| 摘要 |
<p>A method for removing signal residues outside the working frequency band of radio signal transceivers using a quadrature signal modulator-demodulator consisting of two quadrature channels (3, 4), wherein the low-frequency transmit signal applied to the input of the two channels is mixed by a carrier signal from a local oscillator (5). The method comprises shifting the spectrum of the low-frequency transmit signal applied to the quadrature channels, and filtering out (10) the unwanted vestigial band of the spectrum of the output from the two quadrature channels, using a filter with a pass-band set to the working frequency band of the transmitter. The method is useful in SSB transceivers.</p> |
