![]() ![]() This effect makes these switches impractical for wireless communication applications. ![]() Many meandering topologies have been reported and they are typically lowering the pull-in voltage but exhibits low RF performance due to inductance developed between meanders and ground plane. ![]() proposed three different types of switches having length 300 µm and width 100 µm and achieved the operating voltage of 4.8–6.2 V. proposed a rotated spring structure and reduces the pull-in voltage to 7.75 V. proposed two folded meander structure at 4 µm to suspend the central beam which offers low spring constant to reduce the actuation voltage up to 9.7 V. proposed a novel arrangement of uniform meanders and achieved an actuation voltage of 18.3 V. Nowadays, an intensive research is going on to develop a low pull-in voltage and high isolation of RF MEMS switches. The use of high dielectric materials to increase down state capacitance which produces high isolation and that avoids leakage currents. The isolation of the RF switch is also a major another issue to avoid leakage currents. Reducing pull-in voltage is a great challenge in RF MEMS switches and a large number of structures have been developed to overcome the issues. Among them electrostatic actuation is suitable to integrate wireless devices due to low power consumption in few milliwatts, low switching time ranges from 10 to 100 µs and large capacitance ratio but these switches requires high pull-in voltage from 5 to 100 V. The mechanical movement is achieved by different mechanisms such as electrostatic, electromagnetic and thermal. The working of RF switch comprises of both electrical and mechanical actuation. These switches are classified as shunt and series type based on its configuration with transmission lines. The need of RF MEMS switches is increasing day by day because of increasing low power wireless applications. RF MEMS switches can be efficiently deployable in the networks and antenna systems due to better reliable characteristics than conventional switches (PIN diodes, FETs and transistors) at microwave applications. These switches are utilised as a major device for switching between RF splitters and transmitter/receivers in the satellite uplink and downlink networks (Fig. Among them RF MEMS switches are efficiently used in radar and satellite communication due to its low cost, low power dissipation and high reliability apart from reduced size and mass. The emergence of technology has brought wide attention to develop RF devices such as switches, switched capacitors, resonators, tunable inductors, varactors and filters. The inter-disciplinary nature of micro-electromechanical system (MEMS) technology and miniaturisation of the devices made them more reliable for wide range of satellite, defence, mobile and broadcasting, consumer electronics, automotive, medical, RADAR and communication applications. Recent advancement in technology strives to deploy pico and nano-satellites weighing a few tens of kilograms into the space. The upstate capacitance of 56.8 pF contributes low return loss and made the switch to transmit the signal up to 26.2 GHz and provides 7.2 pF of downstate capacitance to produce high isolation at 26.2 GHz which is efficiently used for K-band satellite applications. The switch also shows good quality factor of 0.95 for gold material along with high capacitance ratio of 132. The analysis has been carried out for different beam and dielectric materials among them switch with gold material exhibits low pull-in voltage of 4.7 V, low insertion loss <1 dB and high isolation of −38.3 dB at 28.2 GHz for silicon nitride. Stress analysis, electromechancial, switching time, quality factor and RF analysis have done to understand the behavioural characteristics of the proposed step-down switch. The central beam of the membrane is designed with 0.5 µm lower than the side beams to form a step-down structure which reduces the pull-in voltage. This study reports the design and analysis of novel step structure RF micro-electromechanical system (MEMS) switch for low pull-in voltage, low insertion loss and high isolation by using uniform single meander. IET Generation, Transmission & Distribution.IET Electrical Systems in Transportation.IET Cyber-Physical Systems: Theory & Applications.IET Collaborative Intelligent Manufacturing.CAAI Transactions on Intelligence Technology.
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