Gain improved stacked antenna tuned using ferromagnetic nanoparticles and ferroelectrics films

High gain tunable annular ring antenna structure for WiFi band are reported by stacking passive elements over an active element realized on a composite substrate of ferromagnetic nanoparticles or ferroelectric thin films with FR4 baseline substrate. Low coercivity material with high refraction index, low loss, and high saturation moment are attractive in realization of tunable small sized radio frequency (RF) circuits. The FeCo was characterized to have permeability of more than 8 and loss tangent of less than 0.1, while the BST have permittivity of more than 140 and loss tangent of less than 0.02. This paper addresses the use of Fe
₆₀
Co
₄₀
soft magnetic nanoparticles to realize high gain tunable stacked antennas for WiFi band and a similar approach is extended to manganese-doped Ba
_0.8
Sr
_0.2
TiO
₃
(BST) soft ferroelectric thin films. A Finite Element Method (FEM) computational method is used for design and performance optimization of composite antennas with superstrates to achieve frequency tuning and an improved gain. The designed FeCo antenna demonstrates 5% frequency tuning per 0.1T of applied DC magnetic field and realized gain of 3dBi. The simulated performance of BST based antenna is a frequency tuning of 1.6% and expected gain of 5dBi using a 40kV/mm electric field.