| 摘要 |
<p>A down-converter for processing frequency signals, preferably received, particularly digital, television signals, comprising two, preferably identical mixer stages (10a, 10b) for down-converting the signal, a local oscillator (12) controlling the mixer stages by a 90° phase shift, a complex filter (14) which couples the output signals of the mixer stages (10a, 10b) by means of a complex filtering method in such a way that the signal components outside a predetermined useful band are substantially suppressed, an adjusting device (13) for adjusting the frequency of the local oscillator (12) and a subsequent low-pass filter.</p> |
