# Method of Measuring Effective Dielectric Permittivity of Partially Filled Waveguides Using a Mismatched T-Bridge

## DOI:

https://doi.org/10.20535/RADAP.2019.78.6-12## Keywords:

effective dielectric permittivity, partial dielectric filling, method for measuring effective dielectric permittivity, partially filled waveguide, teaching and learning activities## Abstract

**Introduction**. Waveguides, partially filled with dielectric material (partially filled waveguides) are widely used in the super high frequency equipment. They have certain advantages over hollow waveguides, including the possibility of reducing sizes of a cross-section, increasing the power of radiation and suppressing undesired types of waves. Following the production of diverse new dielectric materials intended for use in super high frequency range devices, there is a need to continuously develop methods of calculation and measuring characteristics of partially filled waveguides.**Statement of the problem**. The theory of completely filled waveguides and waveguides with dielectric filling along narrow walls is developed quite thoroughly. However, its application to various waveguide devices requires the solution of transcendental equations, which is possible only using numerical methods. This makes it difficult to obtain information about any characteristics of a device. There is also an effect of a large number of factors influencing the characteristics of partially filled waveguides (degree of filling, position of a waveguide plate, magnitude of the dielectric permittivity, etc.). For the study of partially filled waveguides with different sample height, among others, this paper presents an approach, which is based on the representation of the relative permittivity of the medium in the form of two real functions, each of which depends on the cross-section from one coordinate. This is an approximate method for determining the proper scalar and vector functions of partially filled waveguides. The solution of the electrodynamic problem for partially filled waveguides is reduced to determining the propagation constant in a waveguide using exact or approximate methods. This paper presents the method which allows calculating the propagation constant at any frequency, by measuring the value of effective dielectric permittivity.**Results and discussion**. According to the results of the analysis, it is shown that known methods of measuring effective dielectric permittivity (using a measuring line, a panoramic indicator, and a bridge meter) have certain shortcomings in relation to the modification of partially filled waveguides, bandlimitedness, and a significant relative error of measurement with increasing effective dielectric permittivity. In particular, the lack of bridge meters is a very narrow frequency range in which the bridge remains matched. It is almost necessary to match the bridge at each frequency, reaching the absence of a signal in the arm E for identical loads that are connected to the side arm. For this, bridges have tuning elements in the form of pins, diaphragms, etc. The method for measuring effective dielectric permittivity of partially filled waveguides using an unmatched T-bridge, which does not have these deficiencies, is introduced.**Conclusions**. The scientific novelty of the proposed method for measuring effective permittivity of partially filled waveguides using an unmatched T-bridge is the possibility of providing broadbandness, increasing the accuracy of measurements, and the universality through the use of a panoramic indicator of the standing wave ratio using the voltage and electron-computer. One more point is the ability to measure effective dielectric permittivity when other measurement methods are not suitable. The results obtained should be used when designing new antenna systems, which include partly filled waveguides, as well as part of teaching and learning activities for creating new workplaces or improving existing ones aimed at laboratory and practical training using the above method of measurement.

## References

Chernishov P., Samsonov V.P. and Chernishov M.P. (2006) *Tekhnichna elektrodinamika* [Technical electrodynamics]. Kharkiv: NTU "KhPI", 290 p.

Kolomeytsev V.A., Komarov V.V. and Khomyakov S.V. (2000) Ridged waveguides with thin dielectric slabs. *Microwave and Optical Technology Letters*, Vol. 25, Iss. 6, pp. 419-423. DOI: 10.1002/(sici)1098-2760(20000620)25:6<419::aid-mop16>3.0.co;2-7

Ando M., Hirokawa J., Yamamoto T., Akiyama A., Kimura Y. and Goto N. (1998) Novel single-layer waveguides for high-efficiency millimeter-wave arrays. *IEEE Transactions on Microwave Theory and Techniques*, Vol. 46, Iss. 6, pp. 792-799. DOI: 10.1109/22.681202

Scott M.M. and Faircloth D.L. (2013) Microwave Permittivity Determination for Materials With Out-of-Plane and Off-Diagonal Dielectric Anisotropy. *IEEE Transactions on Microwave Theory and Techniques*, Vol. 61, Iss. 6, pp. 2471-2480. DOI: 10.1109/tmtt.2013.2260169

Wang W., Zhong S., Zhang Y. and Liang X. (2006) A Broadband Slotted Ridge Waveguide Antenna Array. *IEEE Transactions on Antennas and Propagation*, Vol. 54, Iss. 8, pp. 2416-2420. DOI: 10.1109/tap.2006.879216

Krenitsky A. P. and Meshchanov V. P. (2001) *Sverkhshirokopolosnyye mikrovolnovyye ustroystva* [Ultra-wideband microwave devices]. Moscow, Radio and Communications, 554 p.

