Wideband amplifiers with automatic DEPTH negative feedback DC

摘要

The invention relates to radio engineering, in particular to a radio communication technique, and can be used in broadband amplifiers using bipolar transistors, where required to ensure a low level of harmonic distortion of the signal due to the effect of the detection and determined by the level of the input signal. Summary of the utility model is that of the chain parallel negative feedback DC wideband amplifier for a bipolar transistor, taken along the common-emitter (MA) introduced amplitude limiter, a microcontroller and a digital to analog converter (DAC), as a resistance circuit DC parallel negative feedback digital potentiometer is used as the power source of the amplifier adjustment voltage used to power supply low internal resistance. amplitude limiter input is connected to the collector of the bipolar transistor via a decoupling the DC capacitor, and an output connected to the line input-output port of the microcontroller, second and third lines of the input-output ports of which are connected, respectively, to the control input of the digital circuit potentiometer parallel negative feedback DC and the DAC input, the output of which is connected to the control terminal of the controlled power broadband amplifier for a bipolar transistor. The technical result, which is aimed at achieving the proposed solution, - reduction of the coefficient of compression and the level of the amplitude-phase conversion in broadband amplifiers using bipolar transistors included in the circuit with the MA, in the entire range of operating frequencies.