Split-distributed resonators and filters

In this paper, an inline, 5-pole filter realized using split-distributed resonant elements is presented. The filter is made to operate at the frequency of 1.8 GHz, with an absolute bandwidth of 40 MHz. Each resonator of the proposed filter consists of 9 split-distributed resonant elements, placed in close proximity. The chamber size of each resonator is 30 mm x 30 mm x 7 mm, with an unloaded quality factor of over 1900. The measured insertion loss of the filter is 0.94 dB, which is in excellent agreement with the theoretically predicted value of 0.76 dB.