Abstract: A microwave tuned cavity has a strip of temperature sensitive bi-metallic material plated with silver attached at one end to the inner surface for the tuned cavity and having its other end extending at an inclined angle to the center of the volume bounded by the inner surface of the tuned cavity. The housing of the tuned cavity expands as its temperature increases, tending to cause the resonant frequency of the cavity to decrease. The strip of bi-metallic material bends slightly as the temperature increases, causing its free end to move toward the surface on which the strip is mounted. This decreases the amount of capacitive loading of the resonant signal in the cavity, tending to increase the resonant frequency caused by thermal expansion of the housing. When the temperature decreases, the free end of the bi-metallic strip moves slightly toward the center of the cavity, thereby compensating for slight thermal contraction of the walls due to the decrease in temperature.

Abstract: A microwave oven comprising a heating cavity, a controllable frequency microwave power source, a detector for detecting the intensity of the electric field in the cavity and control means for setting the microwave power source at the frequency as determined by the intensity of the electric field. The frequency at which the loaded cavity is energized is selected by the control means to store high power in the cavity. The dimensions of the cavity are selected for generating only the TE.sub.m0p mode at the frequency of the microwave power source which is limited to 915.+-.13 MHz, where 0 is the mode index in the direction of the height of the cavity.

Abstract: A cylindrical ENDOR cavity with RF saddle coils disposed axially is symmetrized by shielding the end portions of the saddle coil within cylindrical conducting rings or cylinder portions whereby the Q of the cavity is substantially enhanced.

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: An electronically tunable YIG microwave filter with a two-piece housing is described. The two-piece housing makes possible the fabrication of small holes deep within the filter housing for mounting the filter components. This filter uses the center conductors of its input and output coaxial cables as input and output coupling loops.

Abstract: First and second directional couplers each having a primary arm, a through arm and two secondary arms with a resonant circuit constructed to include the two secondary arms of each directional coupler. The directional filter forms a four port device with signals of a first frequency being applied to the first port and coupled to the fourth port by the resonant circuit, and signals applied to the third port being conveyed directly to the first port. Signals other than those at the first frequency are not coupled between the first and fourth ports.

Abstract: A resonant structure, for supporting electromagnetic (EM) oscillations win a frequency range of approximately 10 GHz to 1000 GHz, and whose resonant properties are controlled by light. The structure includes an interaction material for absorbing light and forming a plasma of electron-hole pairs within the material. Kinetic and potential energy, which are stored in the EM oscillations within the resonant structure, change as a result of the plasma and shift the frequency of the oscillations.

Abstract: A compact low loss microwave filter is disclosed which utilizes an angular section of a right circular cylindrical cavity at the resonance structure excited in the circular electric TE.sub.0mn mode. The individual sectors may be electrically or magnetically coupled through common walls to obtain various filter characteristics.

Abstract: A high frequency filter for frequencies higher than the VHF band comprising at least one resonator has been found. Each resonator comprises a conductive housing, an inner conductor one end of which is fixed at the bottom of the housing and the other end of which is free standing, a cylindrical dielectric body surrounding said inner conductor, and the diameter of the dielectric body is approximately four times as large as that of said inner conductor.

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 mode filter apparatus for preventing unwanted modes in a multi-moded structure utilizing a radial plurality of resonant slots on the bottom of the filter cavity. The top of the filter cavity includes a variable height center section to provide mode selectivity in cooperation with the resonant slots.

Abstract: A resonant cavity such as a diplexer filter and a coaxial resonator, for example, wherein its interior resonant cavity structure is packed with a powdered polytetrafluoroethylene material to prevent arcing within the resonant cavity structure due to the multipacting phenomenon.