Design thinking of surge protection scheme for RF port

First, the application background
1 global warming, thunderstorms increased
2 RF many outdoor, vulnerable to lightning
3 transmission rate up to 1Gbps, high junction capacitance requirements
4 high surge protection security equipment become a trend

Two, the protection scheme and from electronic devices

GDT (GDT)
GDT [UN3E5-90LM] DC nominal voltage: 90 + 20%V, impact current (8/20 S): 5kA, capacitance value of 1.5pF, resistance value of 1G ohm;
GDT [UN3E5-90MM] DC nominal voltage: 90 + 20%V, impact current (8/20 S): 10kA, capacitance value of 1.5pF, resistance value of 1G ohm;
Transient suppressor diode (TVS)
TVS [ESD03V32D-LC] Vrwm:3.0V; Vb:4.0V; antistatic ability (contact / air): 8KV/15KV; junction capacitance (f=1MHz): 1.2pF; packaging for SOT-323

Three, program application
1 medical devices
2 video surveillance
3 optical transmitter
4 other RF devices

Four, program description and precautions
1 the front end of the program uses a GDT, parallel with the signal line and the ground between the leakage amplification current;
2 backend TVS junction capacitance of 1 2pF, does not affect data transmission;
3 package for SOD- 323, small size, cost savings; residual down, effective protection RF chip;
4 this program meets I EC61000- 4- 5, GBT17626. 5 surge standard.