characteristics of IMPATT diodes; solid-state device fabrication; and, instabilities in germanium., See also AD730636.

This report deals with the progress made during the seventh quarterly period of a solid state microwave oscillator and amplifier research and development program. Included are the results of studies of transferred electron punch-through injection, and avalanche diodes and solid state materials. Discussed first are LSA diodes and circuits, Gunn effect amplifiers and oscillators, a PCM Gunn oscillator, and GaAs materials studies. Next discussed are high average power TRAPATT diode structures and research on high frequency TRAPATT oscillators. Also reported are two studies of punch-through injection (Baritt) diodes, one for high frequency cw operation and the other for low frequency cw operation. Work on relaxing avalanche mode (RAM) oscillators is reported along with a summary of a new study on microwave transistors. The report concludes with a discussion of the progress made on ion implantation, on vacuum epitaxial growth in silicon and on ionization rates in GaAs., See also report dated June 72, AD-748 241.

Contents: Solid state devices and components; Antennas and propagation; Communication circuits and components.

The patent describes a circuit for providing accurate timing pulses to steer an antenna array. A Gunn device coupled at the input of each transmitting element supplies a single pulse at predetermined time intervals to the element enabling time delay steering of the antenna array.

This report covers the fabrication of two solid state 14.4-15.2 GHz radio sets. These were fabricated to demonstrate the feasibility of a low-cost microwave radio set. This equipment has been designed for line-of-sight microwave communications and could fulfill requirements where microwave communications are now too expensive, such as in intra-base and bare-base voice and/or sensor communications operations. (Author)

The research program is concerned with new techniques for microwave signal generation. The emphasis of the investigation is on studies of active microwave effects in bulk semiconductors and on physical electronic phenomena. Specifically the study areas include the domain and Limited Space charge Accumulation (LSA) modes of the Gunn-effect, Impact Avalanche and Transit Time (IMPATT) and Trapped Plasma Avalanche Transit Time (TRAPATT) oscillators and amplifiers and microwave semiconductor materials properties. This research is being undertaken to further the understanding of the physical mechanisms and processes which are involved and to obtain information of use in the design of improved microwave sources. The work accomplished during the tenth quarterly period is discussed in this report. (Author), See also Quarterly progress rept. no. 9, AD-871 992.

Contents: Capacity limits of thin-layer memories; Storage based on the Gunn effect., Unedited rough draft trans. of Nachrichtentechnik (East Germany) v20 n7 p264-268 1970.

The purpose of this work was to develop a GaAs Sheet Gunn (Coplanar) device and circuit capability such that maximum power could be extracted from the device. Electronic tuning of the device over the 4.8 - 5.2 GHz range was also desired. Difficulties in growing N layer on semi-insulating substrates, and premature breakdown in finished devices even under pulsed conditions precluded achievement of the original contract objectives. The contract was redirected towards obtaining high power by means of amplifiers. Theoretical and experimental analysis of the Distributed Unidirectional Microwave Amplifier showed that this device offered one method of achieving the desired microwave power levels. A DUMA test vehicle employing six 0.7 W avalanche diodes demonstrated amplification at the 5-watt level, and showed electronic gain at powers as high as 9 W. (Author)

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: Microwave noise emission from indium antimonide; Instabilities in Germanium; Transverse and magnetic field effects on instabilities in bulk semiconductors; Gunn effect amplifiers; High power gunn effect devices; Large signal analysis of avalanche diodes; Multifrequency operation of avalanche diodes; Multifrequency operation of avalanche diodes; Solid state device construction and evaluation. (Author), See also Quarterly progress rept. no. 10, AD-871 171.

The harmonic content of solid state GaAs Gunn effect oscillators has been experimentally investigated using a lamellar grating far-infrared interferometer. The experiment has shown that power as low in frequency as 6 GHz can be modulated by the grating and that the instrument can be used in this frequency range with appropriate high-pass filters and above 60 GHz without filters. A number of the experimental difficulties encountered and instrumental modifications made to reduce the low frequency operating limit are discussed. A high dc bias mode of operation of a high-purity n-type epitaxial GaAs detector was discovered and its properties were investigated. This sensitive, broad-band detector, which had a response time of about 20 nsec, was used for the harmonic content measurements. In general, only a few harmonics of the X-band Gunn effect devices were observed and these died off rather rapidly. The experimental results were in fairly good agreement with theoretical predictions and indicate that the relative harmonic content increases with n/f. No definite correlation between harmonic content and bias voltage was found. The highest frequency at which power was observed was 82 GHz, a tenth harmonic. Thus the results do not contradict the predicted upper frequency limit of operation for these devices. (Author), See also Volume 1, AD-883 604L and Volume 3, AD-883 608L.

