Design and Fabrication of Ultra Wide-Band Bandpass Filters with Notched-Band using a Rectangular Ring Resonator

In this work, Ultra Wide-Band (UWB) microwave filters are designed and fabricated using a rectangular ring resonator. The UWB microwave filters work in the 3.1GHz to 10.6GHz frequency band, which is designed to coverage the FCC frequency spectrum for UWB systems. These filters, in addition to being ultra-wideband, are designed to prevent interference in some frequency bands, such as WiMAX band (3.5GHz), WLAN band (5.2-5.8GHz) and satellite communication systems (8GHz) band. For this reason, in designing these filters intelligently, it is necessary to take precautions to ensure producing narrow and precise notches in the frequency response to prevent interference. This broad bandwidth and narrow notches with adjusted even or odd mode resonator frequencies, can be controlled by varying the characteristic impedance of the rectangular ring resonator. The proposed structures are simulated and optimized using HFSS software, so that the results of fabrication and measurement of these filters have an excellent agreement with the simulation results.