RF-MEMS and SiC/GaN as enabling technologies for a reconfigurable multi-band/multi-standard radio

Abstract

With more and more air interfaces introduced into the wireless market, the product spectrum of different base stations by a worldwide-engaged infrastructure vendor becomes increasingly diverse. Therefore, it is desirable to shrink the product spectrum while still matching the different market needs. This paper presents key enabling technologies, such as radio frequency-microelectromechanical system (RF-MEMS) and silicon carbide/gallium nitride (SiC/GaN) transistors, which allow for a base station radio architecture that can be reconfigured. The paper first analyses the market scenario and compares the principles of a reconfigurable radio with classical software radio technology. Direct-mixing transceiver architecture is proposed for implementation, and solutions for multi-band capability are discussed. RF-MEMS devices are used to switch filters, tune capacitances and inductances, and specifically adapt impedance matching. For multi-band power amplifiers, the benefit of operating a SiC or GaN radio frequency (RF) power device at high voltage is addressed. All these technologies lead to an analog software radio (also called frequency agile radio) where it will turn out that such a radio can be realized at less complexity and cost compared to a classical digital software radio. Furthermore, it will show up that analog software radio technology based on RF-MEMS also has the potential to enter the terminal market.