Hitachi, Ltd.

Nissan Motor Company Limited

Hitachi Denshi Kabushiki Kaisha

Hitachi Heating Appliances Co., Ltd.

Yagi Antenna Co., Ltd.

Yoichi Kaneko

Kenji Sekine

Katsuhiro Kimura

Akira Endo

Takashi Takeuchi

Keiro Shinkawa

Eiichi Hase

Yukitsugu Hirota

Akira Matsumura

Yukinari Fujiwara

Mitsuru Watanabe

Takahiko Tanigami

Itsuo Kikuchi

Mitsuo Toya

Nobuo Sekiguchi

Tadashi Funamizu

Atsushi Kaise

Haruhiko Funaki

Chiuichi Sodeyama

Naoya Hirohara

Iichi Wakou

Hisato Owatari

Hiroshi Kasahara

A planar microstrip array antenna with a beam tilt, which comprises a plurality of pairs of circularly polarized wave radiating elements, the orientation angles of the two radiating elements in each pair being different by a predetermined angle within the plane of the planar antenna. The antenna further comprises a feed line for supplying electric power to the radiating elements. The feed line is provided with a plurality of pairs of terminal feeding portions which diverge corresponding individually to the pairs of circularly polarized wave radiating elements. The paired feeding portions are equal in electrical length. Since the respective orientation angles of the paired radiating elements are different, a phase difference is produced between the radiating elements, thus providing a beam tilt. Since no phase shift portion for producing a phase difference is formed between the paired terminal feeding portions, the configuration of the feed line is simple.

Microstrip array antenna

Disclosed is a microwave solid-state amplifier arranged such that a plurality of amplifier units are used in combination of a radial cavity resonator so as to perform power dividing/combining, and that in order to make the microwave solid-state amplifier capable of performing a wide band operation and have less circuit loss, a coupling portion between the radial cavity resonator and each of the amplifier units is formed such that a loop-like conductor constituted by a stripline forming an input/output portion of the amplifier unit is removably inserted through a slot formed in a side wall surface of the cavity resonator.

Microwave solid-state amplifier

A Doppler radar wherein, in order to measure the ground speed of an automobile, microwaves are radiated to the ground and the Doppler shift of reflected waves from the ground is detected, characterized in that to the end of avoiding a malfunction ascribable to an external microwave interference, when the differentiated output of the Doppler radar is greater than a threshold value, the frequency of the microwaves of the Doppler radar is controlled so as to prevent the microwave interference from taking place.

Ground-speed Doppler radar for vehicles

A dielectric heating device for heating a dielectric sandwiched between a pair of electrodes is disclosed in which an oscillation circuit is made up of the above-mentioned electrodes, a coil connected in series with the electrodes, a first capacitor connected in parallel with a series circuit made up of the electrodes and the coil, another series circuit connected in parallel with the first capacitor and made up of second and third capacitors and a field effect transistor having source and drain electrodes connected respectively to one and the other electrodes of the second capacitor and a gate electrode connected to a junction point for connecting the first and third capacitors.

Dielectric heating device

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

A microwave integrated circuit device for use in the transmitting and receiving portion of a Doppler speedometer utilizing microwaves. In order to keep the transmitting power low and the receiving sensibility high, a microwave integrated circuit plate in which a transmitting antenna line and lines for connecting mixer diodes therewith are arranged at right angles is mounted within a rectangular waveguide and in the vicinity of a short-circuit plate of the waveguide in a manner to lie at right angles with the electric field of the waveguide.

Transmit/receive microwave circuit

A microwave integrated circuit device for reception wherein a microwave integrated circuit substrate is mounted on a short-circuited plane of an inner surface of a waveguide, a rectangular groove is provided in the short-circuited plane, and a mixer diode is arranged astride the groove.

Microwave integrated circuit device

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

In a radio station system utilizing multi-channel transmission and reception frequencies of the type comprising a transmitter and a receiver wherein the frequency difference between the transmission and reception frequencies is made to be equal to an intermediate frequency, there is provided a source of multi-frequency signal which determines the multi-channel transmission and reception frequencies. The output of the multi-frequency signal source is utilized directly as a local oscillation signal of the receiver and the frequency of the output of the multi-frequency signal source is shifted by a modulated wave having a frequency twice the intermediate frequency and the frequency shifted output is utilized as the transmission frequency.

Radio station system

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

Tokorozawa, Japan

Yoichi Kaneko