A dual-mode rectangular ring bandpass filter with transmission zeros on LTCC

The dual-mode rectangular ring resonator has been described and analyzed. The dual-mode resonance, transmission-zero frequencies and bandwidth can be predicted using proposed equations. The shunt capacitors of bends in this structure will shift the transmission zero frequencies, therefore they should be included in the analysis equations. By tuning the aspect ratio of rectangular ring, we can control dual-mode resonance, transmission-zero frequencies and bandwidth. The experiment and EM simulation results of a LTCC ring filter show the validity of proposed analysis method.