摘要 |
<p>A signal receiving arrangement comprising first and second groups (14, 16) of frequency down-converting stages (18 to 24 and 26 to 34), each stage including a mixer (40) and a local oscillator (42) for frequency down-converting a signal applied to the stages (18 to 24 and 26 to 34), the local oscillator frequencies of successive stages (18 to 24 and 26 to 34) being progressively higher with the frequency differences between correspondingly numbered stages in each group forming an arithmetic progression, wherein the frequency down-converted outputs of the stages of each group are combined and the pair of residue frequencies formed by mixing down the input signal are used to determine on the basis of the Chinese remainder theorem which stage in each group was operative on the input signal and thereby ascertain the actual frequency of the input signal.</p> |