Abstract: A low cost arrangement for a millimeter wave solid state diode oscillator, hich obviates precise machining and uses a dielectric transmission line associated with a resonant cavity. Coupling and impedance matching are greatly facilitated by a conductive stripe structure on the end of the dielectric transmission line, extending into the resonant cavity of the solid state oscillator. Fine tuning is provided by a mechanical slide screw. Two layers of shielding surrounding the resonant cavity are provided by a convenient package suitable for various applications of the millimeter wave oscillator wherein leakage radiation is not permitted.

Abstract: A microwave solid state oscillator of a compact size for generating an oscillation of a highly stabilized frequency, comprising a cavity resonator having a coupling window for coupling with an external circuit, a solid state oscillation device and a dielectric resonator of a large dielectric constant and a high Q factor, characterized in that the solid state oscillation device is installed in a recess which is formed on an inner side wall of the cavity resonator and having an opening sufficiently small compared with an internal size of the cavity resonator, and the dielectric resonator is disposed in the cavity resonator in a manner to face to and to be adjacent to the opening of the recess.

Abstract: An active semiconductor device, such as a Gunn effect device, capable of operation at extremely high frequencies, fabricated in situ on a substrate that also serves as a dielectric waveguide to propagate energy from the device. In the embodiment disclosed, a Gunn effect diode is formed on a substrate of gallium arsenide (GaAs), together with a cavity region and a metalized heat sink layer permitting operation at relatively high power levels. A bias current is applied through a conductive strip and then through the cavity region to the diode, and a quarter-wave choke is provided in the conductive strip to prevent transmission of radio-frequency energy back along the strip.

Abstract: A microwave evanescent-mode oscillator comprises a length of waveguide W1 having a cut-off frequency higher than the working frequency of the oscillator together with a Gunn element G disposed within the waveguide characterized in that the oscillator comprises, spaced in sequence along the waveguide a Gunn element G post-coupled into the waveguide and spaced from a first end of the waveguide, a capacitive member C and at the other end of the waveguide an end wall formed by a diaphragm D having therein an output aperture I for coupling out energy from the waveguide.

Abstract: The millimeter and submillimeter wavelength oscillator includes a Gunn diode coupled to a hole in a ferrite image waveguide in such a way that a portion of the waveguide acts as a resonant cavity, and oscillation results. A coil surrounding the portion of the waveguide has a variable dc current applied to it to variably magnetize the waveguide and hence correspondingly vary the oscillator frequency. By applying an RF signal to the Gunn diode, the oscillator frequency can be mixed with the RF to yield heterodyne or intermediate frequencies.

Abstract: An efficient higher order mode resonant combiner in which a higher order mode accumulator cavity is adjusted to have the real part of its input characteristic impedance to be so minimized as to be less than the characteristic impedance Z.sub.o of the input circuit. When an active device is matched to this low, minimized value of cavity input impedance a mismatch results between the active device power source and the input to the combiner at undesired higher order modal frequencies. This resultant mismatch at undesired modal resonances obviates the need for mode suppression devices within the cavity which devices as taught in the prior art had detrimental effect of the efficiency of the combiner.

Abstract: The invention concerns temperature stabilized resonant microwave cavities not requiring hermetic sealing and easy to be frequency adjusted, which essentially consist of a hollow body, a tuning screw, a plug and auxiliary lateral devices for coupling to the diode as well as of a termination, and are characterized in that the hollow body is filled with amorphous quartz. This hollow body consists preferably of an internal thin cartridge or vest made of precious alloy (Invar or Super Invar) forced into the hollow room of a thick support made of less precious material (aluminum).

