Fig. 6
Antenna radiation patterns. a Antenna with \(44^{\circ }\) HPBW in both V and H-plane, b antenna with \(29^{\circ }\) HPBW in both V and H-plane, c antenna with \(16.5^{\circ }\) HPBW in both V and H-plane and d antenna with \(10^{\circ }\) HPBW in both V and H-plane