| 摘要 |
PROBLEM TO BE SOLVED: To realize a gain controller of a receiver which supplies a signal of a stable level to a demodulation unit, while reducing a ratio of dependency upon an analog circuit even in a reception environment accompanied with reception signal level variation such as phasing caused by mobile reception or the like. SOLUTION: A tuner selects a signal of a desired band out of input signals, then converts its frequency to an analog demodulation signal, an A/D converter converts the analog demodulation signal into a digital demodulation signal, a power detector calculates a power signal, and a demodulator demodulates the digital demodulation signal. An external speed meter determines a moving state, a controller determines a gain signal in accordance with the moving state, a switch produces a level determination signal from the power signal and the gain signal, a control signal generator generates a control signal from the level determination signal, and a D/A converter converts the control signal into an analog signal and feeds it back to the tuner. COPYRIGHT: (C)2006,JPO&NCIPI
|
