Nippon Soken, Inc.

Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Masao Kodera

Kunihiko Sasaki

Shigeyuki Akita

Seishin Mikami

Sigeyuki Akita

Yasuhisa Yoshino

Eturo Yasuda

Jyunshi Utsu

Tadashi Hattori

Akira Kuno

Takeshi Tanaka

Hiroshi Mizuno

Seizi Huzino

Tatsuo Teratani

Takashi Sakurai

Hiroyuki Sakakibara

Hisatoshi Ohta

Hajime Ito

Tsuyoshi Maeno

Junshi Utsu

Keiichiro Toyama

Junsi Utsu

A high-frequency amplifier has a semiconductor element for amplifying a high-frequency signal, an input matching circuit connected to an input side of the semiconductor element, and an output matching circuit connected to an output side of the semiconductor element. A stabilizing circuit is connected to at least one of a signal input path between the input matching circuit and the semiconductor element, and a signal output path between the semiconductor element and the output matching circuit. The stabilizing circuit includes a first element having a first end which is short-circuited with respect to a high frequency, a parallel resonant circuit connected in series with a second end of the first element and performing parallel resonance at an operating frequency of the high-frequency amplifier, and a second element connected to a side of the parallel resonant circuit which is opposite to the first element. Values of the first element and the second element are chosen so that an admittance of the high-frequency amplifier which occurs at a frequency of possible oscillation of the high-frequency amplifier will be within a constant-conductance circle in a Smith chart which denotes a stable condition of the high-frequency amplifier.

Circuit for stabilizing RF amplifier

Series reactance elements constituted by capacitors are connected to an input side corresponding to the gate electrode of an amplifying FET and an output side corresponding to the drain electrode of the amplifying FET, respectively. Parallel variable reactance circuits are connected to the input and output sides, respectively. Each variable reactance circuit includes a FET, where the source electrodes of the FET are connected to the input and output sides through MIM capacitors, respectively. Additionally, drain electrodes of the FETs are grounded through inductive loads which are constituted by spiral inductors, respectively. The source electrodes of the FETs constituting the variable reactance circuits are grounded through choke coils, respectively. The drain electrodes of the FETs receive control bias voltages through the choke coils, respectively. In this case, each of the resistive components of the spiral inductors is set to have a value which can cancel the negative resistive component of the corresponding FET.

Variable reactance circuit for microwave or millimeter wave band and

The invention relates to a transponder for a vehicle identification device in which a radio wave including vehicle information returned from transponders provided in a vehicle is received by an interrogator. The vehicle transponder receives a query radio wave and uses a detection device to generate a previously memorized coded signal train in response to a received wave. The coded signal train varies an amount of bias voltage of the detection device so that a reflection coefficient of the detection device is varied to modulate the reflection wave of the query radio wave and the modulated wave is transmitted back to the interrogator.

Transponder for vehicle identification device

A system for supplying energy to a microrobot disposed within a piping system for inspection or repair. The system comprises a microwave transmission section for transmitting as energy a microwave to the robot within the piping system. The microwave transmission section is arranged to transmit the microwave having a frequency equal to or higher than a frequency determined in correspondence with an inner diameter of a pipe of the piping system in which the microrobot is disposed. The microrobot receives the transmitted microwave to convert it into an electric power for operation. This arrangement can ensure a smooth operation of the microrobot within a small-sized pipe because the microrobot is not connected to the transmission section through an electric connection.

Energy supply system to robot within pipe

A Doppler radar speed detecting method in which periods of a Doppler signal are measured within a predetermined sampling time, and frequency data corresponding to the thus obtained period data are obtained. Upper and lower limit values are set based on the previous Doppler frequency F(k-1). The frequency data are compared with these limit values. Frequency data within a low region lower than the lower limit value, and intermedaite region between the lower and upper limit values, and a high region higher than the upper limit value are respectively counted in accordance with the comparison. Further, for the frequency data between the lower and upper limits, an integrated value of differences between these data and the previous Doppler frequency is obtained. From these integrated value and the numbers of frequency data, the change from the previous to the present Doppler frequency is calculated. By adding this change and the previous Doppler frequency together, the present Doppler frequency is obtained.

