| 摘要 |
A frequency hopping receiver circuit has a frequency converter (12) and a hopping control circuit (14) coupled to the frequency converter (12), and configured to control frequency hopping of the received frequency, by controlling changes in frequency shift applied by the frequency converter (12). The frequency change is applied in combination with a temporary reduction in conversion gain of the frequency converter (12) during the change in frequency shift. The frequency converter may contain a mixer (122), a local oscillator circuit (120) and a controllable amplifier (124) coupled between the input of the frequency converter (12) and the mixer (122) or between the mixer (122) and the output of the frequency converter (12), or between the local oscillator circuit (120) and the local oscillator input of the mixer (122). In this case the hopping control circuit (14) has outputs coupled to a gain control input of the controllable amplifier (124) and a frequency control input of the local oscillator circuit (120), to control the reduction in conversion gain and the change in frequency shift respectively.
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