FREQUENCY SELECTIVE DEVICE Russian patent published in 2011 - IPC H04B1/18 

FIELD: radio engineering.

SUBSTANCE: to frequency selective device including band-pass filter tunable in frequency band by means of variable capacitors and containing M band-pass double-circuit links with inductive coupling between circuits, as well as input and output matching links there introduced are additional band-pass tunable filters (BTF) and (2M×N)+2N three-contact switches, where N - number of BTF (frequency subrange). In each of BTF the band-pass links are the same and contain two L-shaped semi-links with inductance coil in longitudinal arm and capacitor in transverse arm. Inductance coils of L-shaped semi-links are connected to each other, and to their connection point there connected is one communication inductance output, the second output of which is connected to common bus.

EFFECT: enlarging the range of working frequencies of frequency selective device and minimising the changes of its parameters at tuning.

3 cl, 2 dwg