Design of Power Dividers using Defected Microstrip Structure and an Analytically Calculated Characteristic Line Impedance

Abstract

In this work, a defected microstrip structure (DMS), methods to calculate the new characteristic impedance of DMS line, and, as an application example, a design of microwave wilkinson power dividers using DMS pattern are described. DMS patterns are inserted for the desirable effects of periodic structure such as size-reduction and increased line width for high characteristic impedance. In order to calculate the proper characteristic impedance of DMS microstrip line, the quarter-wavelength transformer model method and an analytic calculation method are adopted. As an example, the DMS microstrip line with 70.7 characteristic impedance is designed, calculated and inserted into the wilkinson power divider. The size of designed power divider with DMS patterns is only 82% of a reference power divider composed of normal microstrip lines, while the circuit performances are very well preserved even after the size-reduction.