Patent ID: 6664856
Filing Date: 2003-12-16
Classification: H03F

Abstract:
A circuit configuration for setting an operating point of a radiofrequency transistor having a load current path and a control terminal, comprising:a terminal for a first supply potential and a terminal for a second supply potential; a measurement terminal for connection to a measuring resistor connected in series with the load current path of the radiofrequency transistor; an output terminal for connection to the control terminal of the radiofrequency transistor; a reference voltage source; a differential element having supply voltage terminals connected to said terminal for said first supply potential and to said terminal for said second supply potential, a first signal input connected to said reference voltage source, and a second signal input connected to said measurement terminal; a current source connected to and controllable by said differential element and connected to said output terminal; a first resistor connected to said terminal for the first supply potential and a second resistor connected to said terminal for the first supply potential; a current source connected to said terminal for the second supply potential; a current mirror circuit having an input path connected to said current source, an output path connected to said terminal for the first supply potential through said first resistor, and a control line coupling said input path to said output path; a transistor having a base connected to said control line and an emitter connected through said second resistor to said terminal for the first supply potential and to said measurement terminal.