RF SIGNAL GENERATING CIRCUIT, AND TRANSMITTER

摘要

An RF signal generating circuit that generates, from a digital signal, an RF pulse signal to be radio-transmitted. It includes a polar converter generating an amplitude signal and a phase signal from the digital signal; a signal decomposer receiving the amplitude signal as an input signal, and generates two signals, a pulse width control signal and a residual signal; a delta sigma modulator subjecting the residual signal to delta-sigma modulation; a pulse width modulator subjecting the phase signal to pulse modulation in accordance with the pulse width control signal, and outputting a pulse phase signal; and a mixer that mixes a signal output from the delta sigma modulator and the pulse phase signal to output the RF pulse signal. The signal decomposer generates the pulse width control and residual signals if a product of a fundamental wave component of the pulse phase and residual signals equals the amplitude signal.

主权项

1. An RF signal generating circuit that generates, from a digital signal, an RF pulse signal to be radio-transmitted, the circuit comprising:
a polar converter that generates an amplitude signal and a phase signal from the digital signal; a signal decomposer that receives, as an input signal, the amplitude signal output from the polar converter, and generates two signal which are a pulse width control signal and a residual signal; a delta sigma modulator that subjects the residual signal to delta-sigma modulation; a pulse width modulator that subjects the phase signal output from the polar converter to pulse modulation in accordance with the pulse width control signal, and outputs a pulse phase signal; and a mixer that mixes a signal output from the delta sigma modulator and the pulse phase signal together to output the RF pulse signal, wherein the signal decomposer generates the pulse width control signal and the residual signal under a condition that a product of a fundamental wave component of the pulse phase signal and the residual signal equals the amplitude signal.