Nec Corporation

Japan Aviation Electronics Industry, Limited

Nippon Electric Co., Ltd.

Nippon Rikagakuyakuhin Company, Ltd.

Yoshiharu Tamura

Takao Suzuki

Naoki Hirasawa

Katsuji Kimura

Hirofumi Matsumoto

Kouzou Kage

Yutaka Sasaki

Takao Ono

Hiroshi Uesugi

Keizo Tomuro

Shigeyoshi Katoh

Yoko Morimoto

A rod antenna is contained to be slant in a housing case, such that a top of the rod antenna is positioned on the side of the housing case remote from a user head, and a bottom of the rod antenna is on the side of the housing case near the user head. The remote and near sides are opposite to each other. When the rod antenna is pulled up out of the housing case, the rod antenna top becomes more remote from the user head in accordance with the slantly contained mode.

Portable telephone set

A portable radio apparatus having a casing thereof keeps a matching state of an antenna thereof in the call waiting state and in the operating state of the apparatus. The casing is foldable and expandable and accommodates therein a transmitting and receiving circuit connected via a variable matching circuit to the antenna. The matching circuit is connected to a sensor disposed in the casing for sensing a folded state thereof. Depending on a result of the sensing operation of the sensor, the matching circuit changes the matching state.

Portable radio apparatus having variable impedance matching circuit

An antenna for a portable radio apparatus has a first antenna construction connected to the casing of the apparatus and a second antenna construction affixed to a base plate or earth plate which is incorporated in the casing. The first antenna construction has a movable joint which allows the first antenna construction to move between a first position where it is regarded as forming a part of the contour of the casing and a second position where it is protruded from the contour and regarded as being located in free space. The second antenna construction corrects the matching state of the first antenna construction such that adequate antenna radiation characteristics are set up in the first position. Optimal antenna characteristics are, therefore, achievable when the first antenna construction is in any one of the first and second positions.

Antenna system for portable radio apparatus

A mobile radio transceiver comprises a portable transceiver and a vehicular power booster. The portable transceiver generates a RF transmit signal and sets the power of the RF signal at one of multiple power levels. The power booster is coupled by a connecting cable to the transceiver to receive the RF signal, and includes a first power detector for detecting the power of the received signal. One of multiple reference voltages is identified as corresponding to the power detected by the first power detector. A gain-controlled power amplifier stage amplifies the RF signal from the transceiver for coupling to an antenna. The output power of the power amplifier is detected and a gain control driver responds to a difference between it and the identified voltage by controlling the power amplifier so that the difference reduces to a minimum. In a modification, the power amplifier stage is a class C amplifier and the booster additionally includes a preamplifier stage. A second gain control driver is responsive to a difference between an average output voltage of the preamplifier stage and a fixed value for controlling the preamplifier so that its output is maintained constant. The output of the second gain control driver is used to identify one of the reference voltages supplied to the first gain control driver as corresponding to the power setting of the transceiver.

Vehicular power booster circuitry for multi-level portable transceiver

In a plug and a receptacle of a microstrip line connector, the plug has a rectangular parallelpipedic insulating support block, a signal contact projecting upward from the center of the insulating support block and a pair of L-angle brackets projecting out upward from both ends of the insulating support block, the pair of brackets being connected to opposite ends of a coupling plate portion provided along the side wall surface of the insulating support block. The coupling plate portion has at the center of its lower marginal edge a recess formed astride a signal conductor of a microstrip line provided on a printed circuit board. The receptacle is made up of a rectangular parallelpipedic insulating housing having three contact housing rooms defined by two partition walls, a signal socket contact housed in the central contact housing room, a U-shaped ground socket contact having two contact portions housed in the side contact housing rooms, and a shield cover mounted on the insulating housing in a manner to cover almost all over its back and hold its top and bottom panel portions. The insulating housing has a contact introducing hole in its front panel portion centrally thereof and communicating with the central contact housing room, for receiving the signal contact of the mating plug. The insulating housing has slots in its side panel portions in the front-to-back direction and communicating with the side contact housing rooms, for receiving opposed edges of the pair of L-angle brackets.

Plug and receptacle of a microstrip line connector

An apparatus having a rechargeable battery and a battery voltage detector which detects the output voltage of the battery to produce a detection signal when the output voltage falls below a predetermined threshold level. A controller stores a battery capacity value and accumulates the discharge of the battery to produce an accumulated capacity value. The controller also calculates a difference between the stored capacity value and the accumulated capacity value. Using the difference, a display displays the remaining charge value of the battery thereon. If the difference exceeds a predetermined value at a time the controller receives the detection signal, the controller changes the stored capacity value to a new capacity value. Alternatively, the controller may change a rate of accumulating the battery discharge. The apparatus may have a current detector for detecting a current flowing through the battery. The controller may accumulate the battery discharge based on the detected current.

Apparatus for displaying the remaining charge of rechargeable battery

A plug connector used to connect a microstrip line and another microstrip line. The body of the plug connector, which is made of an insulating material of an oblong shape, has a signal contact housing hole and a ground contact housing hole. These holes are in parallel and opposed to each other. A signal female contact made of a metal plate is housed in the signal contact hole and a ground female contact made of a metal plate is contained in the ground contact housing hole. The ground female contact has a ground plate of a width wider than the width of the signal female contact. The ground female contact and the signal female contact constitute substantially a microstrip line.

