Search

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)

FIERS. Both subcritically doped as well as supercritically doped devices are considered. A large-signal analysis of subcritically doped, negative conductance-type devices is developed. The analysis is one-dimensional and includes the effects of diffusion, where the diffusion coefficient is dependent upon the electric field. First-order nonlinear equations involving the dc and RF electric fields in the material are obtained for given dc and RF currents driven through the diode. The equations are solved on a digital computer and the results are presented. Various dc and RF characteristics of the diodes are examined. The effects of diffusion, bandwidth considerations, the effects of bias, temperature effects and the effects of doping density are discussed. The experimental study of stable negative conductance amplifiers is presented.

The power-frequency performance of microwave transistors, Gunn-Effect Impact Avalanche Transit Time (IMPATT), Trapped Plasma Avalanche Triggered Transit (TRAPATT), and Limited Spacecharge Accumulation (LSA) devices is graphically presented. Based on foreseeable advances in technology, the 1975 expected performance, with a brief discussion of underlying developments as of September 1971, is included. Important aspects of device performance in addition to power are being studied at Cornell University and the University of Michigan under contract with Rome Air Development Center. Two results from these contracts are summarized: The Effect of Temperature on the Operation of an IMPATT Diode, and Avalanche Region Width in Various Structures of IMPATT Diodes. (Author)

An integral heat sink technology for the fabrication of high efficiency transferred electron oscillators was successfully developed. Using this technology, typical device efficiencies were increased from between 3 and 5% to between 6 and 9%. The best efficiency obtained was 14%, the highest efficiency reported to date for cw TEOs. The highest power output obtained from a single mesa device was 400 mW. The best power output-efficiency combination was 305 mW with 9% efficiency in X-band. A thermal analysis of a typical TEO structure was carried out. The influence of various device design parameters such as heat sink configurations, and nl product on device efficiency were studied. (Author)

Work pursued was intended to demonstrate the ability of frequency locked bulk effect sources to operate as distributed transmitter sources for a solid state radar system. A module design was evolved consisting of the bulk oscillator, its modulator, a transmit-receive switch, 6 bits of phase control, associated logic circuitry, and a polarization diverse radiator. A linear array of 16 such modules was constructed and evaluated. Additionally, the linear array was utilized as the transmitter-antenna of a solid state phased array radar system. The SPAR system detected stationary targets at ranges up to 11.5 kilometers and light aircraft at 3 kilometers. (Author)

The 1971 Conference was concerned with both the properties and applications of solid state and quantum electronic devices. The meeting was particularly concerned with a preliminary assessment of the future social implications of solid state device technology. Other applicational papers had to do with monitoring of pollutants in the atmosphere, solid state microwave devices in airborne radars, Gunn devices applied to miniaturized aircraft altimeters, Josephson junctions, laser applications to frequency standards, chemical lasers, noise problems in variety of high-frequency electronic generators and amplifiers including IMPATT and TRAPATT avalanche diodes, Gunn oscillators, LSA mode oscillators, transistors, chemical lasers, junction lasers, and the barrier injection transit time low-noise devices made with silicon., Proceedings of the Biennial Cornell Electrical Engineering Conference (3rd), Cornell Univ., Ithaca, N. Y., 17-19 Aug 71.

The document discusses the results of the experimental and theoretical investigations of surface acoustic waves propagating on piezoelectric substrates. It includes the parametric interactions, harmonic generation, parametric mixing of surface acoustic waves, interactions between light and surface acoustic waves, and the excitation of acoustic surface waves by a grating coupled Gunn oscillator. The accomplished results are reported in four papers entitled (1) Harmonic generation of Rayleigh waves in LiNbO3 substrates with a thin film, (2) Nonlinear interaction of surface waves with pseudo-surface waves, (3) The light diffraction efficiency of acoustic surface waves, (4) Excitation of acoustic surface waves with a grating coupled Gunn oscillator. (Author)

A semi-theoretical analysis was carried out to determine the relative importance of factors contributing to the variation of frequency with temperature of a tunable coaxial cavity gunn diode oscillator. No attempt has been made to analyse the individual effects of the solid state parameters of the gallium arsenide gunn diode itself. A method of automatically compensating the negative variations of frequency with temperature of both the gunn diode and its package and the coaxial resonant cavity was devised. These experiments also emphasise the need for producing gunn diodes having reproducibly constant variation of frequency with temperature (df/dT). (Author)

