Triangular Patch Resonator Bandpass Filter with Higher Order Mode Operation

w microstrip bandpass filters with higher order mode operation by using single triangular patch resonator are developed to perform wide passbands and stopbands, low passband insertion loss and transmission zeros, et al. With a fractal defection acts as perturbation, filter operation frequency can be controlled, and the responses of undesired modes can be greatly weakened even suppressed. The proposed filters have outstanding advantages of single patch with compact size without resonator coupling gaps, nicer performances and miniaturization, and all these features are well popular for wireless communication systems.