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

A transmitter comprising:

• a semiconductor integrated circuit having a base band circuit for generating I and Q signals in accordance with transmitting data;
• a transmitting oscillator for generating a carrier signal;
• a power amplification circuit for amplifying said carrier signal outputted from said transmitting oscillator;
• transmitting output power level detection means for detecting a level of a signal outputted from said power amplification circuit;
• and
• a semiconductor integrated circuit for modulation including
• an orthogonal modulator for modulating said I and Q signals onto said carrier signal so as to form an oscillating signal of a predetermined frequency,
• a phase control loop for controlling a phase of said carrier signal outputted from said transmitting oscillator,
• an amplitude control loop for controlling an amplitude of a transmitting output signal outputted from said power amplification circuit,
• a first variable gain amplification circuit provided on a feedback path between said transmitting output power level detection means and an amplitude detection circuit, and
• a second variable gain amplification circuit provided on a forward path between said amplitude detection circuit and said power amplification circuit;
• wherein said transmitter has a first modulation mode and a second modulation mode, and
• wherein said phase control loop is shared by said first modulation mode and said second modulation mode.

A transmitter for generating a modulated carrier signal, comprising:

• a first operating mode which modulates a phase component and an amplitude component of a carrier signal, and a second operating mode which modulates a phase component, but not an amplitude component, of said carrier signal;
• a first control loop for controlling amplitude and a second control loop for controlling phase in said first operating mode;
• wherein said first control loop is used for the acquisition of a phase lock in said first operating mode at the start-up time of output of said transmitter, and
• wherein said second control loop is used to control the phase of the modulated carrier signal in said second operating mode, and in said first operating mode before the start-up time of output of said transmitter.