Microstrip gunn oscillator with varactor tuning

• US 4,034,313 A
• Filed: 05/14/1975
• Issued: 07/05/1977
• Est. Priority Date: 05/20/1974
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Jones, Stewart Barry, Williams, Keith Rushworth
• Primary Examiner(s): Grimm, Siegfried H.
• Application Number:
  US05/577,315
• Time in Patent Office: 783 Days
• Field of Search: 331/96, 331/99, 331/107 R, 331/107 G, 331/177 V, 343/5 R, 343/17.1, 333/1.1, 333/24.1, 333/82R
• US Class Current: 331/96
• CPC Class Codes: H03B 9/141 and comprising a voltage sensitive element, e.g. varactor

Abstract

A microwave oscillator arrangement comprising a microstrip resonator, a Gunn oscillator mounted outside the substrate of the resonator, a varactor diode connected in series with the Gunn oscillator and the resonator, and means for applying adjustable bias to the varactor diode.

Claims

1. A microwave oscillator arrangement comprising a dielectric substrate, a microstrip resonator formed on a portion of the substrate, a negative-resistance oscillator device external to the resonator, means for coupling the negative-resistance oscillator device to the resonator, whereby substantially all the R.F. power produced by the negative-resistance oscillator device is fed into the resonator, means for coupling R.F. power out of the resonator into a load, and a variable reactance connected in series between the negative-resistance oscillator device and the resonator whereby to adjust the operating frequency of the oscillator arrangement.

2. An oscillator arrangement as claimed in claim 1 wherein the resonator is a length of microstrip line.

3. An oscillator arrangement as claimed in claim 2 wherein the microstrip line is open circuited.

4. An oscillator arrangement as claimed in claim 3 wherein the variable reactance is connected to one end of the microstrip line.

5. An oscillator arrangement as claimed in claim 1 wherein the means for coupling power out of the resonator comprises a capacitor.

6. An oscillator arrangement as claimed in claim 5 wherein the capacitor comprises a gap between the resonator and a further strip line.

7. An oscillator arrangement as claimed in claim 1 wherein the means for coupling R.F. power out of the resonator is immediately adjacent a connection of the means for coupling the negative-resistance device to the resonator.

8. An oscillator arrangement as claimed in claim 1 wherein the means for coupling the negative-resistance device to the resonator comprises a wire.

9. An oscillator arrangement as claimed in claim 1 wherein the variable reactance is a varactor.

10. An oscillator arrangement as claimed in claim 1 wherein the negative-resistance device is an unencapsulated Gunn device.

11. An oscillator arrangement as claimed in claim 10 wherein the Gunn device is mounted on a thermally conductive screw.

12. An oscillator arrangement as claimed in claim 1 comprising means for varying the reactance so as to reduce a variation of operating frequency with temperature.

13. An oscillator arrangement as claimed in claim 12 wherein the means for varying the reactance comprises a thermistor.

14. An oscillator arrangement as claimed in claim 1 comprising a distributed low-pass filter for applying a D.C. voltage to the negative-resistance device.

15. An oscillator arrangement as claimed in claim 1 comprising a distributed low-pass filter for applying a D.C. voltage to the variable reactance.

16. An oscillator arrangement as claimed in claim 1 comprising a gyromagnetic isolating device, having a plurality of ports and wherein the means for coupling R.F. power out of the resonator is arranged to couple the R.F. power into a first port of the isolating device.

17. An oscillator arrangement as claimed in claim 16 wherein the isolating device is a three-port circulator and wherein a mixer diode is coupled to a second port of the circulator relatively isolated from the first port.

18. An oscillator arrangement as claimed in claim 17 comprising a distributed low-pass filter connected to the mixer diode.

19. An oscillator arrangement as claimed in claim 16 wherein the isolating device is a three-port circulator and wherein a matched load is connected to a second port of the circulator relatively isolated from the first port.

20. An oscillator arrangement as claimed in claim 1 wherein the resonator is formed on a ferrite substrate.