Pulse or digital communications – Receivers
Reexamination Certificate
2005-11-22
2005-11-22
Ghayour, Mohammed (Department: 2631)
Pulse or digital communications
Receivers
Reexamination Certificate
active
06968017
ABSTRACT:
One aspect of the present invention is a frequency conversion circuit having a pair of local oscillators. The local oscillators are frequency synthesizers based on an external frequency reference. The frequency conversion circuit is configured to perform a frequency conversion to an input signal equal to a frequency difference of signals from the pair of local oscillators; to generate an oscillator frequency difference signal; to generate an error signal using the oscillator frequency difference signal and an internal reference signal derived from the external frequency reference; and to adjust a phase of one of the pair of oscillators using the error signal. The above-described frequency conversion circuit embodiment essentially eliminates divider phase noise such as that generated by traditional prescalers. In addition, the use of two local oscillators provides a frequency conversion circuit capable of wide-range frequency conversion and high resolution. This frequency conversion circuit embodiment is suitable for receivers as well as transmitters, and is particularly suitable for digital television systems.
REFERENCES:
patent: 4152669 (1979-05-01), Igarashi
patent: 4259644 (1981-03-01), Iimura
patent: 4491976 (1985-01-01), Saitoh et al.
patent: 4726072 (1988-02-01), Yamashita et al.
patent: 5282222 (1994-01-01), Fattouche et al.
patent: 5388125 (1995-02-01), Toda et al.
patent: 5574998 (1996-11-01), Andoh
patent: 5648985 (1997-07-01), Bjerede et al.
patent: 5726973 (1998-03-01), Isaksson
patent: 5949796 (1999-09-01), Kumar
patent: 6052419 (2000-04-01), Hioki
patent: 6160858 (2000-12-01), Hindman et al.
patent: 6320915 (2001-11-01), Stott et al.
European Search Report for corresponding European Patent Application No. EP 01 30 5689, Nov. 5, 2003; 2 pp.
Armstrong Teasdale LLP
Flanagan Krista
Ghayour Mohammed
Unique Broadband Systems, Inc.
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