Apparatus and method for producing linear frequency sweep

Patent 4754277 Issued on June 28, 1988. Estimated Expiration Date:

September 2, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3344423

3621450

3699448

Wideband phase locked loop transmitter system
Patent #: 3958186
Issued on: 05/18/1976
Inventor: Jesse , et al.

Swept oscillator automatic linearizer
Patent #: 4038612
Issued on: 07/26/1977
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Inventor: Hofmann

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Patent #: 4245196
Issued on: 01/13/1981
Inventor: Peebles, Jr. , et al.

Method and apparatus for increasing the sweep rate of a linearly swept frequency oscillator
Patent #: 4336511
Issued on: 06/22/1982
Inventor: Stromswold , et al.

Presetting circuit for the voltage-controlled oscillator of a phase lock loop
Patent #: 4434407
Issued on: 02/28/1984
Inventor: Healey, III , et al.

Phase locked-loop generator with closed-loop forcing function shaper Patent #: 4442412
Issued on: 04/10/1984
Inventor: Smith , et al.

Inventor

Voyce, Kenneth G.

Assignee

The Boeing Company

Application

No. 06/902658 filed on 09/02/1986

US Classes:

342/83, Signal phase or frequency other than pulse repetition frequency (PRF)331/4Search sweep of oscillator

Examiners

Primary: Tarcza, Thomas H.
Assistant: Swann, Tod R.

Attorney, Agent or Firm

Christensen, O'Connor, Johnson & Kindness

International Classes

H03C 3/08 (20060101)
G01S 13/00 (20060101)
G01S 13/34 (20060101)
G01S 7/40 (20060101)
H03C 3/00 (20060101)

Abstract

A circuit and method for generating an output signal having an output frequency that varies linearly with time, and an FM CW radar system utilizing such a circuit. The circuit includes a VCO, a rate detector, a phase detector, a filter and an integrator. The VCO produces an output signal at its output terminal at an output frequency that corresponds to the voltage of a tuning signal applied to the VCO input terminal. The rate detector receives the output signal and produces a rate signal having a rate frequency that corresponds to the rate of change of the output frequency. The phase detector compares the rate signal to a reference signal having a fixed frequency, and produces a correction signal corresponding to the phase difference between the rate and reference signals. The filter filters the correction signal to produce a first current signal, and the integrator integrates the first current signal to produce the tuning signal. The circuit may also include a current source for producing a constant magnitude second current signal, in which case the integrator integrates the combined first and second current signals to produce the tuning signal.

Other References

LaRue A. Hoffman, K. H. Hurlbut, D. E. Kind, H. J. Wintroub, "A 94-GHz Radar for Space Object Identification," IEEE TRANSACTIONS ON MICROWAVE THEORY & TECHNIQUES, vol. MTT-17, No. 12, Dec. 1969, pp. 1145-1149
W. J. Caputi, "Stabilized Linear FM Generator," IEEE TRANSACTIONS ON AEROSPACE & ELECTRONIC SYSTEMS, vol. AES-9, No. 5, Sep. 1973, pp. 670-678
Dan R. Bromaghim, John P. Perry, "A Wideband Linear FM Ramp Generator for the Long-Range Imaging Radar," IEEE TRANSACTIONS ON MICROWAVE THEORY & TECHNIQUES, vol. MTT-26, No. 5, May 1978, pp. 322-325
Peyton Z. Peebles, Jr., "Design of a Highly Linear Closed-Loop FMCW Sweep Generator," Technical Report T-79-78 of U.S. Army Missile Command, Redstone Arsenal, Alabama, Aug. 8, 1979
"Conference on Performance of a Linear FM Radar Transmitter at 35 GHz", Peyton Peebles and A. H. Green, Apr. 1982