**Author details**

the transmitted signal can be inferred. For a given frequency, the average group delay represents the time required for a signal to travel from one antenna terminal

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

(i.e., far-field conditions) and aligned with the E-plane (**Figure 16**).

The group delay of both the SAVA and CAVA configurations was measured in a free space environment. A network analyzer was used to measure the S21 group delay between two identical antennas (in each configuration) placed 2.5 m apart

Clearly, the SAVA shows a smoother and more linear behavior, whereas the CAVA exhibits strong group delay variation, indicating phase nonlinearity along

This work has proposed a novel class of SAVAs. The geometry of the considered

radiating structures is optimized by means of the super-ellipse formula, thus achieving UWB operation. Compared with current conventional Vivaldi antenna configurations, the proposed topology yields compelling benefits in terms of better impedance-matching properties, larger efficiency, gain, and front-to-back radiation ratio across a broad frequency range, without compromising on antenna compactness. The high directional radiation characteristics of SAVAs make them suitable for several applications, such as UWB communications and remote sensing, microwave

imaging, ground penetrating radar, and biomedical screening.

to the other.

**Figure 16.**

**4. Conclusion**

**184**

most of the frequency band.

*Measured group delay of the SAVA and CAVA antennas.*

Abraham Loutridis<sup>1</sup> , Simay Kazıcı 2 , Oleg V. Stukach<sup>3</sup> , Arman B. Mirmanov4 and Diego Caratelli2,5\*

1 Alps Alpine Europe, Munich, Germany

2 The Antenna Company, Eindhoven, The Netherlands

3 Higher School of Economics (HSE), National Research University, Moscow, Russia

4 Seifullin Kazakh Agro Technical University, Astana, Kazakhstan

5 Eindhoven University of Technology, Eindhoven, The Netherlands

\*Address all correspondence to: diego.caratelli@antennacompany.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