Doppler radar speed detecting method and apparatus therefor

In a planar array antenna in which radio frequency power fed by a feeder line is radiated from a plurality of radiation elements disposed in a planar state on one surface of a dielectric substrate on the other surface of which the feeder line is disposed, the feeder line has a first feeder part and a second feeder part. The first feeder part is spaced apart by a predetermined distance from the marginal contour of one of the radiation elements in the planar direction of the dielectric substrate, while the second feeder part is located within the width of the marginal contour of another one of the radiation elements and directly beneath the latter radiation element, and the second feeder part is divided into two parts with respective ends thereof confronting each other, the power coupling coefficient between the second feeder part and said another one radiation element is selected to be larger than that between the first feeder part and said one of the radiation elements, thereby making the planar array antenna operate with high radiation efficiency and small side lobes.

Planar array antenna

A microwave probe has a cylindrical support made of stabilized zirconia being excellent in heat insulation, and the cylindrical support is threadably installed at a partitioning wall to partition an atmosphere of high temperature. The support is provided at the center with a through hole, and an antenna for transmitting or receiving microwave is installed at one opening of the through hole positioning at outside of the partitioning wall, and a metal ring member is installed at other opening of the through hole positioning within the partitioning wall. The transmitting and receiving antenna and the ring member are fixed to respective openings by a ceramic adhesive which is filled in the through hole and excellent in heat insulation. A part of the ring member projects in the atmosphere. A rotary body breakage detecting apparatus has the microwave probe installed at a cabinet wall to cover a wing body rotating in an atmosphere of high temperature, and a microwave oscillator and a microwave detector are connected to the probe through a circulator. A breakage detecting circuit is connected to the microwave detector. The breakage detecting circuit detects that peak value of the receiving signal outputted from the detector (the signal pulsating with rotation of the wing body) varies beyond a prescribed range, and generates signal informing the breakage of the wing body.

Microwave probe and rotary body detecting apparatus using the same

An apparatus capable of sensing sudden approach of a succeeding vehicle and emitting an alarm, while being free from malfunction that may otherwise be caused by the noise from the succeeding vehicle which has approached at a normal speed and stopped in the proximity. The sensing apparatus includes a transmitter disposed in a rear bumper of a vehicle for transmitting ultrasonic waves toward a succeeding vehicle; a receiver disposed in the rear bumper for receiving the ultrasonic waves reflected from the succeeding vehicle; a circuit for detecting the approach speed of the succeeding vehicle from the difference between the frequencies of the reflected waves and the transmitted waves, and generating an alarm signal when the detected approach speed has exceeded a predetermined value; a circuit for detecting the approach distance of the succeeding vehicle at a normal speed from the signal strength of the reflected ultrasonic waves, and interrupting the action of the ultrasonic transmitter and receiver when the detected distance has become shorter than a predetermined value; and an alarm activated in response to the alarm signal and giving a warning of danger to drivers of both the apparatus-installed vehicle and the succeeding one.

Vehicle approach sensing apparatus

A rear monitor system for an automotive vehicle comprises a sensor secured to a vehicle door located on one side of the vehicle and adapted to be operated by a vehicle occupant when leaving the vehicle, the sensor generating a signal indicating that the occupant is going to leave the vehicle. A control unit is responsive to the signal from the sensor for transmitting radiant energy in a rearward direction to detect a reflection from an object approaching the vehicle from behind at a speed higher than a predetermined value. Further provided is a safety device which is responsive to the detected reflection for preventing the vehicle occupant from opening the door.

