Title:
FREQUENCY ACQUISITION AND LOCKING DETECTION CIRCUIT FOR PHASE LOCK LOOP
Document Type and Number:
WIPO Patent Application WO2003043194
Kind Code:
A3
Abstract:
A method and apparatus for providing frequency acquisition and locking detection for a phase lock loop is disclosed. The phase lock loop locks a receiver local oscillator to the frequency and phase of an RF carrier to allow data to be recovered from the RF carrier in the receiver. An analog mixer in the phase lock loop compares the frequency and phase of a receive LO output by a voltage controlled oscillator in the phase lock loop and the received RF carrier. A locking indicator dependent on the result of the comparison indicates whether the phase lock loop is locked. The locking indicator is coupled to a comparator. The comparator generates a pulse to close a switch in order to inject a periodic sweeping signal generated by a free running multi vibrator into the phase lock loop to push the receiver LO into the locking range.
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| JP3172484 | TELEVISION RECEIVER |
Inventors:
WU MIAOCHEN
ZHANG XIANGDONG
ALEXANIAN ANGELOS
YE WEI
ZHANG XIANGDONG
ALEXANIAN ANGELOS
YE WEI
Application Number:
PCT/US2002/035710
Publication Date:
February 19, 2004
Filing Date:
November 06, 2002
Export Citation:
Assignee:
NARAD NETWORKS INC (US)
International Classes:
H03J7/20; H03L7/095; H03L7/12; H04L12/28; H04L27/38; H04L27/00; (IPC1-7): H03L7/12; H03J7/20; H03L7/095
Foreign References:
| US4713630A | 1987-12-15 | |||
| US4423390A | 1983-12-27 | |||
| EP0297774A2 | 1989-01-04 | |||
| US4316154A | 1982-02-16 | |||
| US6295327B1 | 2001-09-25 |
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