Analysis and Modeling of a Directional Microwave Coupler as SMD Component

Abstract

The article describes the calculation, modeling and layout of the directional coupler. In the course of the work the market analysis was carried out, the model of directional coupler in the frequency range of 2.9—4.5 GHz, the layout of the device and measuring equipment were developed. Directional couplers with different transient attenuation are widely used in the distribution circuits of antenna arrays, as well as to control the power of the radio signal propagating in the transmission line, in power meters, automatic gain control systems, radio receivers, etc. The choice of circuit solutions used for the construction of directional couplers is carried out depending on the specific technical requirements for electrical parameters, the range of operating frequencies and the capabilities of the technological base. Practically all variety of structures of directional couplers realized on elements is a result of modification of the simplest structures. The main types of directional taps include stub, single-stage and tandem-based. During the simulation, it turned out that the directional coupler based on a tandem connection of two connected transmissions with the location of the transmission lines on different layers of the multilayer printed section was suitable for this work. This is due to the fact that when modeling the directional coupler with transmission lines on one printed circuit board, The gap between these lines is too small (&10 nm), which is extremely difficult to perform on a microstrip structure.