The report deals with the progress made during the second quarterly period of a solid state microwave oscillator and amplifier research and development program. Discussed first is the progress on Gunn effect research. Work on the following specific topics is reviewed: high efficiency studies of LSA oscillators; some harmonic properties of an LSA oscillator; LSA circuit studies; operation of multiple LSA diodes; a varactor tuned Gunn oscillator; and a Gunn effect amplifier. The progress made on a parallel program on avalanche diode devices is also described. The following specific topics are reviewed: performance characteristics of subharmonically locked IMPATT diode oscillators; IMPATT efficiency and average power improvement resulting from second harmonic tuning; harmonic properties of avalanche diode oscillators; integrated IMPATT and TRAPATT oscillators; high-frequency high-efficiency avalanche oscillations; avalache device calculations in the anomalous high-efficiency regime; higher average power TRAPATT oscillator studies; and measurements of IMPATT diode parameters at microwave frequencies. Finally, the progress made on the studies of solid state materials for microwave devices are reported. The topics include: ion implantation and diffusion; vacuum epitaxial growth in silicon; microwave avalanche oscillator fabrication from bulk material; and epitaxial growth and performance of gallium arsenide. (Author)

The objective of this program is to improve the knowledge and state of the art concerning compound semiconducting materials with particular emphasis on their use in practical devices. The program consists of three principal sections: epitaxial crystal growth; device application; and fundamental materials studies. The epitaxial crystal growth section concerns the preparation of material suitable for the device applications. The major emphasis in device application is on microwave and acoustical devices using thin film GaAs. The materials studies concern scientific aspects of crystal preparation and the properties of crystals of compound semiconductors. During the initial phase of the program, there has been significant progress on the preparation of thin films of GaAs using liquid phase epitaxial growth techniques. Initial problems concerning surface morphology and purity have been solved and wafers suitable for device fabrication are now being produced. Studies of device applications are in their initial phases. In the materials studies, the initial activity has concerned the construction of relevant apparatus and the development of specific techniques required to approach each program.

The report covers the Phase 2 portion of the program to design, manufacture and test 20 high reliability radar; AN/PPS-17 (XN-1). The report covers the period during which re-evaluation of system parameters on radar performance and testing of Gunn diode transmitters is being completed. Breadboard system integration and testing is continuing. (Author)

Electrical and photoluminescence measurements have been made on liquid epitaxial gallium arsenide irradiated at room temperature by 1.25 MeV Co-60 gamma rays. Both n- and p- type crystals with initial free carrier densities of 4 X 10 to the 15th power/cubic cm were subjected to a series of irradiations after each of which Hall measurements were made as a function of temperature from 77 to 300K. Photoluminescence measurements were made on irradiated and unirradiated crystals. Hall measurements on n-type crystals indicate the presence of imperfections having energy 0.13, 0.16 and 0.30 eV below the conductions band minimum in irradiated GaAs. The 0.13 and 0.16 eV levels are introduced during irradiation at roughly 1/2 the rate at which the compensating deep acceptors are introduced. New photoluminescence peaks detected in both n- and p-type crystals indicate energy levels near the center of the band gap which may also be produced by irradiation. Hall measurements on p-type crystals indicate the presence of imperfections having energy levels 0.059 and 0.10 eV above the valence band maximum in irradiated GaAs. The Hall measurements made on these crystals before irradiation indicate the presence of impurities having energy levels in the lower 0.20 eV of the band gap. (Author)

Carrier recombination and laser processes in semiconductors, mainly GaAs, are described. Measurements on GaAs over a wide doping range are reported. The electron-hole-lattice interaction and its 16meV reduction of the laser photon energy in GaAs is ascribed in large part to electron-electron interaction. Laser operation of p-n junctions in GaAs doped with amphoteric impurities is demonstrated. Optical pumping with a Ga(AsP) laser diode has been used to excite photoluminescence and laser operation of n+/n/n+ layered structures, and to perform spectroscopic studies on Gunn oscillator wafers. A method is described for coupling laser beams into thin structures (about one micrometer) and for easy coupling of optical signals between various thin structures. (Author)