The aim of this project is to study the spurious emissions from transit-time Gunn diodes which affect the electromagnetic compatibility of these devices. Harmonic emission far from the fundamental and noise emission in the vicinity of the fundamental have been studied. Efforts on the harmonic program this year were directed toward the isolation and elimination of extraneous reflections and interferences in the far infrared interferometer. Noise from Gunn effect oscillators has been extensively measured. A major contribution to the noise spectrum is upconverted flicker noise present in the diode current. An analytic treatment of this up-conversion process is given. Good agreement is found between measured and calculated spectra. From a single noise measurement performed on a sample in a standard circuit, one may calculate the sample's noise spectrum in an arbitrary circuit if the loaded Q, power, and voltage pushing are known. Transit-time Gunn diodes are characterized by an equivalent noise temperature of 7500K which is comparable to the noise temperature of klystrons. (Author)

The report summarizes work done over a period of three years on a research program directed to the suppression of undesired emissions from active bulk-solid and epitaxial devices. Major emphasis was placed on the spurious emissions of Gunn devices. Both harmonic emission far from the fundamental and noise emission in the vicinity of the fundamental were studied. The technique of Fourier spectroscopy was newly applied to the study of harmonic emissions over the range 8 - 500 GHz. It was found that for Gunn devices operated in the hybrid and LSA modes harmonic power dropped rapidly with increasing frequency. The highest harmonic observed was the tenth (at 82 GHz) of a high-power pulsed LSA X-band device. (Author), See also Volume 2, AD-883 607L.

This effort is the first program to develop high power solid state microwave oscillators to compete with and eventually replace magnetrons in the 100 to 200 watt range at X and Ku-bands. The Limitated Space-charge Accumulation (LSA) mode in GaAs was developed to a point that produced 100 watts peak and 200 mw average power at X-band and 150 watts peak at Ku-band. (Author)

The field dependent electron drift velocity in GaAs has been calculated on the basis of a Monte Carlo simulation of electron motion in k-space. Three scattering processes have been taken into account. These include interactions with longitudinal polar optical mode phonons, non-polar optical mode phonons and acoustical phonons. Numerical calculations including accuracy estimates have been performed for lattice temperatures in the range 200 - 400 degrees K. The results show the threshold field to be nearly temperature independent. The negative differential mobility increases with decreasing temperature, while the peak to valley ratio is nearly constant. An outline is given of work being done in order to include scattering by neutral and ionized impurities. This will make calculations possible for temperatures down to below liquid nitrogen and impurity concentrations up to 10 to the 17th power/cc. (Author)

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: Microwave radiation from indium antimonide; Instabilities in germanium; Transverse and magnetic field effects on instabilities in bulk semiconductor plasmas; Gunn-effect oscillators and frequency converters; Gunn-effect amplifiers; High-power Gunn-effect devices; Avalanche-diode devices; High-power avalanche diodes; High-efficiency avalanche diodes; Solid-state device construction. (Author), See also Quarterly progress rept. no. 6, AD-855 150.

The continuing study of GaAs LSA devices in circuits with the aid of several computer programs and an analysis has been made, as a function of parameters, using I-V effects representing space-charge accumulation. Refined results for calculation of dc electric field as a function of position are presented for two-frequency LSA. Gunn effect diodes capable of average input powers up to 10 watts with CW output powers up to 120 mW have been studied and a protective 'crowbar' is discussed. Electronic tuning of LSA oscillations with bias and temperature is discussed, along with critical skin depth effects. A technique for estimating the effective thermal resistance of thick devices is presented. Development of the pulse bridge to be used for high electric field magnetoresistance measurements is nearly complete. A simplified model for avalanche resonance pumped semiconductor diodes has been developed in terms of its voltage current relation and its equivalent circuit. Schottky barrier avalanche diodes have been fabricated. Hot electron diffusion theory in Silicon was continued and N+ - P junctions constructed for tests of the theory. Techniques work at obtaining millimeter waves from bulk indium antionide is discussed., See also Quarterly progress rept. no. 7, AD-860 331.

