Matsushita Electric Industrial Co., Ltd.

Haruyoshi Endo

Mitsuo Makimoto

Sadahiko Yamashita

Morikazu Sagawa

Ko Kikuchi

Makoto Hasegawa

Suguru Fujita

Hiroyuki Yabuki

Kouei Misaizu

Fumio Fukushima

Koji Mizuno

A first responder for transmitting an identification signal in response to a microwave interrogation signal comprises an electric power receiving circuit for receiving the interrogation signal to produce a dc power, having a microstrip line antenna having a trapezoid shape whose upside has a width from 1/2 to 1/4 of a wavelength, and a rectifying circuit. The rectifying circuit may be modified. A second responder comprises an electric power receiving circuit having a microstrip line antenna from the received microwave signal, a power supplying circuit for supplying a dc power in the vertical and horizontal positions of the responder against a polarizing plane of the microwave signal, an identification signal generation circuit for transmitting an identification signal through the antenna with given polarization plane by detecting the responder attitude. A third responder receives a microwave signal circularly polarized or polarized in vertical and horizontal directions and transmits the identification signal in either of vertical or horizontal directions according to the received microwave intensity in both directions.

Electric power receiving circuit and responder for automatic vehicle

A push-push oscillator comprises: a resonator having a transmission line and a capacitance connected to the transmission line in parallel; an oscillator for producing two outputs having an antiphase relation therebetween in response to the resonator; and a differential signal producing circuit for producing a differential signal in accordance with difference between these two outputs. These outputs can be obtained from the resonator. The transmission lines comprise strip line or microstrip line which is curved to form an open loop. The transmission line may be made of a dielectric material and is curved to form an open loop whose both ends are connected to a capacitance. The resonator may further comprise two second transmission lines, each provided to an end of the transmission line, these two second transmission lines facing each other with a given distance therebetween, the distance and length of the second transmission lines being determined such that necessary capacitance is provided. Impedance of each portion of the resonator is determined to miniaturize the resonator. The differential signal producing circuit comprises a balanced to unbalanced converting circuit.

Push-push oscillator using a transmission line resonator and

A resonator having a strip line, the strip line comprising: a first portion forming an open loop; and two second portions, each provided to each end of the first portion, the second portions facing each other with a given distance therebetween, the distance and length of the second portion being determined such that necessary capacitance is provided. The capacitor is provided instead of a discrete capacitor for saving space and for reducing dielectric loss therein. A second resonator further comprises second and third capacitor having a semicircle strip-line patterns for providing capacitances between ends of the first portion and grounded planes which decrease the resonance frequency so that size of the second resonator are reduced. A third resonator also comprises the first capacitor, but arranged outside of the first portion. Capacitance of the first capacitor can be increased by teeth provided to the second portions. A filter comprises plural third resonators so arranged that coupling between the resonators is obtained by one selected from magnetic-field coupling through the first portions, electromagnetic-field coupling through first and second portions, and electric-field coupling through second portions.

Resonator and a filter including the same

There is disclosed herein a millimeter-wave/submillimeter-wave oscillator comprising a mirror and a diffraction grating so as to form a Fabry-Perot type resonator. The mirror, being a concave mirror or a plane mirror, and the diffraction grating are disposed in facing and spaced relation to each other. The diffraction grating has a plurality of channels extending in a direction normal to a surface of the mirror so that the oscillator has a comb-like configuration. A plurality of oscillation elements are mounted on portions within the channels of the diffraction grating.

Millimeter-wave/submillimeter-wave oscillator

A mixer for outputting an intermediate frequency signal as the result of mixing of a radio frequency signal and a local oscillator signal which are inputted into the mixer. The mixer comprises a balanced-to-unbalanced conversion circuit and a bridge-coupled diode circuit and the balanced-to-unbalanced conversion circuit is constructed of first and second rat race circuits, one being for the radio frequencey signal and comprising a first ring-shaped line and the other being for the local oscillator signal and comprising a second ring-shaped line. The mixer is arranged to include a substrate having first and second pattern-forming surfaces and the first ring-shaped line of the first rat race circuit is formed as a pattern on the first pattern-forming surface of the substrate and the second ring-shaped line of the second rat race circuit is formed as a pattern on the second pattern-forming surface. The bridge-coupled diode circuit is positioned on the first pattern-forming surface thereof and inside the patterned first ring-shaped line.

Mixer with rat race circuit

A coaxial dielectric resonator for VHF and/or UHF band comprising a generally cylindrical dielectric having inner surface and outer surface. The inner and outer surfaces of the dielectric are respectively covered by outer and inner conductors and these conductors are connected at one end of the dielectric. An adjusting screw for adjusting resonance frequency is provided at the other end of the dielectric which is covered by a lid while holding a gap between the adjusting screw and the lid. A microwave filter using a plurality of the coaxial dielectric resonator is further described.

Frequency-adjustable coaxial dielectric resonator and filter using the

A band-stop filter for VHF-UHF band comprises at least three series resonance circuits and at least two transmission lines each connected between the series resonance circuits. One of the transmission lines, which is connected to the input terminal of the band-stop filter, has an electrical length which is shorter or longer than the quarter wavelength of the center frequency of the stop band by more than 20 but less than 50 percent. When a band-stop filter comprises four transmission lines, one of the transmission lines, which is connected to the output terminal of the band-stop filter, has the same length as the transmission line connected to the input terminal. With this arrangement, the band-stop filter exhibits a sharp attenuation characteristic in a frequency range below or above the center frequency. Other transmission lines, which are not directly connected to either the input terminal or the output terminal, may have a length which is shorter or longer than the quarter wavelength by 5 to 20 percent so as to provide a sharper attenuation characteristic.

Band-stop filter for VHF-UHF band

In a coaxial filter arrangement having a plurality of coaxial resonators each having a bottomed metallic cylinder interposed between a dielectric plate and one end of a center conductor of each resonator, the peripheral wall portion of the metallic cylinder is received in the bore of an outer conductor having an open end and a closed end connected to the other end of the center conductor. In one embodiment, the bottom of the metallic cylinder has a convex portion at its center so that the bottom center projects outwardly. In another embodiment, an annular metallic member is interposed between the dielectric plate and the outer surface of the flat bottom of the metallic cylinder. Since the distance between bottoms of metallic cylinders of adjacent resonators is made large with this arrangement, influence due to leakage flux of electromagnetic field is small, while stray capacitance is negligibly small, thereby providing a filter having high performance and low loss.

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Zama, Japan

Haruyoshi Endo