RF MEMS, BST, and GaAs varactor system-level response in complex modulation systems

This article presents the response of RF microelectromechanical systems (RF MEMS), barium strontium titanate (BST), and gallium arsenide (GaAs)-based tunable filters and reconfigurable matching networks to a wideband code-division-multiple-access signal centered at 1.95 GHz. The RF MEMS tunable filter and impedance tuner result in very low intermodulation distortion and spectral regrowth compared to their BST and GaAs counterparts. The linearity of the BST and GaAs tunable networks improves considerably by using a series combination of BST and GaAs varactors, but the RF MEMS-based networks still show the best linearity of all three technologies. Also, it is shown that the reconfigurable networks, tuned with capacitive RF MEMS can handle up to 1W of RF power with no self-actuation.