RF-MEMS Monolithic K and Ka Band Multi-State Phase Shifters as Building Blocks for 5G and Internet of Things (IoT) Applications

RF-MEMS, i.e., Micro-Electro-Mechanical Systems (MEMS) for Radio Frequency (RF) passive components, exhibit interesting characteristics for the upcoming 5G and Internet of Things (IoT) scenarios, in which reconfigurable broadband and frequency-agile devices, like high-order switching units, tunable filters, multi-state attenuators, and phase shifters will be necessary to enable mm-Wave services, small cells, and advanced beamforming. In particular, satellite communication systems providing high-speed Internet connectivity utilize the K and Ka bands, which offer larger bandwidth compared to lower frequencies. This paper focuses on two design concepts of multi-state phase shifter designed and manufactured in RF-MEMS technology. The networks feature 4 switchable stages (16 states) and are developed for the K and Ka bands. The proposed phase shifters are realized in a surface micromachining RF-MEMS technology and the experimentally measured parameters are compared with Finite Element Method (FEM) multi-physical electromechanical and RF simulations. The simulated phase shifts at both the operating bands fit well the measured value, despite the measured losses (S21) are larger than 5-7 dB if compared to simulations. However, such a non-ideality has a technological motivation that is explained in the paper and that will be fixed in the manufacturing of future devices.