A shielded planar dielectric resonator with whispering gallery modes

The spectral and energy characteristics of two planar dielectric resonators (DRs), open and shielded from the curvilinear surface, excited in higher-order modes as whispering gallery modes (WGMs) in Ka-waveband are investigated. These resonators are formed by a thin (compared to the operating wavelength) disk dielectric structure, located between two conducting planes. Thus, the E-field of the resonator was limited along the height of the planar disk by two conducting surfaces. The resonance properties of such a structure are determined by the condition of total internal reflection of waves from the internal curvilinear surface of a dielectric disk. The carried out investigations shown that the unloaded Q-factor is increased at the arrangement of planar dielectric disk inside the ring metal shield at the certain ratio of the radiuses of the shield and dielectric disk. The Q-factor of the shielded resonant structure at the high-frequency edge increases to 40 %. The partial displacement of the resonant field of the WGMs modes from the dielectric to the air gap is the cause of this effect. It leads to decrease in losses in the dielectric material. A computer simulation of the WGMs fields in the planar DR was carried out using the CST Microwave Studio 2013 software to confirm this effect. In addition, computer simulation results shown that these WGMs in the planar DR are characterized by a homogeneous distribution of the resonant field along the axial coordinate. The perspectives of using planar DR in solid-state Ka-band oscillators are shown.

1. Il’chenko M. E., Vzyatyshev V. F., Gassanov L. G. et.al. Dielectric Resonators. Moscow, Radio i sviaz’ Publ., 1989. 328 p. (in Russian).

2. Kirichenko A. Ia., Prokopenko Iu. V., Filippov Iu. F., Cherpak N. T. Quasi-Optical Solid-State Resonators. Kiev, Naukova dumka Publ., 2008. 296 p. (in Russian).

3. Golubnichaya G. V., Kirichenko A. Ya., Krivenko E. V., Lutsenko V. I. The effect of gap width between disks on the Q value of a laminar dielectric disk resonator. Technical Physics Letters, 2015, vol. 41, no. 3, pp. 281–283. https://doi.org/10.1134/ s1063785015030207

4. Yurchenko V., Altintas A., Ciydem M., Koc S. Experimental conditions for the excitation of thin disk whispering gallery-mode resonators. Progress in Electromagnetics Research C, 2013, vol. 43, pp. 29–40. https://doi.org/10.2528/pierc 13062803

5. Annino G., Cassettari M., Martinelli M. Study on planar whispering gallery dielectric resonators. I. General properties. International Journal of Infrared and Millimeter Waves, 2002, vol. 23, no. 4, pp. 597–615. https://doi.org/10.1023/a: 1015709927809

6. Kogut A. E., Dolya R .S., Nosatiuk S. O., Shulha Ye. A., He Zhaochan. Excitation of whispering gallery vibrations in a disk planar dielectric resonator by the coupling gap. Vestsi Natsyyanal’nai akademii navuk Belarusi. Seryya fizika-technichnych navuk = Proceedings of the National Academy of Sciences of Belarus. Physical-technical series, 2017, no. 3, pp. 121–128 (in Russian).

7. Santhosh Kumar G. D. V., James Raju K. C. Whispering Gallery Modes of Planar Dielectric Resonators in LTCC Technology. Emerging Research Areas and 2013 International Conference on Microelectronics, Communications and Renewable Energy (AICERA/ICMiCR), 2013 Annual International Conference on, pp. 474–479. https://doi.org/10.1109/ aicera-icmicr.2013.6576026

8. Hiratsuka T., Sonoda T., Sakamoto K., Ishikawa Y. K-band planar type dielectric resonator filter with high-/spl epsiv/ ceramic substrates. IEEE MTT-S International Microwave Symposium Digest, 1998, vol. 3, pp. 1311–1314. https://doi. org/10.1109/MWSYM.1998.700615

9. Eremenko Z. E., Filipov Y. F., Kharkovsky S. N., Kutuzov V. V., Kogut A. E. Whispering-Gallery Modes in Shielded Hemispherical Dielectric Resonators. IEEE Transactions on Microwave Theory and Techniques, 2002, vol. 50, no. 11, pp. 2647–2649. https://doi.org/10.1109/TMTT.2002.804627

10. Ivanov E. N., Karachev A. A., Tsarapkin D. P. Increasing the excitation efficiency of disk dielectric resonators. Izvestiia vuzov. Radioelektronika = Radioelectronics and Communications Systems, 1987, vol. 30, no. 10, pp. 68–69 (in Russian).

11. Ginzton E. L. Microwave Measurements. New York, McGraw-Hill, 1957. 519 p.