| 摘要 |
The arrangement comprises a frequency doubler (10), a circuit (11) for generating a clock signal component from the frequency-doubled signal, a clock filter (16) for selecting the generated clock signal component and a pulse shaper (17) for producing a clock pulse signal.
<??>The arrangement produces a reliable clock signal within a very short time after the start of the signal reception, because the frequency doubler comprises a hard limiter (20), a first bandpass filter (21) connected thereto and having Q </= 10, a balanced modulator (22) connected to the limiter and to the first bandpass filter and a second bandpass filter (23) having Q </= 10 tuned to twice the carrier frequency 2fc; and because the generating circuit comprises a frequency converter (26) for converting the frequency-doubled signal to a frequency band around a carrier frequency f of the order of twice the clock frequency 2/T, a bandstop filter (28) tuned to frequency fo and having Q </= 10 and a squaring circuit (29) connected to the band stop filter. The arrangement is attractive for use in receivers for radio cation systems which require a very fast acquisition of the correct clock phase. |
