Magneto-dielectric material characterization and antenna design for RF applications

Abstract

Antenna miniaturization without deteriorating performance is challenging because the performance is bounded by fundamental limits depending on the size of the antenna. Magneto-dielectric materials, however, have been reported as providing new possibilities for antenna miniaturization in many recent studies. In this paper, a novel material characterization method which is a cavity perturbation technique (CPT) with substrate integrated waveguide (SIW) cavity resonator is presented for extracting the properties of magneto-dielectric material. CPT formulas for extracting complex permittivity and complex permeability are explained and modification process using 3D EM simulation tool is discussed. Design and fabrication of SIW cavity resonators is presented. The frequency dependent properties of permittivity and permeability for synthesized magneto-dielectric material are extracted in the frequency range of 1-4 GHz. Microstrip patch antenna working at 1GHz on magneto-dielectric substrate has been designed and simulated in this paper.

Magneto-Dielectric Nanocomposite for Antenna Miniaturization and SAR Reduction

“…CPT is a well-known method for extracting the electromagnetic properties of various materials. Substrate integrated waveguide (SIW) was used to implement the cavity for CPT measurement, as described in detail in [10]. The real part of the relative permittivity is approximately εr' ≈ 8, which is fairly constant over the frequency range up to 4GHz.…”

“…Using high permittivity material for antenna substrate, however, suffers from narrow bandwidth and low efficiency [1]. On the other hand, magneto-dielectric (MD) materials which have relative permittivity and permeability greater than unity have been applied to reduce the antenna size and has shown to provide performance advantages [2]- [4].…”