Synthesis and fabrication of GPS patch antennas by using Zn(1 − x)Ti x Al2O4 thin films

Abstract

Zn(1 − x)Ti x Al2O4-based microwave dielectric ceramics were prepared by sol–gel method. The obtained compounds were characterized and fabricated as GPS patch antennas. The XRD patterns show a three-phase system with a spinel ZnAl2O4, anatase and a rutile (TiO2). The addition of TiO2 increased the crystallite size and grain size, and surface morphology tended to increase the ceramics density (4.61–4.75 g/cm3) and dielectric constant, e r (8.56–13.51). Based on the material investigated and microwave antenna theory, GPS patch antennas were fabricated using Zn(1 − x)Ti x Al2O4 and then measured using a PNA series network analyzer. The surface of the GPS patch antennas and ground plane was coated with 200-nm-thick silver to enhance ohmic contact. The patch antenna sizes decreased as e r increased from 2.88 × 4.37 cm (12.58 cm2) to 3.53 × 2.21 cm (7.80 cm2). Among these antennas, the Zn0.70Ti0.30Al2O4 shows an excellent performance combination between return loss (−28.71 dB), small size (3.53 × 2.21 cm), and wide bandwidth (270 MHz).