Robert J Hargis

US Patent:

40328589, Jun 28, 1977

Filed:

Jun 3, 1976

Appl. No.:

5/692698

Inventors:

Robert Norman Hargis - Wheaton IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03B 304

US Classification:

331 9

Abstract:

A controllable oscillator is maintained at a center frequency f. sub. o by the inventive system. The oscillator signal is directly coupled to one input of a diode detector via a first path, and is alternately coupled, at a clock signal rate, to the second detector input via second or third paths. The second path has a selected transfer characteristic such that when it passes the oscillator signal the diode detector output is at a null. The third path includes a resonator whereby the oscillator signal passed therethrough results in a null at the detector output only when the oscillator is tuned to f. sub. o. The diode detector output is then phase detected with the clock signal thus producing an output correction signal which, when integrated, is fed back to the oscillator for precise control thereof. Since the system correction is dependent solely on an AC signal, errors due to the DC characteristics of the components, e. g. the detector diodes, may be eliminated.

US Patent:

41562046, May 22, 1979

Filed:

Jun 3, 1976

Appl. No.:

5/692697

Inventors:

Robert N. Hargis - Wheaton IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H03B 304

US Classification:

331 12

Abstract:

The inventive synchronization circuit accepts a reference input signal and produces a signal which is in both phase and frequency lock therewith. The reference signal is quadrature detected via a voltage controlled oscillator signal, a quadrature phase shifter and a pair of mixers. A frequency error signal is generated by processing the mixer outputs through a phase detector and integrator. A phase error signal is produced by extracting and combining the DC components of the signals at the mixer outputs. The frequency and phase error signals are summed to produce a control signal which is fed back to the voltage controlled oscillator, thus causing the oscillator signal to tend to lock in frequency and phase with the input reference signal.