Title:
DIGITAL SYNCHRONIZATION OF BROADCAST FREQUENCY
Document Type and Number:
WIPO Patent Application WO1998037705
Kind Code:
A3
Abstract:
A dynamic, self adjusting synchronization system for real time control of the frequency and bandwidth of a modulated signal includes a voltage controlled oscillator for generating a carrier signal to be modulated having a predetermined frequency and bandwidth. There is an adjustment device having a center frequency adjustment circuit for providing a voltage level to the voltage controlled oscillator. A modulation generator generates a modulation signal for modulating the carrier signal to produce a modulated carrier signal and a co-generated measurement signal synchronized with the modulation signal. There is a device for selectively inhibiting the modulation signal. A measurement device includes a counter device to selectively count the pulses of the modulated carrier signal for a first predetermined period of time and counting the pulses of the carrier signal for a second predetermined period of time while the modulation signal is inhibited and a measurement circuit, responsive to the co-generated measurement signal, to synchronously define the first predetermined period of time during which the modulated carrier pulses are counted and is responsive to a timing signal to define the second predetermined period of time during which the modulation signal is inhibited for counting the carrier pulses. The adjustment device is responsive to the measurement device, for varying the voltage applied to the voltage controlled oscillator to maintain the predetermined frequency of the carrier signal, and is responsive to the measurement device for varying the voltage applied to the voltage controlled oscillator to maintain the predetermined bandwidth of the modulated carrier signal.
Inventors:
LYONS CHRISTOPHER T
TASKIN ISMAIL
TASKIN ISMAIL
Application Number:
PCT/US1998/002970
Publication Date:
October 29, 1998
Filing Date:
February 10, 1998
Export Citation:
Assignee:
HITTITE MICROWAVE CORP (US)
International Classes:
B60R21/00; G01S13/931; B60R21/16; G01S7/28; G01S7/40; H03L7/00; G01S7/35; (IPC1-7): H04Q/
Foreign References:
| US4816781A | 1989-03-28 | |||
| US4573017A | 1986-02-25 | |||
| US5703539A | 1997-12-30 |
Other References:
See also references of EP 0960533A4
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