The theoretical analysis of gallium arsenide avalanche transit time devices has been presented. This analysis has established the criteria for optimum design of oscillators and amplifiers and has led to the application of these devices in Army communications and radar systems. (Author)

A research and development program on high power cw transferred electron oscillators (TEOs) in X-band is described. The objectives of the program were: (a) to obtain a power output of 500 mW, (b) a minimum operating life of 1500 hours, and (c) to design and fabricate a metal-ceramic microstrip circuit for TEOs. All these objectives were successfully met. The highest power output obtained from a single device was 700 mW at 8.75 GHz with an efficiency of 2.7%. Twenty-five devices with power outputs ranging from 50 mW to 670 mW were delivered to the contracting agency. This report describes the efforts on GaAs materials technology, device fabrication technology, and the device-circuit study. A preliminary study of the effect of second harmonic tuning on the dc/rf conversion efficiency is also described. The design criteria for a metal-ceramic microstrip circuit are discussed along with the details of fabrication of such circuits. A device on life test has logged over 16,000 hours with stable power output. (Author)

Although it has been known for many years that under the proper conditions an oscillator can lock to and follow an external signal of much smaller amplitude, this phenomena has not had widespread usage. The development of negative resistance solid state oscillator diodes, such as the Gunn diode, has brought about renewed interest in the locked oscillator, however. The locking characteristics of an X-Band Gunn-effect oscillator have been investigated. The theory of injection locking is discussed and the experimental work performed is described. Amplifier performance of 20 db gain with 40 MHz bandwidth and 30 db gain with 13 MHz bandwidth is reported. The advantages of the locked Gunn-effect oscillator as an amplifier for frequency modulated signals are its minimal power supply requirements, small size, low weight, and simplicity. (Author)

One object of the patent is to provide Gunn devices, or the like, electrically connected in series and thermally connected in parallel. Another object is to provide a plurality of Gunn devices having ease of fabrication. A further object is to provide a plurality of Gunn devices which operate satisfactorily when connected in series. Briefly, these and other objects of the patent are attained by providing a plurality of Gunn devices fabricated along a single layer of active semiconductor material. Corresponding ohmic contacts located on each side of the semiconductive layer overlap to define a plurality of Gunn devices which are electrically connected in series and thermally connected in parallel. If desired, the Gunn devices may be fabricated such that the plurality of devices operate in phase.

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: 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; Instabilities in germanium. (Author)

Contents: Acoustic pumping of fluids; Fuel cell research; Dielectric loss in polymers; Signal processing via surface acoustic waves; Monolithic surface wave amplifiers; Tunable Raman laser; Acoustic properties of materials, Acoustic methods for cell discrimination; Gunn effect traveling wave amplifiers; Large time bandwidth surface wave delay lines., See also report dated Jun 71, AD-730 062.

The report describes a complete system to plot automatically the output frequency and power of a microwave Gunn oscillator over a temperature range of + 100C to - 100C. The circuits constructed are described and an example of a plot of a Gunn oscillator is included. (Author)

The report covers a brief liaison visit to Japanese industrial laboratories to obtain a broad coverage of recent progress in fields such as microwaves, electron physics, computer components, semiconductors, and electron devices in general. (Author)

The report deals with the progress made during the fourth quarterly period of a solid state microwave oscillator and amplifier research and development program. Discussed first is the progress on Gunn effect research. Work on the following specific topics is reviewed: frequency control studies of LSA oscillators; some harmonic properties of an LSA oscillator; LSA circuit studies; control of silicon contamination in GaAs; a varactor tuned Gunn oscillator; and Gunn effect amplifiers. The progress made on a program on avalanche devices is also described. The following specific topics are reviewed: higher average power TRAPATT considerations; GaAs Schottky barrier IMPATT diodes; nonlinearities of IMPATT reflection amplifiers with two input signals; integrated IMPATT and TRAPATT oscillators; and high-frequency high-efficiency avalanche oscillations. Studies of an experimental Pt-n-p+ punch-through-injection Ku-band diode are reported. Finally, the progress made on the studies of solid state materials for microwave devices are reported. The topics include: ion implantation and diffusion; vacuum expitaxial growth in silicon; and ionization rates in gallium arsenide. (Author)