Neganov V.A., Klyuev D.S. and Tabakov D.P. (2015) *Ustroystva SVCH i antenny* [Microwave devices and antennas]. Moscow, 724 p.

Somov A.M. and Kabetov R.V. (2016) *Proyektirovaniye antenno-fidernykh ustroystv* [Designing antenna-feeder devices]. Moscow, Hotline-Telecom, 282 p.

Kuraev A. A., Popkova T. L. and Sinitsyn A. K. (2004) *Electrodynamics and radio wave propagation* [Elektrodinamika i rasprostraneniye radiovoln], Minsk, Bestprint, 357 р.

Orfanidis S. J. (2008) *Electromagnetic Waves and Antennas* Textbook, Rutgers University, 819 p.

Karashchuk N. M., Manoylov V. P., Friez S. P. and Chukhov V. V. (2018) Investigation of the influence of partial dielectric filling on the dimensions of a rectangular waveguide [Doslidzhennya vplyvu chastkovoho dielektrychnoho zapovnennya na rozmiry pryamokutnoho khvylevodu], *Problems of creation, testing, application and operation of complex information systems}, Vol. 15, рр. 103-117.*

Pochernyaev V.N. and Tsibizov K.N. (2003) *Teoriya slozhnykh volnovodov* [The Theory of Complicated Waveguides] Kyiv: Naukoviy St. 224 p.

Abdullin R.R. and Sokolov R.I. (2016) Experimental research of leaky-wave antenna based on covered rectangular waveguide with transverse slots. *2016 URSI Asia-Pacific Radio Science Conference (URSI AP-RASC)*, . DOI: 10.1109/ursiap-rasc.2016.7601153

Pochernyaev V.N. and Skrypnik L.V. (1990) Eigenfunctions of a partially filled rectangular waveguide. *Radiophysics and Quantum Electronics*, Vol. 33, Iss. 12, pp. 1023-1028. DOI: 10.1007/bf01040145

Bovtun V., Kempa M., Kamba S., Pashkov V., Molchanov V., Poplavko Y. and Yakymenko Y. (2013) Microwave characterization of dielectric substrates for thin films deposition. *2013 IEEE XXXIII International Scientific Conference Electronics and Nanotechnology (ELNANO)*. DOI: 10.1109/elnano.2013.6552081

Koledintseva M.Y., Drewniak J.L. and Hinaga S. (2011) Effect of anisotropy on extracted dielectric properties of PCB laminate dielectrics. *2011 IEEE International Symposium on Electromagnetic Compatibility*. DOI: 10.1109/isemc.2011.6038366

Manoylov V. P. and Chuhov V. V. (2006) Calculation of the waveguied with the shape dielectric fulfills, *Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia*, Iss. 33, pp. 91-100. DOI: 10.20535/RADAP.2006.33.91-100

Chukhov V. (2004) Method of dielectric permeability type determination and its measurement. *The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828)*. DOI: 10.1109/msmw.2004.1346162

Sidorchuk O.L., Manoilov V.P. (2013) Method of measurement of EPR. *Microwave & Telecommunication Technology (CriMiCo-2013)*, pp. 546–547

Manoilov V. P. and Sydorchuk O. L. (2014) *Systema dlia nepriamoho vyznachennia antennoi skladovoi efektyvnoi poverkhni rozsiiuvannia aperturnykh anten* [The system for the indirect use of an antenna for warehouse warehousing of effective surface apertures]. Patent UA106557

## Downloads

## Published

## How to Cite

*Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia*, (78), pp. 6-12. doi: 10.20535/RADAP.2019.78.6-12.

## Issue

## Section

## License

Authors who publish with this journal agree to the following terms:

- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).