Abstract
This paper presents a new bandwidth tuning theory for Butterworth-response resonator filters. The presented theory shows that the bandwidth of odd-order Butterworth filters can be varied by adjusting only two interresonator coupling structures while maintaining a perfect impedance matching at the center frequency. In other words, this paper presents an analytic approach to reduce the number of tunable coupling structures when designing a bandwidth-tunable resonator filter. Theories for third- A nd fifth-order direct-coupled filters are discussed in detail, and it is shown that only two interresonator coupling structures are required to be tunable. In addition, for verifying the new bandwidth tuning method, a fifth-order cylindrical cavity filter has been designed, fabricated, and measured. The fabricated filter has an 11:1 bandwidth tuning range.
| Original language | English |
|---|---|
| Article number | 8653495 |
| Pages (from-to) | 1496-1503 |
| Number of pages | 8 |
| Journal | IEEE Transactions on Microwave Theory and Techniques |
| Volume | 67 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2019 Apr 1 |
Keywords
- Bandwidth tuning
- cavity resonator
- interresonator coupling
- topology
ASJC Scopus subject areas
- Radiation
- Condensed Matter Physics
- Electrical and Electronic Engineering