Design of Balanced Filtering Components Based on Isosceles Right-Angled Triangular Patch

In this paper, a balanced bandpass filter (BPF), a balanced-to-balanced filtering power divider (FPD), and a halun filter are implemented using the isosceles right triangular patch element. Two isosceles right triangular patch elements are coupled through an open stub for a triple-mode passband response wider differential-mode operation and wide commonmode suppression simultaneously. To further improve the selectivity, an open stub is loaded on each feed-line. Based on these elements, a balanced BPF with excellent performance can be implemented. As an extension, a balanced-to-balanced FPD and a halun BPF are implemented based on the structure of the filter. For validation of the proposed configurations, all the balanced BPF, FPD, and balun BPF have been fabricated and measured. All measured results are found to he in a reasonable agreement with the simulation results.