**4.7 Gain of the antenna**

The method used for the gain measurement of the antenna is gain-transfer method. In this technique the standard gain antenna which is known is used to determine the test antenna. Initially relative gain measurements are performed, which when compared with the known gain of the standard antenna gives the

**Figure 15.** *(a) H plane patterns for single cavity Vivaldi antenna and (b) H plane patterns for double cavity Vivaldi antenna.*

**147**

**Figure 16.**

*antenna.*

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

For measuring the gain of the antenna under test (AUT), formula is

Gain of AUT (dB) = antenna power (dB) – reference antenna power (dB)

The measured gain plots of single cavity Vivaldi antenna and double cavity

Finally, single cavity Vivaldi antenna gives the efficient impedance bandwidth

*(a) Simulated gain plot of single cavity Vivaldi antenna and (b) simulated gain plot of double cavity Vivaldi* 

Vivaldi antenna are shown in **Figure 17(a)** and **(b)**, respectively.

+ gain (reference antenna) (2)

absolute values. The simulated gain of single cavity Vivaldi antenna varies from 3.36 to 8.55 dBi over the design frequency band as shown in **Figure 16(a)**. The simulated gain of double cavity Vivaldi antenna varies from 2.62 to 8.65 dBi over the design

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

frequency band as shown in **Figure 16(b)**.

than the double cavity Vivaldi antenna.

given by

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

absolute values. The simulated gain of single cavity Vivaldi antenna varies from 3.36 to 8.55 dBi over the design frequency band as shown in **Figure 16(a)**. The simulated gain of double cavity Vivaldi antenna varies from 2.62 to 8.65 dBi over the design frequency band as shown in **Figure 16(b)**.

For measuring the gain of the antenna under test (AUT), formula is given by

Gain of AUT (dB) = antenna power (dB) – reference antenna power (dB) + gain (reference antenna) (2)

The measured gain plots of single cavity Vivaldi antenna and double cavity Vivaldi antenna are shown in **Figure 17(a)** and **(b)**, respectively.

Finally, single cavity Vivaldi antenna gives the efficient impedance bandwidth than the double cavity Vivaldi antenna.

**Figure 16.** *(a) Simulated gain plot of single cavity Vivaldi antenna and (b) simulated gain plot of double cavity Vivaldi antenna.*

*Advances in Array Optimization*

and **(b)**, respectively.

and **(b)**, respectively.

**4.7 Gain of the antenna**

*4.6.2 H-plane*

wave. The E-plane (XY-plane at θ = 90°) radiation patterns at different frequencies from 8 to 18 GHz for single cavity and double cavity are as shown in **Figure 14(a)**

The plane containing the magnetic field vector is referred as the H aperture and the direction of maximum radiation. The "H" plane lies at a right angle to the "E" plane. The H-plane (ZX-plane at ф = 0°) radiation patterns at different frequencies from 8 to 18 GHz for single cavity and double cavity are as shown in **Figure 15(a)**

The method used for the gain measurement of the antenna is gain-transfer method. In this technique the standard gain antenna which is known is used to determine the test antenna. Initially relative gain measurements are performed, which when compared with the known gain of the standard antenna gives the

*(a) H plane patterns for single cavity Vivaldi antenna and (b) H plane patterns for double cavity Vivaldi* 

**146**

**Figure 15.**

*antenna.*

**Figure 17.** *(a) Measured gain plot of single cavity Vivaldi antenna and (b) measured gain plot of double cavity Vivaldi antenna.*
