Hitachi, Ltd.

Nissan Motor Company Limited

Hitachi Heating Appliances Co., Ltd.

Katsuhiro Kimura

Akira Endo

Yoichi Kaneko

Kenji Sekine

Yukitsugu Hirota

Hiroshi Morozumi

Takanori Shibata

Keiro Shinkawa

Jiro Takezaki

Mitsuru Watanabe

Takahiko Tanigami

Itsuo Kikuchi

Tadashi Funamizu

Chiuichi Sodeyama

A Doppler radar type speedometer capable of speed detection without a detection error comprises a Doppler radar signal processing circuit which includes a random access memory. In the circuit, the levels '1' of Doppler radar pulses of individual frequencies are added to the contents of the random access memory which stores the resultant data therein, so that the pulse width can be detected which is provided by the number of levels '1' at the most significant bits of the results stored in the addresses corresponding to a n/2-th output pulse signal of a predetermined number n of output pulse signals arranged in order of pulse widths.

Doppler radar type speedometer

A microwave alcohol fuel sensor comprises a microwave oscillator, a microwave receiver, and a microwave transmission circuit connected to the oscillator and the receiver. The microwave transmission circuit comprises a dielectric substrate and, a strip line mounted on the substrate so that microwaves leak from the substrate to an alcohol gasoline fuel, and the microwaves attenuate by alcohol dielectric loss, whereby output voltage from the receiver corresponds to alcohol content rate. The dielectric substrate is formed tubular so that a constant amount of the fuel is fed the sensor.

Microwave alcohol fuel sensor

Ignition system for internal combustion engine in which combustion chambers in an internal combustion engine are shaped in such a manner that a microwave resonance easily causes a plasma discharge, microwaves are supplied from a microwave oscillator through respective coaxial cables to all the combustion chambers so that the combustion chambers resonate whenever the microwave power is injected, or so that when the combustion chambers reaches a resonatable condition, is the microwave power injected into the combustion chambers from the microwave oscillator; thereby causing plasma discharge to occur in the combustion chambers.

Ignition system for internal combustion engine

A Doppler radar speed sensor including an antenna section and a sensor section is mounted on the underside of the automobile undercarriage. A recess for accommodating the Doppler radar speed sensor is formed in part of the underside of the automobile undercarriage within a rectangle surrounded by the wheels, and the Doppler radar speed sensor is mounted fully within the recess. This structure prevents the sensor from being damaged in an unfavorable environment or external vehicle devices from being interfered with by the leakage of the unrequired radar wave. For size reduction, the Doppler radar speed sensor is provided with a metal casing integrated with a slotted waveguide antenna. The slot array of the antenna is formed in one side of the metal casing, so that the metal casing, makes up part of the slot array antenna.

Doppler radar mounting structure for motor vehicles

In a Doppler radar system for measuring the velocity of a vehicle, such as an automobile, in order to lessen interference with external electric wave appliances, such as radios and televisions, caused by transmitting microwaves, one of the higher harmonics generated from a mixer diode driven by the fundamental waves of a local oscillator is selected by a filter for transmission and is used as the transmission output wave, whereby the power of the transmission waves is remarkably reduced in comparison with the mixer driving power.

Short-range doppler radar

There is disclosed a microwave integrated circuit device which comprises a waveguide circuit, a short-circuiting member serving as a short-circuiting plane and having a groove in the short-circuiting plane, means for varying the effective dimensions of the groove which have effect on microwave circuit components, a microwave integrated circuit formed on an insulating substrate so disposed as to cover the groove, and a semiconductor element disposed on the microwave integrated circuit to convert the microwave signal in the waveguide circuit into a selected one of a d.c. and a low-frequency, whereby the conversion efficiency may be increased by setting the peak position of the output level characteristic of the device at a desired frequency within a certain frequency band.

Microwave integrated circuit device for transmission/reception of a

A microwave oven having special form of a microwave energy radiation arrangement. In order to heat uniformly materials to be cooked, the microwave energy radiation arrangement includes a rotatable conductive rod extending into an oven chamber through a hole located substantially in the center of one oven chamber wall, a rotating conductive arm having one end fixed on the rod so as to extend transversely thereto, and a conductive plate having the center thereof coincident with the axis of the rod and arrayed such that the rotating arm is interposed between the one wall and the conductive plate. Openings for radiating microwave energy into the oven chamber are formed at the periphery of the conductive plate.

Microwave oven

Microwave heating apparatus comprising a fan beam radiator exhibiting a pattern of microwave radiation which is concentrated in the angular direction and less concentrated in the radial direction with respect to a shaft set substantially at the center of an oven and rotating a microwave beam and an article to-be-heated relative to each other, thereby to uniformly heat the article by applying the rotating beam.

Microwave heating apparatus

A mixer circuit in which a high frequency signal and a local oscillation signal are applied to two ports respectively of a rat-race having four ports, and the other two ports are connected at one end thereof to grounded diodes respectively. An intermediate frequency signal is derived from a filter connected to a circular loop in the rat-race. The distances of the two arcuate transmission paths between the connection point of the filter and the diodes are selected to be equal to each other, and the two arcuate transmission paths between the connection point of the filter and the high frequency signal input port are selected to have a distance difference corresponding to one half the wavelength of the high frequency signal.

Mixer circuit

A temperature compensated dielectric resonator device is composed of a dielectric resonator element mounted on a micro-integrated circuit (MIC) plane. A screw is provided for manually regulating the frequency of the device and a supporting member supporting the screw is disposed in vicinity of the element. The supporting member dimensions and materials are predetermined, so that the screw may be held at such a position that it compensates for a resonant frequency shift caused by thermal expansion.

Growing community of inventors

Tokyo, Japan

Katsuhiro Kimura