Low cost and compact wideband microwave notch filter based on miniaturized complementary metaresonator

Abstract

In this paper, low cost, small size and wideband microwave notch filter with good peak attenuation based on complementary circular spiral resonator (CCSR) is realized analytically, calculated numerically and verified experimentally. Fundamental frequency of the proposed filter is 2.47 GHz with notch depth − 13.89 dB and unloaded Q factor 49.4. The electrical size of CCSR structure is $$\lambda g/12$$ which is very high level of miniaturization. The effects of resonator dimensions, substrate thickness and number of CCSR structures on resonance frequency, notch depth, bandwidth and unloaded Q factor are analyzed in detail. After optimization of different design parameters, an optimized filter is designed which has resonance frequency 2.47 GHz with notch depth − 52.38 dB and unloaded Q factor 83. To verify the concept, prototypes of first- and fourth-stage filters are fabricated and tested using vector network analyzer AV3672. Simulated and measured results are very close to each other.