Rear monitor system triggered by occupant leaving the vehicle

An ultrasonic transducer comprises a cylindrical housing embedded within a rear bumper of a vehicle and opening backward, a reflecting plate having a parabolic reflecting surface provided within the cylindrical housing along a closed end thereof and facing an open end thereof, and an ultrasonic vibrator provided in an upper wall of the housing at the focus of the reflecting plate for emitting and receiving ultrasonic waves. The ultrasonic transducer transmits ultrasonic waves behind the vehicle and receives ultrasonic waves reflected from an obstacle. The ultrasonic transducer further comprises a projecting member provided on the inner wall of the housing along the open end thereof for dispersing and cancelling the ultrasonic waves entering the housing at angles with respect to the axis of the housing. The projecting member has a smoothly curving cross section having a radius of substantially one fourth to five times the wavelength of the ultrasonic waves emitted by the ultrasonic vibrator.

Ultrasonic transducer

An apparatus for detecting obstructions behind a vehicle, employing ultrasonic waves is disclosed. The apparatus comprises an ultrasonic transmitting and receiving device disposed on the rear portion of the vehicle, an electric motor for rotating the transmitting and receiving device at a constant velocity, an angle sensor for detecting the rotating angle of the transmitting and receiving device and a sonar circuit for emitting ultrasonic waves through the transmitting and receiving device at predetermined rotating angles, receiving ultrasonic waves reflected from obstructions through the transmitting and receiving device at predetermined rotating angles and measuring the distance to the obstructions from the time taken from the transmission to the reception of the ultrasonic waves. According to the apparatus of the present invention, the distances to obstructions in every region behind the vehicle can be accurately and easily measured by rotating a single transmitting and receiving device by means of the electric motor at a constant velocity.

Apparatus for detecting obstructions behind vehicle

A diesel smoke meter which uses micro-waves to detect the density of black smoke contained in the exhaust gas discharged from the diesel engine through an exhaust pipe. A micro-wave transmitting device is coupled to the exhaust pipe and transmits micro-waves into the exhaust pipe. Micro-waves transiting the exhaust pipe are attenuated by the black smoke in the exhaust gas. A micro-wave receiving device receives the attenuated micro-waves and provides a received signal which varies in accordance with the signal level of the attenuated micro-waves. A measuring device receives the received signal and provides an output indicative of the density of black smoke in the exhaust gas.

Diesel smoke meter

A high frequency current inducing apparatus for inducing high frequency current in a wiring harness of an instrument to be examined without the necessity of detaching the wiring harness from the instrument. A high frequency current inducing chamber is connected to a high frequency oscillator for inducing the high frequency current in the wiring harness of the instrument to be inspected, and a terminator is connected to the high frequency inducing chamber. The chamber includes an outer conductor and an inner conductor fixed at a predetermined position inside the outer conductor. The outer conductor has two inserting holes for insertion of the wiring harness along the axis of the chamber between the two conductors. The outer conductor can be separated along a plane including the two inserting holes. Once separated, the wiring harness of the instrument to be inspected can be inserted along the axis of the chamber without detaching the wiring harness from the instrument.

High frequency current inducing apparatus

An obstacle monitoring device for the rear of a vehicle comprising a plurality of ultrasonic obstacle detectors which are operated sequentially at a predetermined time interval, and an electronic monitor for supplying the obstacle detectors with their operational timing sequences at the predetermined time intervals and for determining distance information for each detector based on the changing pulse width of electric currents for each of the obstacle detectors within a particular time interval, which pulse widths correspond to the distance between an obstacle and the rear of the vehicle. A single transmission line connects the obstacle detectors with the monitor so that the number of wires in a wire-harness is reduced between the obstacle detectors (outside the vehicle) and the monitor (inside the vehicle).

Obstacle detecting device for vehicles

An ultrasonic wave conversion apparatus comprises electrodes, a support member for supporting the electrodes, a vibrator secured to the support member by a securing member, and a moving diaphragm fixed to the vibrator by a fixing member. The surface of portions of the electrodes, the vibrator, the moving diaphragm and the fixing member are coated with an insulating film of a predetermined thickness. The coating with this insulating film provides the apparatus with an excellent insulating and anticorrosive property and further an excellent damping characteristic for the vibration of the vibrating members of the apparatus.

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Okazaki, Japan

Masao Kodera