RF-MEMS Modules with Amplitude and Phase Control for Beamforming Applications in 5G/6G Small Cells

The tremendous data rates of the current and future telecommunication standards rely on access points operating in the millimeter-wave (mmWave) bands and characterized by antenna array architectures. The expected proliferation of small cells (SC) comes with an increasing concern regarding the power consumption of such widespread nodes, which renovates the interest in the solutions based on passive electronics for the realization of the beamforming (BF) architecture. Within this context, the low-power consumption, together with the remarkable and wideband electrical features of Radio Frequency Micro Electro-Mechanical Systems (RF-MEMS), represents an advisable solution for the realization of the future reconfigurable BF networks. Such potential is demonstrated in this paper by a general-purpose and monolithic module, comprising a 3-bit attenuator, three phase-shifting cells, and a switch, with an overall footprint of 3.36 × 9.51 mm2. The low driving voltage of such network is ensured by the adoption of movable membranes with an actuation voltage of 7 V. The preliminary simulations displayed wideband isolation features (− 25 dB up to − 27.22 GHz), together with an amplitude control ranging from − 5.39 to − 13.51 dB and a phase control covering the 14.03°–158.46° interval at the center frequency (25.87 GHz) of the considered spectrum.