| 摘要 |
PURPOSE:To reduce the equipment cost by providing an object value generating means, a variable oscillation control means, a variable amplitude control means and a phase feedback control means in the equipment to control the variable amplitude control means corresponding to an amplitude object level and an amplitude error. CONSTITUTION:An analog phase object signal outputted from an object generating circuit 41, an output of a 1st detector 48, an output of a 2nd detector 52 and an output of a down-convert mixer 50 are fed to a phase comparator 49. The comparator generates a phase error signal from the signals and gives the signal to a VCO 42 via a VCO control circuit 53. A voltage controlled attenuator 43 is provided between the VCO 42 and a power amplifier 45 to extract part of an output of the amplifier 45. Thus, the circuit 41 applies negative feedback control to an oscillated frequency of the VCO 42 and an attenuation factor of the attenuator 43 based on a phase object and an amplitude object corresponding to an instantaneous phase and amplitude generated by the polar coordinate conversion system. Since the negative feedback is applied to the phase and amplitude, a nonlinear and efficient amplifier such as a class C amplifier is adopted for the amplifier 45. |
