Space vehicle with temperature sensitive oscillator and associated method of sensing temperature in space

• US 6,390,672 B1
• Filed: 01/20/2000
• Issued: 05/21/2002
• Est. Priority Date: 01/20/2000
• Status: Expired due to Fees

• Current Assignee: Xd Semiconductors LLC (Intellectual Ventures LLC)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Vail, David K., Hinshaw, Thornton
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): DEJESUS, LYDIA M
• Application Number:
  US09/488,628
• Time in Patent Office: 852 Days
• Field of Search: 374/170, 374/171, 701/13, 331/66, 331/111
• US Class Current: 374/170
• CPC Class Codes: G01K 7/245 in an oscillator circuit

Abstract

A space vehicle includes a temperature sensitive oscillator carried by a housing. The temperature sensitive oscillator includes a radiation hardened inverting gain circuit, such as a comparator, able to withstand radiation in an ambient space environment, and a thermistor connected to the radiation hardened inverting gain circuit so that an output frequency of the temperature sensitive oscillator varies based upon a temperature of the thermistor. Also, a frequency counter is preferably connected to the temperature sensitive oscillator for generating a digital output signal representative of a sensed temperature. The sensed temperature may be used by one or more electronic circuits connected to the frequency counter.

Claims

1. A space vehicle comprising:

a housing;

a temperature sensitive oscillator carried by said housing and comprising

a radiation hardened inverting gain circuit able to withstand radiation in an ambient space environment, and

a thermistor connected to said radiation hardened inverting gain circuit so that an output frequency of said temperature sensitive oscillator varies based upon a temperature of said thermistor;

a frequency counter connected to said temperature sensitive oscillator for generating a digital output signal representative of a sensed temperature; and

at least one electronic circuit connected to said frequency counter and using the sensed temperature therefrom.

2. A space vehicle according to claim 1 wherein said frequency counter is radiation hardened.

3. A space vehicle according to claim 1 wherein said radiation hardened inverting gain circuit comprises a radiation hardened comparator.

4. A space vehicle according to claim 3 wherein said radiation hardened comparator comprises a plurality of transistor gates, each having a radiation hardened structure.

5. A space vehicle according to claim 1 wherein said radiation hardened inverting gain circuit comprises an output and an input;

and wherein said thermistor is connected between the output and input of said radiation hardened inverting gain circuit.

6. A space vehicle according to claim 5 wherein the input comprises an inverting input.

7. A space vehicle according to claim 1 wherein said thermistor is collocated with said radiation hardened inverting gain circuit.

8. A space vehicle according to claim 7 wherein said temperature sensitive oscillator has an operating temperature range of about −

55 to 70°

C.

9. A space vehicle according to claim 1 wherein said thermistor is remotely positioned from said radiation hardened inverting gain circuit.

10. A space vehicle according to claim 9 wherein said temperature sensitive oscillator has an operating temperature range of about −

80 to 300°

C.

11. A space vehicle according to claim 1 further comprising a calibration processor connected between said frequency counter and said at least one electronic circuit.

12. A space vehicle according to claim 1 further comprising a phased array antenna carried by said housing;

and wherein said at least one electronic circuit comprises a phased array antenna control circuit connected to said phased array antenna.

13. A space vehicle comprising:

a housing;

a temperature sensitive oscillator carried by said housing and comprising

a radiation hardened comparator able to withstand radiation in an ambient space environment, and

a thermistor connected to said radiation hardened comparator so that an output frequency of said temperature sensitive oscillator varies based upon a temperature of said thermistor;

a frequency counter connected to said temperature sensitive oscillator for generating a digital output signal representative of a sensed temperature; and

a calibration processor connected to said frequency counter and for processing the digital output signal therefrom.

14. A space vehicle according to claim 13 wherein said frequency counter is radiation hardened.

15. A space vehicle according to claim 13 wherein said calibration processor is radiation hardened.

16. A space vehicle according to claim 13 wherein said radiation hardened comparator comprises a plurality of transistor gates, each having a radiation hardened structure.

