Abstract: A DC offset cancellation circuit used for compensating a carrier leak at an output signal of a modulator has a sign extraction unit for extracting sign of an information signal which is applied to the modulator, an envelope detecting unit for performing envelope detection on the output signal of the modulator to output the resulting envelope, a slope detecting unit for performing polarity detection on the slope of the envelope; and a signal processing unit for generating a DC offset cancellation signal for compensating the carrier leak based on the result of the sign extraction and the result of the polarity detection. The signal processing unit preferably calculates the DC offset cancellation signal by multiplying the sign of the information signal by the polarity of the slope of the envelope and accumulating the result of multiplication.

Abstract: An error calculation circuit used for compensating a carrier leak at an output signal of a mixer has a sign extraction unit for extracting the sign of a baseband signal which is applied to the mixer, an envelope detecting unit for performing envelope detection on the output signal of the mixer, and a signal processing unit for generating an error compensation signal to compensate the carrier leak based on the result of the sign extraction and envelope detection. The signal processing unit preferably calculates the compensation signal by using multiplication of the sign of the baseband signal by an amplitude of the envelope.

Abstract: A DC offset cancellation circuit used for compensating a carrier leak at an output signal of a modulator has a sign extraction unit for extracting sign of an information signal which is applied to the modulator, an envelope detecting unit for performing envelope detection on the output signal of the modulator to output the resulting envelope, a slope detecting unit for performing polarity detection on the slope of the envelope; and a signal processing unit for generating a DC offset cancellation signal for compensating the carrier leak based on the result of the sign extraction and the result of the polarity detection. The signal processing unit preferably calculates the DC offset cancellation signal by multiplying the sign of the information signal by the polarity of the slope of the envelope and accumulating the result of multiplication.

Abstract: An error calculation circuit used for compensating a carrier leak at an output signal of a mixer has a sign extraction unit for extracting the sign of a baseband signal which is applied to the mixer, an envelope detecting unit for performing envelope detection on the output signal of the mixer, and a signal processing unit for generating an error compensation signal to compensate the carrier leak based on the result of the sign extraction and envelope detection. The signal processing unit preferably calculates the compensation signal by using multiplication of the sign of the baseband signal by an amplitude of the envelope.