A fundamental limit on the performance of geometrically-tuned planar resonators


Naji, A., Warr, P., Beach, M. and Morris, K., 2011. A fundamental limit on the performance of geometrically-tuned planar resonators. IEEE Transactions on Microwave Theory and Techniques, 59 (6), pp. 1491-1499.

Related documents:

This repository does not currently have the full-text of this item.
You may be able to access a copy if URLs are provided below. (Contact Author)

Official URL:

Related URLs:


Geometric frequency tuning in planar electromagnetic resonators is common in many applications. It comes, however, at a penalty in the resonance quality, Q(0). The literature traces the causes of such penalty often in terms of the shortcomings in the added elements and materials, which were used to achieve the tuning. In this paper, however, it is shown that another underlying source of quality degradation exists at the fundamental geometric level. This source, unlike other added sources of degradation during tuning, will always exist (even before tuning takes place) and will rely on the "modal areas" of the geometric modifications made to host the tuning mechanism. Hence, it forms an upper bound to the performance that can be achieved from a geometically-tuned planar resonator, carries an important insight to resonator design in general, and significantly helps in the understanding of the problem of geometric tuning in particular. We present the electromagnetic theory behind this limit and canonically demonstrate it using practical microwave resonator examples. The theory, finite-element method simulation, and experiment results are presented and good agreement is observed. It is shown that incorporating such understanding into the design process of tunable planar resonators can help optimize their performance against a given set of design requirements. Furthermore, the presented theory provides a useful electromagnetic model as a tool for estimating Q(0) for geometrically modified or irregular metal patches and planar resonators in general, to assist analysis, and design at any wavelength or application. The theory also asserts that, under a given mode, a planar resonator will always have its maximum Q(0) before introducing any internal subtractive geometric modifications (e. g., cuts, apertures, or slits) to its original shape.


Item Type Articles
CreatorsNaji, A., Warr, P., Beach, M. and Morris, K.
Related URLs
Uncontrolled Keywordsunloaded q,tunable resonators,design optimization,frequency tuning,applied electromagnetism,planar resonator,microstrip resonator,tunable filters,millimeter resonators
DepartmentsFaculty of Engineering & Design > Electronic & Electrical Engineering
ID Code24761


Actions (login required)

View Item