SELECTIVE AMPLIFIER Russian patent published in 2012 - IPC H03F3/00 

FIELD: physics, radio.

SUBSTANCE: present invention relates to radio engineering and communication and can be used in devices for microwave filtration of radio signals of cellular communication systems, satellite television, radar etc. In some cases, the invention enables to reduce total power consumption and realise a high-quality selective microwave device with f₀=1-5 GHz. To this end, the selective amplifier has a signal source (1) connected to the input (2) of the device, a first (3) input transistor, whose collector is connected through a first (4) current-stabilising two-terminal device to the first (5) power supply bus and the input of an additional current mirror (6), the current output of which is connected through a first (7) frequency-setting resistor to the first (5) power supply bus, a first (8) balancing capacitor, connected through alternating current in parallel to the first (7) frequency-setting resistor, a second (9) current-stabilising two-terminal device, connected between the emitter of the first (3) input transistor and the second (10) power supply bus, a second (11) input transistor. Between the emitter of the first (3) and second (11) input transistors, there are series-connected second (12) balancing capacitor and second (13) frequency-setting resistor, the base of the second (11) input transistor is connected to the input (2) of the device, the collector is connected to the first (5) power supply bus, and the emitter is connected to the second (10) power supply bus through a third (14) current-stabilising two-terminal device, wherein a voltage repeater is connected between the output of the device and the base of the first (3) input transistor.

EFFECT: high Q-factor of the amplitude-frequency curve of the selective amplifier and its voltage gain at quasi-resonance frequency f₀.

4 cl, 12 dwg