Self-calibrating temperature-compensated frequency source
First Claim
1. A method of operating a frequency source, comprising the steps of:
- receiving an external reference frequency signal when available and controlling the frequency source to lock the operating frequency of the frequency source to the reference frequency signal;
during operation of said frequency source when said external reference frequency is being received, detecting temperature of the frequency source and storing temperature information relating to detected temperatures and control information relating to control settings required to maintain frequency lock for the detected temperatures; and
when said external reference frequency signal is not being received, detecting the temperature of said frequency source and utilising the stored temperature and control information to provide a control setting in accordance with the detected temperature, for controlling the operating frequency of the frequency source.
2 Assignments
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Accused Products
Abstract
A frequency source (1) in, for example, a remote unit in a mobile communications system, is controlled to maintain a stable frequency signal. In normal operation, the frequency source (1) is frequency locked to an external reference frequency (10). A temperature detecting device (2) monitors the temperature of the frequency source, and information relating to temperature is stored in a storage device (7) together with information relating to control signals (6) applied to the frequency source (1). In the absence of the reference frequency (10), the temperature of the frequency source (1) is detected and the stored information is used to generate a control signal (6) to control the output frequency of the frequency source (1) in accordance with the detected temperature.
33 Citations
27 Claims
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1. A method of operating a frequency source, comprising the steps of:
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receiving an external reference frequency signal when available and controlling the frequency source to lock the operating frequency of the frequency source to the reference frequency signal; during operation of said frequency source when said external reference frequency is being received, detecting temperature of the frequency source and storing temperature information relating to detected temperatures and control information relating to control settings required to maintain frequency lock for the detected temperatures; and when said external reference frequency signal is not being received, detecting the temperature of said frequency source and utilising the stored temperature and control information to provide a control setting in accordance with the detected temperature, for controlling the operating frequency of the frequency source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. Apparatus for operating a frequency source, comprising;
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means for receiving an external reference frequency signal when available; control means for controlling the frequency source to lock the operating frequency thereof to the external reference frequency signal; temperature detecting means for detecting the temperature of the frequency source; storage means for storing, during operation of the frequency source, when said external reference frequency signal is being received, temperature information relating to detected temperatures and control information relating to control settings required to maintain frequency lock for the detected temperatures; and control setting providing means for providing a control setting to control the operating frequency of the frequency source when no external reference frequency signal is being received, said control setting means utilising the stored temperature and control information to provide the control setting in accordance with the detected temperature. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification