This paper presents a RF to mm-wave switch based on Germanium Telluride phase change material. An integration process compatible with a standard CMOS back end of line is proposed to realize directly heated switches. RF measurements, performed up to 65 GHz, show an ON-state resistance of 1 Ω with an OFF-state capacitance of 7 fF corresponding to a 22 THz cutoff frequency which constitutes a state-of-the-art Figure-of-Merit. Switching time of only 60 ns in both phase changes allow energy consumption one decade lower than the state-of-the-art for crystallization. A geometrical variation of GeTe dimensions shows a linear evolution of RF performance in terms of ON-state resistance and an almost unchanged performance in the OFF-state.