This paper reports on the design, fabrication, and measurement of a new electromechanical implementation for the mitigation of dielectric charging on the signal line and substrate for RF-MEMS shunt switches. Electrostatically shielded, externally-positioned, dielectric-less actuation electrodes with mechanical stoppers are fabricated above the MEMS bridge to isolate the RF and substrate dielectrics from the DC biasing electric fields. In the ON-state, the switch exhibits a measured insertion loss of −0.32dB at 10GHz and −0.69 dB at 20GHz. In the OFF-state, the measured isolation is 15dB at 10GHz and 24dB at 20GHz.