The report traces out the development of the low frequency equivalent circuit of the diode-on-a-post type waveguide LSA oscillator and shows that circuit conditions exist for the low frequency oscillations. The input impedance presented to a diode mounted in a rigid waveguide combined with a three-quarter wavelength choke is analyzed in some detail and it is shown that this structure also can support a low frequency oscillation. Experiments in a coaxial cavity have shown the existence of two modes of oscillation. In the higher frequency mode, thought to be LSA, the effective diode capacitance was 1.6 times the cold capacitance, and N/f for the fundamental frequency of oscillation was less than 200,000 sec/cc. A description is given of a resonant waveguide iris structure combined with a ridge waveguide which produces X band output as only the second harmonic frequency. Preliminary experiments have given 13 watts at 4% efficiency at X band and over 50 watts at 10% at the fundamental frequency. (Author)

Electromagnetic compatibility of GaAs oscillators as a function both of contacting procedures and of active region thickness was investigated by evaluation of their output spectra. Twenty-three devices were measured for spectral output. (Author)

The behavior of several different Gunn oscillators operating into a resistive load is experimentally investigated. The effects of applied bias, load resistance, and temperature on oscillation frequency, power, and efficiency are presented. It is seen that at microwave frequencies circuit resonances influence diode behavior and that complete knowledge of the microwave circuit is required. It is then demonstrated that under certain circumstances, such as for the diodes and circuit employed here, the domain capacitance plays a major role in determining frequency behavior and can lead to wide tuning ranges and mode switching determined by the applied voltage or temperature. Applications of this effect and follow-on work are suggested. (Author)

The negative resistance arising in gallium arsenide transferred electron oscillators has been observed over a broadband in material of doping greater than that associated with Limited Space charge Accumulation (LSA) operation. The behavior was characterized by strong circuit dependence, as with LSA, and by high efficiency of as great as twenty percent in pulsed operation. The transition from transit-time operation to nearly LSA operation has been seen experimentally as a continuous function of circuit tuning. An expected decrease in diode capacitance has been observed during the tuning from domain transit operation to LSA. Some clues to the origin of the high efficiency are discussed. The operation of material with gold-germanium alloyed contacts is compared to that with the superior solution grown epitaxial contacts. (Author)

This research program is concerned with new techniques for microwave signal generation. The emphasis of the investigation is on studies of active microwave effects in bulk semiconductors and on physical electronic phenomena. Specifically the study areas include the domain and Limited Space charge Accumulation (LSA) modes of Gunn effect, Impact Avalanche and Transit Time (IMPATT) diodes, microwave semiconductor materials and fundamentals, and a special study dealing with field emission of electrons from semiconductors into a vacuum. This research is being undertaken to further the understanding of the physical mechanisms and processes which are involved and to obtain information of use in the design of improved microwave sources. (Author), See also Quarterly rept. no. 3, AD-844 679.

The publication contains a simple non-mathematical introduction to the theory of the Gunn oscillator and L.S.A. oscillator. The difficulties that have occurred in the fabrication of devices and materials are discussed. Predictions of the commercial availability of devices in the future are made. (Author)

Research was conducted on Gunn oscillators. Successful hybrid mode operation has been obtained over 0.75 to 5 times transit-time frequency in single diodes of epitaxial GaAs. Research was conducted on avalanche (IMPATT) diodes. The broadband negative resistance properties of a 1.3 ohm-cm, 4.5 micron N-region punch-through avalanche diode have enabled its operation as a microwave generator over a 1 to 10 GHz frequency range with 2 to 10 percent efficiency. Large-signal sample impedances were obtained for both the pure transit-time mode and the low-frequency mode was found to be characterized by the necessary presence of an idler frequency at the second harmonic. Research on gallium arsenide crystal growing is also reported. Work on the solution growth method has shown considerable promise. An elementary theory for the magnetoresistance measurement of the Hall mobility, including the correction for the finite geometry of the practical diodes, is presented, and several practical sources of measurement error are discussed. (Author)