Plug connector for microstrip line

A portable radio communication apparatus includes a first antenna that can extend away from, or be retracted towards, an apparatus housing. The apparatus includes a second, usually flat antenna mounted within or around the outer periphery of the housing. When the first antenna is extended away from the housing, it is connected via a switch to a node, in turn, connected via respective filters to both a transmitter and a diversity receiver. At this time, the second antenna is connected to the diversity receiver via a respective filter. When the first antenna is sufficiently retracted towards the housing, a switch, mechanically coupled to the first antenna, disconnects the first antenna from the node, connects the second antenna to such node, and disconnects the second antenna from the diversity receiver.

Portable radio communication apparatus having diversity reception

In a relay circuit, a stationary contact of a relay is coupled to a DC voltage source and a moving contact of the relay is coupled to a load circuit. The moving contact is switched to the stationary contact in response to a rapidly rising edge of a DC voltage applied to the relay. A voltage sensor is connected to the moving contact for detecting a voltage which appears thereat. For operating the relay, a switch is closed to apply a voltage from the DC voltage source to a pulse generator. The pulse generator generates a rectangular pulse and applies it to the relay to cause it to switch the moving contact to the stationary contact. If a voltage is not detected by the voltage sensor at the moving contact after energization of the relay, the pulse generator reapplies a rectangular pulse to the relay until a voltage appears at the moving contact, whereupon the pulse generator applies a constant voltage to the relay.

Relay circuit having a pulse generator for closing contacts

A temperature stabilized RF detector has a first diode connected between an input terminal for receiving an RF signal and an output terminal for outputting the detection signal of the RF signal, and a second diode connected between the input terminal and a constant voltage source through a buffer circuit. Connecting directions of the first and second diodes are opposite to each other in a circuit for connecting the output terminal and the constant voltage source.

Temperature stabilized RF detector

A booster and charger unit for a hand-held portable (HHP) telephone capable of preventing a casing of the unit from being heated to an excessive temperature. The casing has thereinside a charging device for charging a battery, which is installed in the telephone, and a temperature sensor responsive to the temperature of the casing. When the temperature of the casing sensed by the sensor rises to a predetermined level, charging by the charging device is interrupted or the charging current thereof is reduced.

Booster and charger unit used for hand-held portable telephone and

A temperature stabilized RF detector uses a series circuit including a detecting diode coupled in series with a similarly poled stabilizing diode so that a single current flows in a single direction through both diodes. The temperature related effects of the two diodes are mutually balancing so that temperature variations in the detecting diode do not adversely affect the detection of an RF signal.

A noise detection circuit for a digital radio receiver comprises a sampling circuit for sampling a digital baseband signal having a noise component when an eye opening of the baseband signal is largest. A waveform generator is connected to the output of the sampling circuit for generating a waveform which is a replica of the baseband signal and free from the noise component. The waveform generator comprises a threshold comparator having decision thresholds and a waveform recovery circuit which includes a resistor, a plurality of storage capacitors of equal values and a switch responsive to the output of the threshold comparator for selectively coupling the output of the sampling circuit through the resistor to the storage capacitors. A substractor is connected to the outputs of the sampling circuit and the waveform generator for generating a signal representative of the noise component of the baseband signal. The output of the subtractor circuit can be used for various purposes including noise measurement, squelch action and automatic local oscillator frequency control.

Noise detection by sampling digital baseband signal at eye openings

Method for optical resolution of DL-cysteine by (1) reacting DL-cysteine with formaldehyde to prepare DL-thiazolidine-4-carboxylic acid (DL-TCA), (2) forming diastereomer salts of D-TCA and of L-TCA by reacting DL-TCA with an optically active 1-(1-naphthyl)ethylamine, (3) separating said diastereomer salts by difference of the solubilities thereof in a solvent, (4) recovering D-TCA from said diastereomer salt of D-TCA and finally obtain D-cysteine, and recovering L-TCA from said diastereomer salt of L-TCA and finally obtain L-cysteine. Method for optical resolution of (R,S)-1-(1-naphthyl)ethylamine (R,S)-NEA by (1) reacting an optically active cysteine with formaldehyde to prepare an optically active thiazolidine-4-carboxylic acid, (2) forming diastereomer salts of (R)-NEA and of (S)-NEA by reacting (R,S)-NEA with optically active thiazolidine-4-carboxylic acid, (3) separating said diastereomer salts of (R)-NEA and of (S)-NEA by difference of the solubilities thereof in a solvent, (4) recovering (R)-NEA from said diastereomer salt of (R)-NEA, and recovering (S)-NEA from said diastereomer salt of (S)-NEA.

Method for optical resolution of DL-cysteine and (R,S)-1-(1-naphthyl)

A battery-powered radio communication apparatus is disclosed which comprises a power amplifier and a power detector for detecting the output power of the power amplifier. A supply voltage detector compares a standard voltage with the output voltage of a battery supplying power to the power amplifier. A gain control circuit controls the gain of the power amplifier in response to the output of the power amplifier and to the output of the supply voltage detector so as to prolong, by a certain time, the communicable state of the apparatus prior to battery depletion.

Growing community of inventors

Tokyo, Japan

Yoshiharu Tamura