Kabushiki Kaisha Toshiba

Tadahiko Maeda

Syuichi Sekine

Hiroyuki Kayano

Hiroshi Yoshida

Shoji Otaka

Hiroshi Tsurumi

Shuichi Obayashi

Syuuichi Sekine

Yasuo Suzuki

Yoshiaki Terashima

Hisashi Yoshino

Minoru Sakurai

Satoshi Yasuda

Yoshiaki Tsukumo

Koji Iino

Syuichi Obayashi

In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured-radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process. In the radio apparatus, a transmission power detecting portion is structured as an IC chip. The transmission power detecting portion detects the transmission power corresponding to leakage currents in the power supply of the IC chip and the ground. Thus, when the power is detected, a power loss is suppressed. Consequently, the power consumption of the radio apparatus can be decreased.

Radio apparatus

In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process. In the radio apparatus, a transmission power detecting portion is structured as an IC chip. The transmission power detecting portion detects the transmission power corresponding to leakage currents in the power supply of the IC chip and the ground. Thus, when the power is detected, a power loss is suppressed. Consequently, the power consumption of the radio apparatus can be decreased.

A first electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication, a dielectric layer whose permittivity is changed by application of electric field, and a second electrically conductive layer whose thickness is equal to or smaller than the skin depth of the radio wave used for communication are sequentially stacked near a resonance element which is formed on the front surface of a dielectric substrate having a ground layer formed on the rear surface thereof. The effective permittivity of the dielectric layer is changed in a wide range by changing a voltage applied between the first and second electrically conductive layers to change the electric field applied to the dielectric layer. As a result, the impedance of the resonance element is changed, and when a plurality of resonance elements are arranged closely to each other to construct a filter, the coupling degree between the resonance elements is changed. Therefore, characteristics such as the resonance frequency of the resonator and the pass-band frequency of the filter are controlled by controlling a voltage to be applied.

Tunable resonance device controlled by separate permittivity adjusting

A portable radio communication device capable of eliminating the deterioration of the radiation efficiency due to the occurrence of the dual resonance on the antenna, without reducing the bandwidth. A radio communication device, comprises: a device body made of a conductor body, containing at least one of a radio transmitter and a radio receiver; and an antenna, mounted on the device body, formed by first and second strip-like conductor elements which are connected together at a feeding point connected with said at least one of the radio transmitter and the radio receiver, the first and second strip-like conductor elements having an identical electrical length with each other.

Portable radio communication device with wide bandwidth and improved

A portable radio and telephone equipment for transmitting and receiving an electric wave. The portable radio and telephone equipment includes: an antenna for transmitting and receiving an electromagnetic wave; a housing connected to the antenna, having a notch therein; and an internal circuit, connected to the antenna by way of the housing, for generating and receiving the electromagnetic wave. The portable radio and telephone equipment includes: an antenna for transmitting and receiving an electromagnetic wave; an upper portion of a housing connected to the antenna; and a lower portion of a housing connected to the upper portion of the housing via a conductor wire, so that the housing is divided into two portions in order to vary distribution pattern of the electromagnetic wave.

Portable radio and telephones having notches therein

A two-stage power amplifier device for use in a digital hand-held radiophone includes a first and a second amplifier circuit. The first amplifier is an exciter-stage amplifier for receiving a high-frequency input signal corresponding to a modulation signal to generate an amplified signal at its output. The second amplifier is a final-stage amplifier connected to either the input signal or the output of the exciter amplifier. A detector circuit is connected to the exciter amplifier, for monitoring variations in a bias current to be fed to the exciter amplifier, and for generating a detection signal indicative of the current variation thus detected. A linearizer circuit is connected to the detector and the final-stage amplifier. The linearizer is responsive to the detection signal, for forcing a bias voltage given to the final-stage amplifier to vary in potential while causing the bias voltage to remain in a univocally determinable relationship with a waveform of said input signal, to thereby increase the linearity of the final-stage amplifier.

High-frequency power amplifier device with drain-control linearizer

The present invention relates to an apparatus for measuring antenna radiation efficiency, wherein a random field measurement method can be adopted. In this apparatus, a to-be-measured antenna and a standard antenna are situated in a frame. In the frame, a plurality of rods, which are horizontally movable and extend vertically, are supported. A plurality of radio wave scatterers whose intervals and curvatures can be determined at random are held to the rods. In the frame, a random field is created by the radio wave scatterers.

Method and apparatus for measuring antenna radiation efficiency

A radiation field characteristic measuring apparatus comprises a rotating device for rotating a tested object through the total solid angle thereof, and a device for receiving electromagnetic waves radiated from the object, thereby measuring electromagnetic field characteristics of the object with respect to the total solid angle. According to the present invention, almost all the components of the rotating device are formed of a nonmetallic material, and spaces to allow the passage of the electromagnetic waves are formed in the components of the rotating device. Thus, reflection and scattering of the electromagnetic waves are suppressed, so that the radiation field characteristics of the tested object, with respect to the total solid angle thereof, can be obtained with high accuracy. Also, the effective radiated power is measured with use of the arrival probability density function of radio waves as a weighting function. By doing this, the evaluation index of an antenna best suited for the actual radio conditions can be obtained.

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Menlo Park, CA, United States of America

Tadahiko Maeda