TUNABLE REJECTION LC FILTER Russian patent published in 2013 - IPC H03H9/00 H03H7/12 

FIELD: radio engineering, communication.

SUBSTANCE: device includes a low-pass filter consisting of N structurally identical links, each link consisting of an inductance coil, the first lead of which is the input of the link, the second lead is the output of the link; each of the leads of the inductance coil is connected to a capacitor; the second leads of the capacitors are connected to a common bus, wherein two loops are further included, each consisting of parallel-connected capacitor and inductance coil; also additionally included are first, second, third and fourth signal lines; the second signal line is connected to a first group of M electronic switches; the second lead of each electronic switch is connected to a capacitor; the second leads of the capacitors are connected to the first signal line, and the third signal line is connected to a second group of M electronic switches; the second lead of each of the electronic switches is connected to a capacitor; the second leads of the capacitors are connected to the fourth signal line.

EFFECT: providing an electronically tunable rejection band in the operating frequency band.

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