VARACTOR-TUNED FILTERS AT MICROWAVE FREQUENCIES.
Abstract
The unloaded Q of a varactor-tuned cavity is derived from a solution of Maxwell's equation. The derivation takes into account the Q multiplying properties of a length of transmission line loaded with a varactor. An equation is written which relates the tuning range of a cavity length for a given ratio of maximum to minimum varactor capacitance. The equation was solved on a computer and the results are given in graphical form. Using the general Q equation, a plot is made of Q multiplication factor as a function of cavity length. These results, in graphical form, can be used to determine the maximum unloaded Q obtainable over a given tuning range for a varactor of known cut-off frequency and capacitance. Two types of varactor-tuned TEM cavities are discussed and design procedures given. Methods of controlling bandwidth over a tuning range are discussed for both bandpass and bandstop filters. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 1965
- Accession Number
- AD0629631
Entities
People
- Roger L. Fjerstad
Organizations
- Sylvania Electric Products