Abstract: A cooking appliance employing microwaves is provided. The cooking appliance employing microwaves includes a first microwave generating unit for generating and outputting a plurality of microwaves so as to heat an object in a cavity; and a second microwave generating unit for generating and outputting microwaves differing from those of the first microwave generating unit, so as to heat the object in the cavity. In this way, operating efficiency can be improved.

Abstract: There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to double the effective frequency of a ceramic coaxial resonator is to couple each end of a resonator to a Colpitts oscillator, the oscillators being balanced and out-of-phase by 180°. During operation, the resonator is effectively divided in half with a virtual ground forming in the center. This allows a single resonator to operate as two resonators of half the original size. Hence, the oscillation frequency for each of these balanced oscillators is doubled when compared to the frequency of similar oscillators that have separate ceramic coaxial resonators of similar size. If this technique is further implemented within a push-pull design tuned to the third harmonic, the output oscillation frequency becomes six times that of an oscillator using a separate ceramic coaxial resonator of similar size.

Abstract: There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to double the effective frequency of a ceramic coaxial resonator is to couple each end of a resonator to a Colpitts oscillator, the oscillators being balanced and out-of-phase by 180°. During operation, the resonator is effectively divided in half with a virtual ground forming in the center. This allows a single resonator to operate as two resonators of half the original size. Hence, the oscillation frequency for each of these balanced oscillators is doubled when compared to the frequency of similar oscillators that have separate ceramic coaxial resonators of similar size.

Abstract: A push—push oscillator is formed by (a) a resonator circuit including a transmission line having one-half wavelength and both ends of the line being left open, and a capacitance for frequency control coupled to the transmission line in parallel, and (b) two oscillators electrically identical to each other and their input sections being coupled to both the ends of the transmission line. Further, this oscillator can take out an output signal of even-order-harmonics from a midpoint of the transmission line in a transmitting direction as well as take out two fundamental waves from respective output sections of two branch oscillators. This push—push oscillator operating with a high frequency is downsized and simplified from a conventional one. Its phase-noise-characteristics and noise immunity are also improved.

Abstract: There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to double the effective frequency of a ceramic coaxial resonator is to couple each end of a resonator to a Colpitts oscillator, the oscillators being balanced and out-of-phase by 180°. During operation, the resonator is effectively divided in half with a virtual ground forming in the center. This allows a single resonator to operate as two resonators of half the original size. Hence, the oscillation frequency for each of these balanced oscillators is doubled when compared to the frequency of similar oscillators that have separate ceramic coaxial resonators of similar size. If this technique is further implemented within a push-pull design tuned to the third harmonic, the output oscillation frequency becomes six times that of an oscillator using a separate ceramic coaxial resonator of similar size.

Abstract: A radio-frequency amplifier includes at least two double-ended electron discharge devices in coaxial-type, radio-frequency cavity-resonator circuits. Each discharge device has a discharge region so that the amplifier comprises a plurality of longitudinally spaced-apart, electrically connected discharge regions. Each of the discharge regions has a cathode with an anode circumscribing the cathode. At least one grid electrode is disposed between the cathode and the anode. A coaxial input transmission line is loop-coupled to an input cavity-resonator circuit and a coaxial output transmission line is loop-coupled to an output cavity-resonator circuit.

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 broad-band cavity-tuned transistor oscillator includes a field effect device having capacitive feedback from source to drain and having a gate capacitively coupled to a cavity for producing an output signal that is frequency selectable according to cavity resonance, which resonance is determined by translation position of a mechanical tuning plunger coupled to the cavity and the degree of capacitive feedback.

Abstract: A high power output push-pull microwave oscillator utilizing a plurality of tuned coaxial circuits each mounting a diode at each of two extremities and each being coupled to an output cavity of resonant frequency, f.sub.o, equal to the operating frequency. An equal plurality of second cavities, also resonant at f.sub.o are coupled to bias lines one-fourth wavelength from each of the plurality of tuned coaxial circuits to reflect a short circuit across a tee junction built into the center conductor of each coaxial circuit at the resonant frequency, f.sub.o, when the diodes are in a push-pull or out-of-phase operating mode. The short circuit is removed when the diodes operate in an in-phase mode and the resultant losses effectively suppress the in-phase mode of operation.