Ttpcom Limited

Renesas Technology Corp.

Hitachi, Ltd.

Ttp Com Limited

Tipcom Limited

David Freeborough

Patrick Wurm

Robert Astle Henshaw

Kazuhiko Hikasa

Ryoichi Takano

Yasuyuki Kimura

Hiroshi Hagisawa

Noriyuki Kurakami

Kazuhisa Okada

Kenji Toyota

In a polar loop based radio-communications apparatus having a phase control loop for controlling the phase of a carrier outputted from an oscillator for transmission, and an amplitude control loop for controlling the amplitude of a transmission output signal outputted from a power amplification circuit, the phase control loop is first started while maintaining the amplitude control loop in an off state at the outset of transmission, and the amplitude control loop is started after stabilizing the phase control loop.

Semiconductor integrated circuit for communication, radio-communication apparatus, and transmission starting method

A transmitter adopting a polar loop system including a phase control loop for controlling the phase of a carrier signal outputted from a transmitting oscillator and an amplitude control loop for controlling the amplitude of a transmitting output signal outputted from a power amplification circuit, and designed to be capable of performing transmission using a GMSK modulation mode and transmission using an 8-PSK modulation mode. In the transmitter, the phase control loop is shared as a phase control loop for use in the GMSK modulation mode and a phase control loop for use in the 8-PSK modulation mode. A component similar to any one of components constituting a loop filter is provided in parallel therewith so that the component can be connected or disconnected in accordance with the modulation mode, for example, by use of a switching element.

Transmitter and semiconductor integrated circuit for communication

Wireless communication apparatus having a phase control loop shared by first and second modulation modes and an amplitude control loop

Semiconductor integrated circuit for communication, radio-communications apparatus, and transmission starting method

A mobile communication system has a mobile phone in which a voltage is set corresponding to the characteristic variation of a PA even when a PA having characteristic variation is used. The mobile phone employs a polar loop method, which comprises an antenna () for transmission and reception of signal waves; an antenna switch () for switching the transmission mode and the reception mode; a BBLSI () having a function to control the transmission and reception; an RFIC () having a function for modulating and demodulating the transmitted and received signals; and a PA () for amplifying up to the target output power by means of the amplitude modulation at the time of the transmission.

Apparatus for mobile communication system which performs signal transmission by amplitude modulation and phase modulation

Transmitter having a phase control loop whose frequency bandwidth is varied in accordance with modulation modes

A polar-loop wireless communication apparatus includes, on a forward path between an amplitude detector and a power amplifier which constitute an amplitude control loop, a variable gain amplifier and a switch to change characteristics of a loop filter to output a frequency bandwidth of the amplitude control loop to an order less than an order for normal operation. The system is operated with the characteristics set to the lower order to measure outputs from the power amplifier to calibrate the output power of the power transmitter, and the register is operated with the characteristics set to the higher order to measure the open loop gain of the amplitude control. According to results of the calculation, data to correct gain characteristics of the variable gain amplifier with respect to an output control signal is stored in a nonvolatile memory of a baseband circuit.

Communication semiconductor integrated circuit, a wireless communication apparatus, and a loop gain calibration method

An antenna circuit for a mobile telecommunication device. The circuit comprises a power amplifier for amplifying, in use, a signal to be transmitted. An antenna transmits signals output from the power amplifier. Switching means introduces, dependent upon the gain setting of the power amplifier, an attenuator between the output of the power amplifier and the antenna.

Antenna circuitry

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Balsham, United Kingdom

David Freeborough