A CAD assisted design methodology for wide-band arbitrary power division coupler implemented in microstrip technology

A design methodology for wide-band coupler with arbitrary power division ratio is presented. The proposed design has two design variables that can be chosen independently. This availability of free variable provides opportunity to obtain design parameters for a possible implementation in native microstrip technology. The two design variables can be tuned with the assistance of CAD to choose appropriate design parameters. While the design methodology is illustrated using unequal power division ratio, to show practical utility a 3-dB coupler is designed and fabricated on FR-4 substrate. The effectiveness of the proposed strategy is exhibited from simulated and measured results. Moreover, effect of substrate is also demonstrated through example.