Design, Fabrication and Characterization of a Microwave Resonator ...

6.1 Simulations in SonnetFigure 6.4: Simulation of the resonator R24 (a) Current distribution at the resonance at6.485 GHz, (b) Backward transmission S 12 and reflection S 11 .In this design the undercoupled resonators are analyzed with a meshing resolution sufficientto resolve the structures of the coupling capacitances. Figure 6.4(a) shows the currentdistribution of the resonator R24 at its resonance frequency. In Figure 6.4(b) one can easilyidentify the ground plane resonance at 5.42 GHz and the resonance frequency of 6.485 GHz.A summary of all measured resonators of design 1 is given in Table 6.2. R24 and R25 aredesigned for 5.85 GHz, R26 and R27 for 6.00 GHz. Even numbers are undercoupled, oddnumbers are overcoupled. The software was not able to simulate the overcoupled resonatorscontaining thin fingers, because of memory problems.resonator nc resonance (GHz) sc resonance (GHz)R24 6.54 6.485R25shortR26 6.675 6.615R27shortTable 6.2: Simulation results of design 1.6.1.1.3 Design 2The fabricated and measured resonator R36 has a medium coupling and was designed usingdesign 2. Besides this resonator four other resonators with design 2, shown in Table 6.3,were simulated. These resonators have linear scaled coupling capacitors compared to theYale design and design 1 (see also section 3.2).R28 and R30 are undercoupled, R29 and R31 are overcoupled resonators with 6 fingers(instead of 2 and 3 at Yale and design 1, respectively). All structures have a ground planemode at 5.4 GHz.63