| 摘要 |
A modulated carrier signal, the amplitude variations of which are smaller than the amplitude of the unmodulated carrier, is not very suitable for transmission over radio links because the required use of non-linear components, such as class-C amplifiers, result in an unwanted widening of the transmitted spectrum. According to the invention an arrangement for amplifying such a signal comprises two oscillators (16, 17) the desired relative phase of which is adjusted in a loop including a control circuit 22. On combining the oscillator signals v'k and v'g, there is produced a resulting signal r which is a replica of the input signal v having the amplitude variations. As the oscillators 16 and 17 produce signals having a constant amplitude, these signals can be easily amplified, for example by class-C amplifiers. |
