Patent ID: 7358829

Claim:
A transmission apparatus synthesizing an amplitude component and a phase component using polar modulation and generating and transmitting a vector modulation wave, the transmission apparatus comprising: a polar coordinate component modulation signal generating section that forms an amplitude component modulation signal and a phase component modulation signal based on an input signal; a delay time adjusting section that changes a delay time difference between the amplitude component modulation signal and the phase component modulation signal; a phase modulating section that forms a phase modulation wave where a carrier wave is phase-modulated by the phase component modulation signal; an amplifying section that, receiving as input the phase modulation wave at a signal input terminal of the transmission apparatus, with the amplitude component modulation signal applied to a power supply voltage terminal of the transmission apparatus, forms a vector modulation wave where the phase modulation wave is amplitude-modulated by the amplitude component modulation signal; a synchronous demodulating section that synchronously demodulates the vector modulation wave and forms a synchronous demodulation signal; a band filtering section that extracts and outputs a signal of a specific frequency component contained in the synchronous demodulation signal; and a controlling section that controls the delay time adjusting section in such a manner that the level of the output signal of the band filtering section becomes small, wherein: the polar coordinate component modulation signal generating section comprises: (i) an in-phase/quadrature component modulation signal generating section that forms an in-phase component modulation signal and a quadrature component modulation signal; and (ii) a coordinate converting section that forms the amplitude component modulation signal and phase component modulation signal based on the in-phase component modulation signal and the quadrature component modulation signal; the in-phase/quadrature component modulation signal generating section forms a first sine wave signal having a first frequency f 1 and a first phase angle p 1 as the in-phase component modulation signal and a second sine wave signal having a second frequency f 2 that is the same as the first frequency of f 1 and a second phase angle p 2 where the difference with the first phase angle p 1 is not an integer multiple of ninety degrees, as the quadrature component modulation signal; the band filtering section extracts a signal of a frequency component that is the second frequency f 2 expressed by a value that is n times the first frequency f 1 ; and the value of n is an odd number of three or more.