BANDPASS TUNABLE MICROWAVE FILTER Russian patent published in 2012 - IPC H01P1/203 

FIELD: electricity.

SUBSTANCE: device comprises two transfer lines with identical wave resistances (R), one is designed for entry of a microwave signal, the other one - for exit, at least one link of a microwave filter with two field transistors (FT) with a Schottky barrier. FT gates with a Schottky barrier are connected with a source of DC control voltage, a source of one FT with a Schottky barrier is grounded. Each link is provided with two inductances (I), two capacitances (C) and two identical resistors with an R value each, equal to a tenfold value of a wave R at the inlet or outlet of the microwave filter. One end of the first C is connected to a transmission line at the inlet, the other one - with a source of the first FT with a Schottky barrier and with one end of the first I, its other end is grounded. The drain of the first FT with a Schottky barrier is connected to one end of the second I, the other end of the second I is connected with one end of the second E. The other end of the second E is connected to the drain of the second FT with a Schottky barrier. The source of the second FT with a Schottky barrier is grounded. The gate of each FT with a Schottky barrier via an appropriate resistor is connected to a control DC voltage source.

EFFECT: reduced coefficient of a standing voltage wave and higher steepness of fronts of amplitude-frequency characteristics of a microwave filter, with preservation of a wide range of frequency tuning and low microwave losses in a pass band.

2 cl, 4 dwg