| 摘要 |
A radio frequency level control circuit is disclosed having a level controller, a sensor and a variable gain amplifier which are located in a feedback path of the level controller. The level controller forms an output signal by mixing an input signal and a feedback signal in a Gilbert cell. The sensor forms a measuring signal and a reference signal from the output signal. The variable gain amplifier produces a feedback signal from a difference between the measuring signal and the reference signal. The Gilbert cell has a current mirror circuit which is configured to lower the supply voltage of the Gilbert cell and to reflect current from the first stage to the second stage. The current mirror circuit is located between a first stage and a second stage of the Gilbert cell, where the first stage is coupled to the feedback signal and the second stage is coupled to the input signal.
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