New wideband microstrip bandpass filter using single triangular patch resonator with fractal-shaped defection

New equilateral triangular patch resonator bandpass filters using fractal defection are presented to implement high performances of wide passband, transmission zeros, and low passband insertion losses. Using fractal defection acts as perturbation, filter performances are greatly enhanced, and the validity of the design is demonstrated by measurement. Compared with some reported dual-mode or multi-mode filters, the new filters still have nicer performances even though operate at a single mode, simultaneously, have more compact and simple structures for having single patch resonator without coupling gaps.