| 摘要 |
PROBLEM TO BE SOLVED: To provide an endless phase shifter with a small passing loss capable of accurate phase shift amount control and being configured at a low cost. SOLUTION: A 90-degree hybrid circuit 11 distributes an input signal into two signals having a phase difference of 90-degrees and gives them to balanced mixers 12a, 12b. The balanced mixers 12a, 12b control the amplitude and polarity of output signals on the basis of a phase control voltage, composite the output signals and provide an output. A control circuit 15 respectively outputs DC voltages of cosθand sinθ, whereinθis a phase control signal, to offset circuits 21, 22 as control voltages. The offset circuits 21, 22 add offset signalsα,βto the cosθand sinθand give the result to balanced mixers 12a, 12b as phase control voltages X, Y so as to correct an offset of phase angle information attendant on the nonlinear characteristic, to control the amplitude of the phase control voltage, and to supplement the attenuation in the signal in the endless phase shifter thereby reducing the passing loss. COPYRIGHT: (C)2003,JPO
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