Compact quasi‐Yagi antenna with enhanced bandwidth and stable high gain

A compact double‐dipole driver is constructed for designing quasi‐Yagi antenna with enhanced bandwidth and stable high gain. It is composed of a magnetic dipole and a folded electric dipole, realised by cylinder dielectric resonator and split‐ring resonator. The two dipoles operate at two close frequencies, leading to bandwidth enhancement. Meanwhile, the gains of the two dipoles are also close so that the stable gain in the operating band is obtained, which can be entirely enhanced by the zero‐index metamaterial in front of the dual‐dipole driver. For demonstration, an antenna prototype centred at about 9.6 GHz is implemented and measured. The simulated and measured results are given, showing good agreement.