Synthesis and characterization of zinc substituted nickel ferrite materials for L band antenna applications

The synthesis of Ni 1−x Zn x Fe 2 O 4 (x = 0, 0.2 and 0.4) and its applicability to L band microwave antenna applications have been reported. The structural studies of the samples show a transformation from inverse to normal spinel structure with Zinc substitution. The Zn doping increases the ferromagnetic resonance of the material resulting in permeability values greater than one at GHz frequencies. It is observed that the Zn substitution of 0.2 has maintained the real part of permeability value constantly around 2.0 over the entire L band frequencies from 1 to 2.0 GHz with minimal losses. The synthesized Ni 0.8 Zn 0.2 Fe 2 O 4 material realized in the form of a superstrate coating of thickness 100 µm over a microstrip patch antenna has shifted the resonance frequency of the antenna to lower side by 45 MHz resulting in miniaturization with a good gain and efficiency.