A lossy three-pole microstrip bandpass filter using an extended doublet network is proposed in this letter. Nonuniform Q distribution is considered by reducing the of one resonator, resulting in a flatter passband with an enhanced selectivity. Also, the novel feeding network adopted brings about two extra transmission zeros and a wide stopband that further improve the filter performance. Good agreement between the simulated and measured results can be observed to validate the design.
- Extended doublet
- lossy circuit technique nonuniform Q distribution
- microstrip filter
- transmission zeros
- MICROWAVE FILTERS