Patent Number: 7,085,544

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

Abstract: 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.

Inventors: Takano; Ryoichi (Takasaki, JP), Hikasa; Kazuhiko (Hamura, JP), Kimura; Yasuyuki (Maebashi, JP), Hagisawa; Hiroshi (Tamamura, JP), Wurm; Patrick (Comberton, GB), Henshaw; Robert Astle (Sudbury, GB), Freeborough; David (Balsham, GB)

Assignee: Renesas Technology Corp.

International Classification: H04B 1/02 (20060101)

Expiration Date: 8/01/02018