Kabushiki Kaisha Toshiba

Mikio Hayashihara

Hiroshi Tanimoto

Hiroshi Tsurumi

Takashi Amano

Norimichi Chiba

Satoshi Arai

Manabu Ishibe

A gain control circuit has a transmission power amplifier that amplifies a transmission signal to a predetermined level. An adjacent channel leak power ratio monitor finds a ratio of a distortion element corresponding to an adjacent channel leak power to a main element from an output signal supplied from the transmission power amplifier, and outputs the found ratio as an ACPR monitor value. A power supply control section variously controls power supply to the transmission power amplifier with use of the ACPR monitor value supplied from the adjacent channel leak power ratio monitor. A transmission signal level variable section controls a gain of a transmission signal path on the basis of a transmission level monitor value supplied from the adjacent channel leak power ratio monitor, thereby varying a level of the transmission signal.

Radio communication terminal and gain control circuit for the same

A squaring circuit squares a radio transmission signal. A band-pass filter extracts a spectrum component corresponding to a desired channel, from that low-frequency component of the output of the squaring circuit, which occurs with a center thereof being present near a DC (Direct Current). A level measuring circuit measures the level of the extracted spectrum component. On the other hand, another band-pass filter extracts, from the output of the squaring circuit, a spectrum component corresponding to spectrum spreading due to a distortion in a transmission circuit. Another level measuring circuit measures the level of this extracted spectrum component. A level radio measuring circuit measures a ratio between the level measured by the level measuring circuit and the level measured by the other level measuring circuit, and produces the measured result as a ratio of a leak power to an adjacent channel.

Leak power ratio detection circuit, mobile communication terminal, and control circuit for mobile communication terminal

For use in a radiocommunication system using a frequency band close to a frequency band of a different radiocommunication system, a radiocommunication device, or a mobile, is controlled so that a maximum of transmission power is set according to an up-link frequency in use. The closer the up-link frequency in use is to the frequency band of the different radiocommunication system, the lower the maximum of transmission power is set.

Systems and methods for controlling transmission power to reduce frequency interference

A low-noise amplifier having low-distortion characteristics (low distortion LNA), a low-noise amplifier of a low current consumption type(low current consumption LNA), and radio-frequency switches and for selectively switching either of them are provided in a receiving radio-frequency unit . On the basis of a mode changing control function of a CPU , an LNA switch control signal AS is generated so that the low-distortion LNA is selected during a period in which the operation of a radio transmitter-receiver is in a transmitting/receiving state, and that the low current consumption LNA is selected in a period of a standby state, and thus the switching of the radio-frequency switches and of a low-noise amplifier circuit section is controlled.

Radio transmitter-receiver, high-frequency radio receiver, and control unit

In a design of the printed circuit board design device, a signal wire name is affixed to each wiring of a circuit, thereby making it quite easy to go through confirmation works after the design works are thoroughly accomplished. The present invention aims at improving efficiency of works for affixing the signal wire name. For this purpose, the signal wire names are input for each desired area of the circuit. By taking full advantage of overlap of the area concerned, the signal wire names connected in serial form are affixed to one wiring. The candidates of the signal wire names to be affixed are tabulated as a list. After the signal wire names are affixed to each wiring of the circuit, the wiring can be retrieved and shown in visible display. In this case too, the candidates of the signal wire names to be retrieved can be tabulated as a list.

Printed circuit board design device

A phase detection system in which an original modulation signal is detected from a first complex baseband signal obtained through orthogonal demodulation of an FM signal and output, a second complex baseband signal having cosine and sine components of a phase change .DELTA..phi. of the first complex baseband signal in a predetermined time interval .tau. is rotated until a rotation angle .theta. becomes .DELTA..phi., and rotation angle data indicative of the rotation angle .iota. is detected and output.

Phase detecting method and phase detector and FM receiver using phase

An FSK signal receiving device is constituted by a first phase shifting circuit for applying a first phase shift to a first reception base band signal of first and second reception base band signals having orthogonal phases to generate a third base band signal, and generating a fourth base band signal having a phase orthogonal to the phase of the third base band signal, a second phase shifting circuit for applying the first phase shift to the second base band signal to generate a fifth reception base band signal, and a logical gate circuit for performing an exclusive OR operation on the third and fourth base band signals to obtain a first output signal, on the third and fifth base signals to obtain a second output signal, and on the first and second output signals to generate a detection signal.

Growing community of inventors

Hachioji, Japan

Mikio Hayashihara