Abstract: A lumped element microwave oscillator is mounted on the back plate secured to a wave guide for generating electromagnetic waves which propagate through the wave guide. The oscillator includes a two-terminal solid-state device, such as a Gunn diode, which exhibits negative resistance in the microwave range, connected in circuit with a dc source and lumped elements, including a variable capacitive element. The variable capacitive element is accessible without removing the back plate from the wave guide so that the capacitance can be easily adjusted for controlling the frequency of the oscillator. The power of the electromagnetic waves which propagate through the wave guide is preferably controlled by adjusting the coupling between the oscillator and the load in two ways. The physical orientation of various lumped elements mounted on the back plate can be adjusted with respect to the plane of the E field in the wave guide for controlling the coupling between the oscillator and the load in steps.

Abstract: A solid state microwave source placed within a rectangular waveguide, whose one end is short-circuited. The microwave source incorporates a negative resistance diode system placed on the inner wider wall of the waveguide and perpendicularly with respect to the waveguide transmission direction, a resonant microband line suspended by means of a dielectric substrate, a connecting means between the diode system and the resonant line, and means for connecting to an external polarization source.

Abstract: A microwave oscillator/amplifier includes a plurality of TEM transmission lines each with a negative resistance device at one end and a lossy, matched termination at the other end. A resonant cavity is coupled to each TEM line so as to induce a parallel resonance on the lines at the region of coupling. Structural means are provided for maintaining the characteristic impedance of the TEM lines uniform along the length of said lines. Fabrication of a device in which the TEM line characteristic impedance was uniformly maintained along the line length at five times the optimum negative resistance of said negative resistance device is noted. Suggested levels of characteristic impedance are relatively low compared to prior art devices, none of which are known to attempt maintenance of characteristic impedance uniform along the length of the TEM transmission line.

Abstract: The oscillator comprises a main cavity housing a Gunn diode and auxiliary cavity branching laterally and allowing only inlet of the harmonic components.The auxiliary cavity is provided with harmonic tuning means for varying the reactance of the auxiliary cavity to the harmonic components. The load impedance seen by the Gunn diode is thus varied.

Abstract: An apparatus for characterizing a surface anomaly in an electrically conductive sample includes an oscillator with an amplifier for supplying gain to the oscillator, a feedback loop linking the input and output of the amplifier, a two port ferromagnetic resonator connected within the loop to modulate the level and frequency of oscillation of the oscillator in response to eddy currents induced in the surface of the sample by the resonator, a variable attenuator connected within the loop to adjust the power level of the oscillator, and an adjustable phase shifter connected within the loop for changing the total phase shift of the loop. A sensing circuit is operably connected to the output of the amplifier to monitor the resonance parameters of the oscillator.

Abstract: A device for connecting plural oscillators to a single output port without he use of power dividers, switches or multiplexing filters. The plural oscillators produce multiple frequencies with only one oscillator operating at a given time. The oscillators are mounted in shunt waveguide cavities along a central waveguide manifold at distances from the central waveguide manifold and waveguide end so as not to affect the operating oscillator.

Abstract: A millimeter wave source, wherein an active diode, for example an avalanche diode, forming the emitter of the source is arranged opposite to a variable capacity diode, so as to have the source frequency-modulated by varying the biassing voltage of the variable capacity diode. In this source, each diode is mounted in a "module" comprising a thermally and electrically conductive support onto which a diode is in contact by one of its electrodes, the other electrode being in contact with a metallization deposited on a thick layer of dielectric material surrounding the diode. Owing to the capacitive coupling between the metallizations of both modules, the source can be frequency-modulated with a high efficiency.

Abstract: A source of millimeter waves adjustable in power and frequency and embodied as a cylindrical waveguide one end of which is provided with a movable piston and the other end with a directive antenna generally a radiating horn. Between the ends is tapped a cylindrical waveguide branch in which slides a sub-assembly carrying a radiating module containing an oscillating diode. The position of the module affects the power and the frequency of oscillation of the source and the position of the movable piston acts on the power emitted by the radiating horn.

