*4.6.2 H-plane*

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)** and **(b)**, respectively.
