Novel Quasi-Elliptic Function Bandpass Filter Using Hexagonal Resonators with Capacitive Loading

ETRI Journal

关键词: open stub;    slot;    elliptic-function bandpass filter (BPF);    Hexagonal open-loop resonator;   

Others  :  1185668
DOI  :  10.4218/etrij.08.0208.0111

【 摘 要 】

A novel and compact elliptic-function bandpass filter is proposed in this letter. The techniques of slot etching and the addition of open stubs are applied to enhance the self-inductance and self-capacitance of hexagonal open-loop resonators. Thus, size reduction and improved transmission performance are obtained. Compared to the performance of the conventional design, the central frequency and insertion loss are reduced by 28% and 3.1 dB, respectively. Measurements show that the proposed filter has a fraction bandwidth of 23% at the central frequency of 1.84 GHz, and its insertion loss in the passband is less than -1.5 dB. The bandpass filter occupies only 12 mm×21.2 mm (approximately 0.24λg×0.14λg).

   

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