Development of voltage tunable ferroelectric coplanar phase shifters for low cost high performance phased array antennas with beam steering capabilities

Abstract

In this paper we developed a ferroelectric CPW phase shifters which will be integrated with wideband CTS antenna array. For fabrication of the ferroelectric CPW, the vacuum sputter has been used with a optimized sputtering parameters. The experimental RF performances of the developed phase shifters were compared with those from simulations using WIPL-D software. The results showed that while the approach of using thin Ferroelectric films may be successful in designing low cost tunable coplanar waveguide phase shifters, the amount of achievable phase shifts are small (less that 10°) unless Ferroelectric compatable substrates such as STO are used (phase shifts are 27°). Good agreement was also observed between simulations and measured results and this provides high confidence in the developed fabrication process‥ While our group has been successful in fabricating thin film ferroelectric phase shifter, work is still underway to help develop multilayer ferroelectric phase shifters as well as on the development of an integrated CTS and ferroelectric phased antenna array. As a next step, our group is now pursuing fabrication of a ferroelectric multilayer CPW integrated with the CTS antenna array.