# Specific Resonant Properties of Non-Symmetrical Microwave Antennas
## 4 Conclusions  
The original intention of our research was in the field of aircraft tail antennas. It was based on the analysis of the influence of an aircraft antenna's position on its directional properties. We expected standard outputs corresponding to the conventional knowledge of antenna theory, which is based on cylindrical antennas. By summarizing the measured results, we discovered some interesting properties of aircraft tail antennas modelled as flat microwave dipoles. This is due to the fact that flat microwave antennas behave differently in the region of resonant frequencies than generally expected.  
We presented this difference by comparing the resonant properties of cylindrical and flat antennas. The outputs from the measurement of tail antennas as flat microwave dipoles showed that the graphs of their resonance dependence on length intersect at one point. This fact was subjected to a theoretical analysis on the generally known course of the dependence of the antenna impedance on its ratio \(l/\lambda\). However, it was based only on the measured so-called antenna resonance points, i.e., when the reactance value of the antenna is equal to zero. It was the analysis of these points that showed that this is a new hitherto unknown view of a certain area of antenna theory applicable to modern, non-cylindrical antenna designs.  
Further measurements (which are not part of this article due to space limitations) have shown that the position of the significant crossover point changes depending on the thickness of the flat dipole and is lost with a cylindrical shape of the dipole. In addition, it was found that a significant point is also formed on the microwave antennas at a second, parallel, half-wave resonance, and for dipoles with capacitive load. As follows from the presented facts, new possibilities have opened up in the design and use not only of aircraft tail antennas but also of other kinds of flat microwave antennas, such as those in automobiles and UAVs.  
Figure 13: Concentrated distribution of the position of resonant points of a set of flat microwave antennas again showing the significant crossover point \(S\).  
**Author Contributions:** Conceptualization, J.L. and P.K.; methodology, J.L., P.K., and M.C.; software, M.C. and M.G.; validation, J.L., P.K., M.C., A.N., and C.F.; formal analysis, M.C., and A.N.; investigation, J.L., P.K., M.C., A.N., and C.F.; resources, P.K., and M.G.; data curation, M.C., and M.G.; writing--original draft preparation, J.L., P.K., M.C., M.G., A.N., and C.F.; writing--review and editing, J.L., P.K., M.C., M.G., A.N., and C.F.; visualization, M.C., and M.G.; supervision, J.L., and P.K.; project administration, P.K. and M.G.; funding acquisition, P.K., M.G., and A.N. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The work of Slovak authors [PERSON] and [PERSON] was supported by the Scientific Grant Agency (VEGA) under Contract 1/0584/20. The work of Slovak author [PERSON] was supported by the Slovak Research and Development Agency under Contract APVV-18-0373. The work of Russian author [PERSON] and Australian author [PERSON] was supported by the Southern Federal University.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Data sharing not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data in the writing of the manuscript, or in the decision to publish the results.