Abstract
A new wideband bandpass filter configuration with input-output cross-coupling is investigated. The new filter is based on a transmission line filter with short-circuited stubs. In order to allow the filter to exhibit high selectivity filtering characteristic and to enhance the group delay with only a few resonators, cross-coupling between the input and output feed lines is introduced. As a result, new symmetrical pairs of transmission zeros are generated at the lower and upper stopbands, leading to a quasi-elliptic function response that improves the passband and out-of-band performances. A general circuit model for the proposed filter is presented and a demonstrator with approximately 48% ripple bandwidth at a midband frequency of 3 GHz is developed. The design is successfully realized in theory and verified by full-wave electromagnetic simulation and the experiment, where excellent agreement is obtained.
| Original language | English |
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| Pages (from-to) | 2562-2568 |
| Journal | IEEE Transactions on Microwave Theory and Techniques |
| Volume | 55 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2007 |