| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-frequency attenuator that can use a control signal for varying amplitude at up to several tens of MHz and has a small amount of phase shift. SOLUTION: The high-frequency signal of an input signal from an input terminal 1 is distributed to a distributor 2, a phase shifter 5 for performing the phase control of a 0°output signal, and a phase shifter 6 for performing phase control of a 90°output signal of the distributor each, and an output signal in which a phase is controlled by the control signal (Vcont) from the phase shifters 5, 6 is synthesized by a synthesizer 4 for outputting. In the phase shifter 5, phase is shifted by the control signal supplied via a non-inverted amplification circuit 7. In the phase shifter 6, phase shift is controlled by the control signal inverted via a differential amplification circuit 8. There is a delay circuit composed of a time constant adjustment resistor 21 for compensating the delay difference between the control signal to the phase shifter 5 and that to the phase shifter 6, and a time constant adjustment capacitor 22. COPYRIGHT: (C)2005,JPO&NCIPI
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