| 摘要 |
PROBLEM TO BE SOLVED: To constitute an amplitude modulator enabling miniaturization/cost reduction and an amplitude modulation with an excellent linearity. SOLUTION: A low-pass filter LPF as a variable frequency filter being composed of inductors L1, L2 and L3, a capacitor C2 and a variable capacity diode VD and having low-pass filter characteristics is constituted, and a modulation signal is imparted from a modulation-signal input terminal 80 as a control signal for the low-pass filter LPF. An amplitude is modulated by using the attenuation characteristics of the variable frequency filter when carrier waves input from a carrier-wave input terminal 60 are output from a carrier-wave output terminal 70. COPYRIGHT: (C)2007,JPO&INPIT
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