Abstract: A circuit arrangement for generating and stably amplifying broadband rf signals. The circuit arrangement includes a first rectangular waveguide designed for operation in a frequency range below its cutoff frequency and a second rectangular waveguide for operation at the operating frequency. An active semiconductor element is disposed in the first rectangular waveguide and a direct voltage is supplied to the semiconductor element. At least one waveguide section is provided for connecting the first and second rectangular waveguides and has the same width as the second rectangular waveguide and a height less than the second rectangular waveguide. The waveguide section matches the cross section of the first rectangular waveguide to the cross section of the second rectangular waveguide.

Abstract: In accordance with one embodiment of the invention, a microwave signal is used to modulate a laser diode and the resultant modulated light output energy from the laser diode is applied through an optical fiber waveguide to the active solid state component in a microwave oscillator circuit such that the output signal from the microwave oscillator is phase locked to the modulation carried by the light energy. The invention allows optical injection phase locking to be achieved not only at the fundamental frequency of the modulating signal, but also at various harmonics thereof; and "on-off" switching of the microwave oscillator can be controlled simultaneously with phase locking.

Abstract: A millimeter wave integrated oscillator circuit utilizing an active device uch as an IMPATT or Gunn diode device located in a metallized dielectric cavity which is an extension of a half-height rectangular cross-sectional boron nitride image guide having a metallized under surface solder bonded to a metallic substrate forming an image plane. The diode is energized by means of a bias conductor fed into the cavity through a small slot in the cavity wall. One end of the image guide terminates in the cavity, while the opposite end is tapered along its sides and terminates in a full height hollow metal waveguide section partially including the metallic substrate. The metal waveguide section, moreover, includes flanges for coupling external circuit means to the image guide to metal waveguide transition.

Abstract: A circuit capable of providing the negative resistance heart of oscillators or amplifiers in the 5-20 Gc/s frequency band, comprising a central resonant cavity and one or several peripheral exciting chambers, each containing a push-pull arrangement of two diodes for example three pairs of diodes in chambers arranged at 120.degree. from one another on a circle concentric to the central cavity. The diodes are located at the bottoms of cylindrical exciting chambers communicating with the central chamber through holes situated at the center of each push-pull arrangement. Each pair of diodes is maintained and polarized by a metallic bar which plays, with the walls of the exciting chamber, the role of an impedance transformer between the diodes and the central cavity. The metallic bar is maintained by a polarization rod penetrating the chamber through an insulating passage.

Abstract: A tunable millimeter wave frequency Gunn oscillator operates efficiently beyond the normal Gunn oscillator frequency range through the use of a second harmonic enhancement circuit. The enhancement circuit is tuned to the fundamental frequency of the oscillator and is tracked with a second harmonic circuit to provide a wide tuning range. Lumped element circuitry is used to aid in providing the wide tuning range and to facilitate adjustment and fabrication.

Abstract: Disclosed is a means for obtaining a high Q oscillator which is compact and s adapted to be readily incorporated into known forms of microwave integrated circuits, e.g. a parametric amplifier. The oscillator which for example may comprise a pump oscillator for a parametric amplifier includes efficient means for coupling to microstrip without destroying the high Q of the oscillator circuit. The negative resistance elements which may be, for example, a Gunn diode, IMPATT diode or the like is located in a resonator cavity which is a combination of radial transmission line cavity and a rectangular waveguide cavity.

Abstract: A microwave/millimeterwave oscillator includes a transferred electron device adapted to operate at a first frequency. The device is housed in a waveguide transmission line in a quarter wavelength, quasi-radial mode cavity dimensioned to enable the device to oscillate at a second frequency, higher then the first frequency.

Abstract: Apparatus for the generation and radiation of microwave radiation including a microwave oscillator having a cavity resonator directly coupled with the input of a horn resonator by way of a first apertured diaphragm. There is arranged within the horn radiator a second apertured diaphragm disposed at a distance from the first apertured diaphragm such that together with the first diaphragm it forms a filter resonator.