| 摘要 |
PURPOSE:To obtain a desired amplitude modulation signal by smoothly changing an output signal, by adding an analogue phase modulation circuit for interpolating the min. bit phase shift interval. CONSTITUTION:The input signal of an analogue phase modulation circuit I is distributed to outputs A, B in a predetermined ratio by a power distributor 31 and the output A is applied to a high frequency bridge 3 while the output B is delayed by 90 deg. in a phase by a line 32 to be applied to an amplitude modulator 33 and supplied to the bridge 34 as a signal 52 modulated in amplitude by the control signal T of a terminal 51 and both signals are synthesized vectorially. The signal of an output terminal a1 is delayed by 90 deg. by a line 14, and the delayed signal and the signal of an output terminal a3 are respectively supplied to digital phase shifters 35, 36. The phases of the output signals of both phase shifters continuously change to be inputted to a high frequency bridge 18 and a signal vectorially synthesized is obtained between the output terminals b2, b4 thereof.
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