Abstract: In a microwave electric power receiver, a microstrip resonator having a line length 1/2 of a wavelength of a microwave to be received is notched to be split at its longitudinally central portion into two portions. A rectification diode is interposed between notched end portions of the microstrip resonator portions to be matched therewith. The diode generates a DC power.

Abstract: An antenna device shared by three different waves has a single two-stage collinear antenna constituted by half-wave dipole antennas which are adapted for a vehicle telephone signal and are stacked one upon the other. The device allows an AM-FM radio receiver to receive AM and FM broadcast signals via a first coaxial cable and a vehicle telephone transceiver to receive a telephone signal via a second coaxial cable. A first impedance converting circuit is implemented as a field effect transistor and connected to the base end of the antenna for matching the antenna and the first coaxial cable in the event of reception of the AM broadcast signal. A second impedance converting circuit matches the antenna and the first coaxial cable at the time of reception of the FM broadcast signal. The impedance converting circuits convert the input/output impedances of the AM and FM signals.

Abstract: A full duplex transponder system includes an interrogation apparatus and a transponder apparatus. The transponder apparatus includes a reception antenna for receiving an interrogation signal wave whose carrier wave is phase- or frequency-modulated with an interrogation signal, a demodulator for demodulating the interrogation signal from the interrogation signal wave received by the antenna, a rectifier for rectifying the carrier wave of the interrogation signal wave received by the antenna and outputting a DC power used as a drive power source of the transponder apparatus, a multiplier for generating a predetermined harmonic component from the carrier wave of the interrogation signal wave received by the antenna, a modulator for amplitude-modulating the harmonic component with a response signal, and a transmission antenna for transmitting a response signal wave output from the modulator.

Abstract: A microwave amplifying apparatus includes a waveguide which is shorted at one end and supplied with a TM mode or a TE mode signal, a pickup probe mounted on the waveguide for converting the signal into a TEM mode signal, and microstrip lines and field effect transistors, or amplifier elements, for amplifying the TEM mode signal. A matching device is arranged on the shorted waveguide adjacent to an incidence side with respect to the pickup probe while an input terminal of the first-stage amplifier element is directly interconnected to an output terminal of the pickup probe. The device is, therefore, free from a signal loss otherwise developed between the pickup probe and the initial-stage amplifier element. The matching device consists of three conductive rods which are spaced a quarter-wavelength distance from each other, and three lock nuts for fixing the conductive rods.