The report contains the results of a program to develop and build an electronically steerable MIC linear array with a single MIC receiver front end and the necessary array feed structure. The linear array consisted of four modules in a single housing bolted to a second housing containing four cylindrical waveguide antennas. Phase shifters for beam steering and polarization diversity were tight-coupled meander line, nonreciprocal ferrite structures flux driven to obtain effectively 4-bit operation. A varactor tuned MIC Gunn oscillator was investigated for use as the local oscillator. A new design approach consisting essentially of lumped tuning elements was used. A mathematical model for this approach was generated and computerized. A new design approach in phase shifter flux drivers using standard commercial components was derived. (Modified author abstract)

A Ka-band amplifier structure with 7.5 GHz bandwidth and 6 dB gain was fabricated. Simple adjustments lead to 15 dB gain with 2.5 GHz bandwidth. Measurements utilize double cosine tapered waveguide matching sections terminated by reduced height waveguide and calibrated sliding shorts. From slotted line measurements of reflection coefficients, two port cavity S parameters may be obtained. Insertion of the diode gives new reflection coefficients from which diode impedance can be separated. The accuracy of the calculated diode and waveguide parameters can be checked by testing calculated reflection gain vs. measured reflectometer gain over the frequency range using various calibrated short positions. Using the diode terminal impedance data, computer optimized matching circuits can be designed for particular gain and bandwidth requirements. (Author)

The research is concerned with the investigation and utilization of various phenomena and techniques for the generation, amplification, detection and control of electromagnetic energy at microwave frequencies. The work is mainly oriented toward an investigation of the basic properties, capabilities and potential of: Avalanche transit-time devices including IMPATTs and TRAPATTs; Transferred-electron devices; Microwave field-effect transistors; Microwave integrated circuits.

A general noise theory has been developed for a nonlinear, self-oscillating device in a parallel G-L-C circuit. Variation of the nonlinear device admittance with both RF voltage and bias voltage is incorporated in the theory and the sources of noise are lumped into two equivalent noise generators: a video noise voltage generator and an RF noise current generator. The present study extends the work of Sweet by including the RF voltage dependence in the theory and by applying the theory to a quenched-mode admittance model of transferred-electron (TE) devices. The noise theory is used to study AM and FM TE oscillator noise as functions of load conductance, bias voltage, cavity tuning and carrier doping density for uniformly doped TE devices. (Modified author abstract), See also report dated May 73, AD-764 259.

The noise generated by Gunn diode microwave oscillators was studied to determine the physical causes of noise, the relation between low frequency and microwave noise, and to develop an equivalent circuit for the diode. The use of a cavity to reduce FM noise was investigated. Methods for optimizing the performance of IMPATT diode oscillators, including noise performance, were studied. Portions of this document are not fully legible.

The report contains a summary of the work accomplished during the three-year period of research and a list of the technical reports issued as part of the program. Also included is a detailed review of the work, performed during the twelfth quarterly period, on microwave solid state devices and circuits and on solid state materials and fabrication techniques. Specifically, the topics discussed are: Amplifier properties; high frequency high efficiency avalanche oscillations; computer aided analysis of Schottky Barrier Baritt diodes; Baritt devices; microwave transistor studies; multi-mesa TRAPATT fabrication; computer experiments on TRAPATT diodes; high performance transferred electron oscillators; growth and evaluation of InP for LSA oscillations; ohmic contacts to n+ InP; ion implantation; ionization rates in GaAs; vacuum epitaxial growth in silicon; and steady state liquid phase epitaxial growth of GaAs. (Modified author abstract)

Techniques for improving the performance of radar microwave links were evaluated. State-of-the-art modules such as a tunnel diode amplifier, balanced mixer, Gunn diode local oscillator, and a solid-state IF amplifier were procured and evaluated in the laboratory. Selected components were then tested in an operational system for 3 months, and recordings of received signal level on two adjacent links were correlated with existing weather conditions and system outages. The results of the field and laboratory evaluations indicate that significant performance improvement can be obtained by replacement or modification of certain components of the existing system. (Author)

