# Comprehensive Review of RF MEMS Switches in Satellite Communications
## 3 Strategies for Optimizing RF MEMS Switch Performance
### High Reliability
#### 3.1.2 Reducing Actuation Voltage
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Actuation Mechanism** & **Acuation** & **Acuation** & **Insertion Loss** & **Isolation** & **Ref** \\ \hline Thermal/Electrostatic & Vertical & 0.3 V & 0.23 dB @ 2.4 GHz & 38.80 dB @ 2.4 GHz & [28] \\ Thermal/Electrostatic & Lateral & 7 V & \(-\)0.73 dB @ 6 GHz & \(-\)46 dB @ 6 GHz & [101] \\ Thermal/Electrostatic & Lateral & 6 V & \(-\)1.67 dB @ 150 GHz & \(<\)20 dB @ 16 GHz & [41] \\ Thermal/Electrostatic & Vertical & 25 V & 1.67 dB @ 5.4 GHz & 33 dB @ 5.4 GHz & [102] \\ Thermal/Electrostatic & Lateral & 0.9 V & \(>\)\(-\)0.1 dB @ 40 GHz & \(-\)20 dB @ 100 GHz & [103] \\ Thermal/Electrostatic & Lateral & 0.16 V & \(<\)1.2 dB @ 40 GHz & \(-\)60 dB @ 35 GHz & [42] \\ Thermal/Electrostatic & Lateral & 0.07 V & \(-\)0.27 dB @ 10 GHz & \(-\)40 dB @ 10 GHz & [99] \\ Thermal/Electrostatic & Lateral & 0.07 V & \(>\)\(-\)0.5 dB @ 40 GHz & \(<\)\(-\)30 dB @ 40 GHz & [104] \\ Electromagnetic/Electrostatic & Vertical & 3.7 V & \(-\)0.37 dB @ 20 GHz & \(-\)34 dB @ 20 GHz & [105] \\ Electromagnetic/Electrostatic & Vertical & 4.3 V & \(-\)0.52 dB @ 20 GHz & \(-\)36 dB @ 20 GHz & [27] \\ Electromagnetic/Electrostatic & Vertical & 15 V & 0.06 dB @ 14 GHz & 50 dB @ 14 GHz & [39] \\ Piezoelectric/Electrostatic & Vertical & 5 V & \(-\)2 dB @ 20 GHz & \(-\)12 dB @ 20 GHz & [106] \\ Piezoelectric/Electrostatic & Vertical & 5 V & \(<\)0.5 dB @ 6 GHz & \(>\)30 dB @ 6 GHz & [33] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Performance of hybrid actuation mechanism RF MEMS switches. Figure 5: Structures of graphene MEMS devices: (**a**) [PERSON] et al. [112]. From [112]. Reprinted with permission from AAAS. (**b**) [PERSON] et al. [113]. Reprinted from [113], with the permission of AIP Publishing. (**c**) [PERSON] et al. [70]. Reprinted from [70]. Copyright 2023, with permission from Elsevier. Subsequently, [PERSON] et al. [113] fabricated a graphene beam-type MEMS switch, as shown in Figure 5b. The good mechanical properties of graphene allowed the mechanical switch to operate at an extremely low actuation voltage (1.85 V). Moreover, research shows that increasing the electrical conductivity of graphene can further improve isolation [114], enhancing graphene's potential application in RF MEMS devices. [PERSON] et al. [53] designed an RF MEMS switch with a graphene-gold composite upper electrode structure, as shown in Figure 5c. Compared to traditional switches, the actuation voltage was only 3 V, and the isolation of this structure improved by 10 dB. The pioneers' work indicates that using graphene can effectively solve the high actuation voltage problem of electrostatic MEMS switches, demonstrating graphene's important role in the future development of MEMS technology. However, current graphene production methods have limitations, especially in the direct acquisition of self-assembled NEMS device structures. For example, the mechanical exfoliation method of separating graphene from bulk graphite is not suitable for the mass production of graphene-based devices. In summary, graphene has clear potential advantages in the application of RF MEMS switch beams, but overcoming challenges in production and integration is necessary for commercialization.