Transmitter and semiconductor integrated circuit for communication

A transmitter comprising:

• a base band circuit formed into a semiconductor integrated 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 phase control loop is shared as a phase control loop for use in said first modulation mode and a phase control loop for use in said second modulation mode.