HARMONIC FILTER FOR SHORT-WAVE TRANSMITTER Russian patent published in 2015 - IPC H03H7/09 

FIELD: radio engineering, communication.

SUBSTANCE: harmonic filter for a short-wave receiver comprises N middle inductance coils, where N is the number of frequency subbands, a first variable capacitor connected to the first terminal of each middle inductance coil through one of N first switches, and a second variable capacitor connected to the second terminal of each middle inductance coil through one of N second switches, N input L-shaped links, each consisting of two inductance coils, the connection point of which is connected to the first terminal of the corresponding middle inductance coil, wherein the input inductance coil of the input L-shaped link is inductively coupled with a middle inductance coil, and N output L-shaped links, each consisting of two inductance coils, the connection point of which is connected to the second terminal of the corresponding middle inductance coil.

EFFECT: matching a harmonic filter in the entire operating frequency band of a radio transmitter and increasing the transmission coefficient while reducing the level of harmonic components of the transmitted signal.

4 cl, 1 dwg