| 摘要 |
The process involves transforming the modulation frequency to a phase modulation (C3), so that the carrier frequency follows a path (3) in a delay circuit as a function of the instantaneous modulated frequency. A difference in the phase ( phi i) of modulation is detected (5), and the phase of the delayed carrier is compared with phase of a non-delayed carrier. The method also involves converting (5) the difference in phase ( phi i) to an amplitude (Ai) of the demodulation signal which varies according to the phase difference ( phi i) and represents the amplitude (Ai) of the excitation signal. The demodulation signal is subjected to low-pass filtering (6). The amplitude (Ai) of the modulation signal is augmented according to the modulation frequency dynamic (F0- DELTA F, F0+ DELTA F), by augmenting the difference in phase ( phi i) obtained by reducing the speed of propagation of the modulated carrier on a delay path (3) using a surface wave device.
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