 filters are effective, the piezo layer must be only micro-meters thick, requir- ing the resonator structure to be made using thin-film deposition and micro-machining on a carrier substrate. The BAW filter size also decreases with higher frequencies, which makes ideal for most wireless applica- tions. In addition, BAW design is far less sensitive to temperature variation even at broad bandwidths. MEMS are millimeter/sub-millimeter devices, realizing a certain transduction function between two (or more) distinct physical domains, among which the mechanical is always involved. More specifically, regard- less of the specific function it is conceived for, a MEMS device always features tiny structural parts that move, bend, stretch, deform, and/or contact together. These characteristics make micro-system devices par- ticularly suitable for the realization of a wide variety of micro-sized sensors and actuators. New Radio Access RF and Transceiver Design Considerations 737 its cost of production. However, with the recent improvement of the process, GaAs pHEMT has become the mainstream for the development of LNAs. For cost and performance con- siderations, the mainstream process is the gate length of 0.25 um. GaAs pHEMT technology allows implementation of gate lengths in the order of 0.1 um. As an example, the NF and gain of a prototype LNA based on the latter technology is 1.3 and 7 dB, respectively, at 40 GHz. Another prototype LNA developed by one of the leading RF companies has 0.13 um gate length and a cutoff frequency of 110 GHz with an NF of less than 0.5 dB in 8-12 GHz band [26]. Switches are the smallest active electronic components and play a critical role in the overall operation and performance of wireless communication systems. Switches route the transmit and receive signals at different frequencies, enable monitoring and calibration, and are the baseline component for functions such as phase shifting and step attenuation. The 5G wire- less systems will continue reliance on solid-state switching. The switch 