17. A space vehicle according to claim 13 wherein said radiation hardened comparator comprises an output and an input;

and wherein said thermistor is connected between the output and input of said radiation hardened comparator.

18. A space vehicle according to claim 17 wherein the input comprises an inverting input.

19. A space vehicle according to claim 13 wherein said thermistor is collocated with said radiation hardened comparator.

20. A space vehicle according to claim 19 wherein said temperature sensitive oscillator has an operating temperature range of about −

55 to 70°

C.

21. A space vehicle according to claim 13 wherein said thermistor is remotely positioned from said radiation hardened comparator.

22. A space vehicle according to claim 21 wherein said temperature sensitive oscillator has an operating temperature range of about −

80 to 300°

C.

23. A space vehicle according to claim 13 further comprising at least one electronic circuit connected to said calibration processor and using a temperature value therefrom.

24. A space vehicle according to claim 23 further comprising a phased array antenna carried by said housing;

and wherein said at least one electronic circuit comprises a phased array antenna control circuit connected to said phased array antenna.

25. A temperature sensor for sensing temperature in an ambient space environment and comprising:

a temperature sensitive oscillator comprising

a radiation hardened inverting gain circuit able to withstand radiation in the ambient space environment, and

a thermistor connected to said radiation hardened inverting gain circuit so that an output frequency of said temperature sensitive oscillator varies based upon a temperature of said thermistor.

26. A temperature sensor according to claim 25 further comprising a frequency counter connected to said temperature sensitive oscillator for generating a digital output signal representative of a sensed temperature.

27. A temperature sensor according to claim 26 wherein said frequency counter is radiation hardened.

28. A temperature sensor according to claim 25 wherein said radiation hardened inverting gain circuit comprises a radiation hardened comparator.

29. A temperature sensor according to claim 25 wherein said radiation hardened inverting gain circuit comprises an output and an input;

and wherein said thermistor is connected between the output and input of said radiation hardened inverting gain circuit.

30. A temperature sensor according to claim 29 wherein the input comprises an inverting input.

31. A temperature sensor according to claim 25 wherein said thermistor is collocated with said radiation hardened inverting gain circuit.

32. A temperature sensor according to claim 31 wherein said temperature sensitive oscillator has an operating temperature range o f about −

55 to 70°

C.

33. A temperature sensor according to claim 25 wherein said thermistor is remotely positioned from said radiation hardened inverting gain circuit.

34. A temperature sensor according to claim 33 wherein said temperature sensitive oscillator has an operating temperature range of about −

80 to 300°

C.

35. A method for sensing a temperature associated with a space vehicle in an ambient space environment comprising the steps of:

providing a temperature sensitive oscillator comprising a radiation hardened inverting gain circuit and a thermistor connected thereto;

exposing the thermistor to an ambient temperature to be sensed so that a frequency of the temperature sensitive oscillator varies based upon the sensed temperature; and

counting the frequency of the temperature sensitive oscillator to generate a digital output signal representative of a sensed temperature.

36. A method according to claim 35 further comprising the step of processing the digital output signal to obtain a temperature value therefrom.

37. A method according to claim 35 wherein the step of counting the frequency comprises providing a radiation hardened frequency counter.

38. A method according to claim 35 wherein said radiation hardened inverting gain circuit comprises a radiation hardened comparator.

39. A method according to claim 38 wherein said radiation hardened comparator comprises an output and an input;

and wherein said thermistor is connected between the output and input of said radiation hardened comparator.

40. A method according to claim 39 wherein the input comprises an inverting input.

41. A method according to claim 35 wherein said thermistor is collocated with said radiation hardened inverting gain circuit.

42. A method according to claim 41 wherein said temperature sensitive oscillator has an operating temperature range of about −

55 to 70°

C.

43. A method according to claim 35 wherein said thermistor is remotely positioned from said radiation hardened inverting gain circuit.

44. A method according to claim 43 wherein said temperature sensitive oscillator has an operating temperature range of about −

80 to 300°

C.