Low κ Mg2SiO4 ceramic tapes and their role as screen printed microstrip patch antenna substrates

Abstract

Despite their intolerance to fine machining, certain ceramics possess a unique combination of low dielectric constant and ultra-low dielectric loss, which is ideal for fabricating a patch antenna on them, with increased efficiency. In a candid attempt, we have qualified an ultra-low loss ceramic, magnesium silicate (abbreviated as Mg2SiO4), for microwave antenna applications. Flexible ceramic tapes are prepared through organic solvent-based tape casting method, stalked, isostatically pressed, sintered, and polished. The new substrate possesses excellent microwave dielectric properties on par with commercial polymer composite wafers, while thermal conductivity is two orders better than them. The feasibility of using Mg2SiO4 as microwave substrate was demonstrated by fabricating a microstrip patch antenna for WLAN applications. The radiation characteristics of the antenna show excellent agreement with the simulated ones. The patch antenna fabricated on Mg2SiO4 substrate radiated at 2.44 GHz with a gain of 3.2 dB and a return loss of −20 dB.