ASK MODULATOR, AND COMMUNICATION DEVICE USING THE SAME

PROBLEM TO BE SOLVED: To provide an ASK (amplitude shift keying) modulator capable of preventing the lowering of a modulation on/off ratio which occurs in a high frequency, and to provide a communication device using the ASK modulator. SOLUTION: An output part of a carrier compensation circuit 2 that simulates a carrier leakage path of an ASK modulating part 1 and an output part of the ASK modulating part 1 are connected to an adder circuit 3, and an output part of the adder circuit 3 is connected to an output terminal T2. A carrier LO0 being an antiphase to a carrier LO1 is inputted to the carrier compensation circuit 2 to output a carrier compensation signal LCO from the compensation circuit 2, negating a carrier signal MODO that leaks from the ASK modulating part 2 to which the carrier LO1 is inputted at the time of OFF of modulation in the adder circuit 3. COPYRIGHT: (C)2004,JPO&NCIPI