THz CONTROLLED DUPLEX ISOLATOR

Abstract

The paper studies the devices of THz frequency range for modern telecommunication. There has been presented a two-frequency duplex isolator constructed on the basis of anisotropic layered structure with arbitrary direction of anisotropic axis. Such device is widely used in antenna-feeder paths for decoupling of transmitted and received signals. The isolator consists of two transceiving antennas, two solenoids and an anisotropic plate. Its basic element is an anisotropic plate having nonreciprocal properties. The optimum isolator structure includes twelve two-layer periods and provides the best nonreciprocal properties. The operation principle of the isolator is determined not by Faraday's effect, but by dependence of structural parameters on the direction and size of external magnetic field. Such approach allows to pass a wave of the defined working frequency in one (straight) direction and not to pass this wave in the return direction. At the same time, the wave at another working frequency can extend only in the return direction and can’t extend directly. The offered device has selective properties as well. In fact, the integrated device combines the duplex two-frequency isolator and the strip filter. To calculate general characteristics there were used the matrix method of transformation and matrix method of reflection. Dependences of duplex isolator characteristics on direction of falling a harmonious wave and anisotropic axis orientation have been presented. There have been given calculation results of wave numbers in a uniform ferrite layer and dependences of reflection coefficients