Microstrip two-loop directional coupler with special characteristics

Some interest to a relatively poorly studied class of directional couplers, namely transoriented type, has recently been designated. Above all it deals with couplers modifications on strongly linked lines. It should be borne in mind that the self-directed type of trance a loop coupler is performed relatively infrequently, because it can be directly implemented on the basis of co-current type. However, in some cases within the framework of a single topology and without switching outputs, it is required to implement both types of focus. This combination of properties can be very essential in charting forming schemes of phased array antennas. In this paper, the authors propose a loop topology of the microstrip directional coupler, which provides two types of focus (co-directional and transoriented) in adjacent frequency bands. Co-directional power branch is provided at frequencies from 0.85 to 0.95 GHz, transoriented - from 2.4 to 2.5 GHz. Electromagnetic simulation of the proposed coupler has demonstrated its efficiency and satisfactory characteristics of both interchange and harmonization, as well as on the transition easing. To optimize the performance of the coupler the electrical equivalent circuit of lumped elements, linked with the geometric parameters of components topology is generated. The local relations are obtained for the s parameters of the coupler are obtained by the method of mirror images. The comparison of the results of the electrodynamic and mathematical simulation of the coupler is carried out. These testing results show the adequacy and effectiveness of the model, as well as they confirm the performance and conformation to the electrical parameters of the proposed coupler circuit.