ASK MODULATION DEVICE

PROBLEM TO BE SOLVED: To provide the ASK modulated high frequency signals of a high frequency at a low cost. SOLUTION: First high frequency signals f1 are generated and branched into two by a crystal oscillator 101, a PLL 102, a VCO 103 and a frequency divider 104, one is inputted to a multiplier 105 and second high frequency signals f2 are generated. The other branched one is inputted to an ASK modulator 106 and ASK modulation is performed by modulation signals from which higher harmonic components are removed by an LPF 107. Respective outputs are inputted to an up converter 108 (or down converter) and the ASK modulated third high frequency signals f3 of the high frequency are taken out. By passing the output of the multiplier 105 or the output of the up converter 108 (or down converter) through a band-pass filter and removing unrequired signals, the ASK modulated high frequency signals of higher quality are obtained.