PORTABLE RADIO TRANSMITTER HARMONICS FILTER Russian patent published in 2020 - IPC H03H7/09 

FIELD: radio engineering and communications.

SUBSTANCE: invention relates to radio engineering and can be used in output devices of power amplifiers of wide-range radio transmitters. Frequency band of the portable radio transmitter is divided into N subbands, and the radio transmitter contains N low-pass filters (LPF) switched on the input and output by means of input and output three-contact switches. Each LPF contains three inductance coils, two of which are connected in series to each other and connected by an inductive coupling to the third inductance coil, wherein all three inductance coils are arranged on two cores of toroidal shape and have the same winding direction. Third inductance coil comprises K turns of wire, equal to number of passes of wire through holes of first and second toroidal cores during winding, where K=1, 2, 3, … is an integer.

EFFECT: expansion of short-wave range of a radio transmitter with simultaneous increase of its reliability.

3 cl, 1 dwg