Super-compact stopband filter based on grounded patch resonator

A novel compact stopband microstrip filter is proposed, based on the grounded patch resonator embedded in the microstrip line. Characteristics of the proposed filter are compared with state-of-the-art stopband filters of similar type in terms of size, performance and fabrication complexity. The fabricated fourth-order filter has overall dimensions of 0.52??g ?? 0.13??g, 10 dB fractional bandwidth equal to 35 at 4.36 GHz, and insertion loss of more than 30 dB in the stopband, and it outperforms all previously published stopband filters of that type.