A Ka-band local oscillator was developed that provides 16 milliwatts of CW RF power using a solid state Gunn source. The source operates at 33140MHZ plus or minus 0.5MHZ, and will be used in the AN/SPN-42 Carrier Landing System. The local oscillator has been tested over the ambient temperature range -40C to +71C. Over this temperature range it showed a power stability of plus or minus 0.15db, and a frequency stability of plus or minus 900KHZ. It is recommended that the local oscillator be incorporated into an AN/SPN-42 system and evaluated under actual operating conditions. (Author)

A-44003*Gunn diodes, *Semiconductor devices, *Gallium arsenides, *Photoconductivity, Optical detectors, Infrared detectors, Gunn effect, Photodetectors, Carbon dioxide lasers, Helium neon lasers, Radiation effectsThe room temperature response (conductance) of GaAs material in a GUNN device structure under the influence of 10.6 micrometer and 0.6328 micrometer irradiation was investigated. Both continuous wave and pulsed irradiations were used in making measurements on devices placed in dc and 60 Hz dynamic test circuits. Negative and positive conductance changes were determined from the CO2 and HeNe fluxes, respectively. The responsivity of the GUNN device under CO2 irradiation was calculated to be 0.023 A/W. Negative conductance change was attributed to thermal heating whereas the positive change was interpreted as resulting from carrier generation (photoconductive effect). (Author)

D Semiconductor Devices.Semi-annual rept. no. 2, 1 Apr 72-1 Apr 73,2Ramachandran,T. B. ;Heaton,J. L. ;DAAB07-72-C-0101ECOM0101-72-2*Gunn diodes, *Semiconductor diodes, Reliability(Electronics), Gunn effect, Microwave oscillators, Gallium arsenides, Silicon, Transient radiation effects, FailureIMPATT diodesThe interim report describes the results of a continuing program of investigation concerning the reliability and failure modes of gallium arsenide Gunn and IMPATT diodes, and silicon IMPATT diodes. Data is presented concerning the burn-out distribuiton in time of Gunn diodes. Also, the changes in dc and RF parameters of 700 Gunn and 100 gallium arsenide IMPATT diodes resulting from 24 to 168 hours of dc high temperature burn-in are present. (Modified author abstract)

ATE Device and Circuit Studies.Quarterly progress rept. no. 10, 1 Dec 72-1 Mar 73,10Haddad,G. I. ;Lomax,R. J. ;Tang,D. ;F30602-71-C-0099AF-5573557303RADCTR-73-157See also Quarterly progress rept. 8/9, AD-759 833.(*semiconductor devices, *microwave equipment), (*integrated circuits, microwave equipment), avalanche diodes, microwave amplifiers, microwave oscillators, field effect transistors, silicon, gallium arsenides, manufacturinggunn diodes, impatt diodes, avalanche diodesThe tenth quarterly report investigates theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are: Modulation properties of Gunn-effect devices, nonlinear operating characteristics of IMPATT diodes, high-efficiency avalanche diodes, properties of TRAPATT diodes, field-effect transistors, CW power capability of IMPATT devices, solid-state device fabrication., See also Quarterly progress rept. 8/9, AD-759 833.

MADE DURING THE EIGHTH QUARTERLY PERIOD OF A SOLID STATE MICROWAVE OSCILLATOR AND AMPLIFIER RESEARCH AND DEVELOPMENT PROGRAM. Included are the results of studies of transferred electron, punch-through injection, and avalanche diodes and solid state materials. Discussed first are a summary of LSA diode and circuit research at Cornell, research on thin LSA devices, a PCM Gunn oscillator, and InP materials studies. Next discussed are high average power TRAPATT diode structures, research on GaAs Schottky barrier avalanche diodes and research on high frequency TRAPATT oscillators. Also reported are two studies of punch-through injection (Baritt) diodes, one for high frequency CW operation and the other for low frequency CW operation. Work on microwave transistors is reported along with a review of progress, on an oscillator power combiner and IMPATT diode reflection amplifier. The report concludes with a discussion of the progress made on ion implantation, on vacuum epitaxial growth in silicon on ionization rates in GaAs, and on a microwave monolithic integrated circuit study. (Author)