Title:
【発明の名称】ヘテロダイン無線受信機における発振器の自動較正
Document Type and Number:
Japanese Patent JP2814638
Kind Code:
B2
Abstract:
There is provided a system for automatically and integrally calibrating an oscillator 10 to achieve frequency accuracy and stability in a radio, particularly a radio where the temperature of an oscillator can be set. For calibration or setting up of an oscillator 10 subject to error in output frequency, the radio is tuned to a calibration frequency received from a transmitted frequency standard or a precision test instrument. The frequency error of 10 is multiplied as a result of conversion to the baseband via mixers 14, 16 and a demodulator 20. The baseband frequency is measured by digital frequency sampling in a microprocessor included in a processor 18. The microprocessor applies frequency control signals to the oscillator 10 via a D/A converter until the frequency deviation measured at the demodulator 20 output disappears. The final output of D/A converter is stored in a non-volatile memory. The oscillator 10 may be an oven temperature controlled crystal oscillator.
Inventors:
Schwarzman, Zalman
Shapira, Yaia
Shani, alex
Berry liner, Shlomo
Berman, Schmuell
Leak, Schmuell
Shapira, Yaia
Shani, alex
Berry liner, Shlomo
Berman, Schmuell
Leak, Schmuell
Application Number:
JP50639689A
Publication Date:
October 27, 1998
Filing Date:
May 25, 1989
Export Citation:
Assignee:
Motorola Incorporated
International Classes:
H03B5/32; H03D7/16; H03H3/04; H03H9/02; H03L1/02; H03L7/08; H03L7/10; H04B1/26; H04B17/00; (IPC1-7): H03L1/02; H03B5/32; H03H3/04; H03H9/02; H04B1/26; H04B17/00
Domestic Patent References:
| JP623527A | ||||
| JP62116003A | ||||
| JP61220527A | ||||
| JP60115906A | ||||
| JP5654111A | ||||
| JP6247240U | ||||
| JP6355614U | ||||
| JP53152513U | ||||
| JP60149240U | ||||
| JP60121312U | ||||
| JP62199804U |
Other References:
【文献】米国特許4746879(US,A)
【文献】米国特許4677394(US,A)
【文献】米国特許4677394(US,A)
Attorney, Agent or Firm:
Masanori Honjo (1 person outside)