FREQUENCY-SELECTIVE DEVICE Russian patent published in 2014 - IPC H03H7/01 

FIELD: radio engineering, communication.

SUBSTANCE: frequency-selective device has, in its middle part, N switchable and tunable LC filters, each having in the longitudinal arm an inductance coil and in transverse arms first and second variable capacitors, respectively, that are common for all LC filters, and each LC filter includes an additional input inverted L-shaped half-link consisting of an inductance coil and a capacitor, the point of connection of which is connected to the first lead of the inductance coil of the LC filter, and an output inverted L-shaped half-link consisting of an inductance coil and a capacitor, switches and a step-down autotransformer.

EFFECT: low attenuation in the transmission band, high attenuation in the stop-band of the frequency-selective device and minimising changes in parameters thereof when tuning in the operating frequency range.

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