IEEE Microwave and Wireless Components Letters · 2011 · 126 citations · 6 references
EngineeringRadio FrequencyNotched BandWideband AntennasAntennaRing ResonatorUltra-wideband CommunicationFilter DesignStepped-impedance PortsMicrowave EngineeringUltra Wideband EngineeringBandpass FilterElectromagnetic Compatibility
The paper introduces a novel ultra‑wideband bandpass filter with a notched band based on a ring resonator. The design employs a ring resonator with two stepped‑impedance stubs and interdigital‑coupled asymmetric feed lines to achieve wide bandwidth, low return loss, and a 5‑GHz notch. Measurements show 3‑dB fractional bandwidths of 102.8% and 103.3% with and without the notch, and an 11.14‑dB insertion loss at 5.41 GHz within the UWB.
This letter presents a novel ultra-wideband (UWB) bandpass filter (BPF) with a notched band using a ring resonator. Bandwidths of the ring resonator with two stepped-impedance stubs are calculated by examining the relations between resonant frequencies and the characteristic impedance of the ring. Stepped-impedance ports are used to obtain improved return losses in a high-frequency band. Interdigital-coupled feed lines with an asymmetric structure embedded in the stepped-impedance ports are developed to avoid wireless local-area network (WLAN) signals at 5 GHz band. Measured results show that 3 dB fractional bandwidths (FBWs) are 102.8% and 103.3% with and without the notched band, respectively. Measured insertion loss of the notched band within the UWB is 11.14 dB at 5.41 GHz.
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