**4.2 Return loss**

The obtained return loss simulation results for the single cavity Vivaldi antenna and double cavity Vivaldi antenna are as shown in **Figure 9(a)** and **(b)**, respectively.

**141**

**Figure 7.**

*Characterization of Printed Podal Vivaldi Antenna (8–18 GHz) on RT Duroid with Single…*

Usually the return loss is the loss of power in the signal that is returned/reflected by a discontinuity in a transmission line. A minor discontinuity can be observed with the

*(a) Simulated VSWR for single cavity Vivaldi antenna without SMA connector and (b) simulated VSWR for* 

Practically, VSWR for the desired band of frequencies is measured using a network analyzer. The VSWR of the proposed antenna was measured using Agilent ENA series Vector Network Analyzer (VNA) E5071C and was found to be less than

The measured VSWR for single cavity antenna and double cavity Vivaldi

This discontinuity can be a mismatch with the terminating load or with a device inserted in the line. It is usually expressed as a ratio in decibels (dB).

terminating load or with a device inserted in the line.

antenna are shown in **Figure 10(a)** and **(b)**, respectively.

3:1 throughout the desired frequency band.

*double cavity Vivaldi antenna without SMA connector.*

**4.3 Return loss measurement**

*DOI: http://dx.doi.org/10.5772/intechopen.88727*

*Characterization of Printed Podal Vivaldi Antenna (8–18 GHz) on RT Duroid with Single… DOI: http://dx.doi.org/10.5772/intechopen.88727*

**Figure 7.** *(a) Simulated VSWR for single cavity Vivaldi antenna without SMA connector and (b) simulated VSWR for double cavity Vivaldi antenna without SMA connector.*

Usually the return loss is the loss of power in the signal that is returned/reflected by a discontinuity in a transmission line. A minor discontinuity can be observed with the terminating load or with a device inserted in the line.

Practically, VSWR for the desired band of frequencies is measured using a network analyzer. The VSWR of the proposed antenna was measured using Agilent ENA series Vector Network Analyzer (VNA) E5071C and was found to be less than 3:1 throughout the desired frequency band.

The measured VSWR for single cavity antenna and double cavity Vivaldi antenna are shown in **Figure 10(a)** and **(b)**, respectively.
