New design of high-Q sapphire resonator with distributed Bragg reflector

Invited Article: Dielectric material characterization techniques and designs of high-Q resonators for applications from micro to millimeter-waves frequencies applicable at room and cryogenic temperatures

“…(Left) Dielectric loaded cavity field density plot of a WGH or E-mode, and (right) dielectric loaded cavity density plot of a WGE or H-mode (left), as calculated using the Method of Lines. 46,54,55 We chose a high azimuthal mode number to confine all the energy into the crystal illustrated with a black contour. cavity walls affect the resonator properties (except for spurious modes).…”

“…Those parameters are calculated with rigorous electromagnetic simulation software, in our case it is based on the Method of Lines. 46,54,55 The formulas for both p e and G are given below in Eqs. (5) and (6) and their evolution with the azimuthal mode number in Figure 8:…”

“…Determination of the permittivity of the sample is achieved by retrosimulation using finite element analysis, mode matching, or in our case the Method of Lines (MoL). 46,54,55 MoL has been used to develop rigorous electromagnetic simulation software for the purpose of material characterization; therefore, the extraction of the filling factors, geometric factor, and complex permittivity determination is obtained automatically. The method can be used for isotropic and anisotropic material from a thickness of a few cm to a few mm.…”

“…Depending on the application, the requirement on material properties and size of the dielectric, the make-up of the resonator can vary substantially. To make the right choice of material and dimensions, it is very important to use precise experimental and numerical techniques [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] to properly characterize materials. In this paper, we present some important non-intrusive resonant techniques to characterize dielectric samples, which depend on the scale size of the sample.…”