The Design of Shielding Mobile Communication System Based on GSM / CDMA / PHS
Yao Xiao-yu · Journal of Hunan Institute of Science and Technology · 2011
A shielding device that simultaneously screen GSM / CDMA / PHS communication tools are designed.It uses continuous emission of high-power uplink frequency interference signals to destroy the data exchange of mobile phones and base stations undermine the coverage area.The device is composed of sawtooth generator,VCO,and RF power amplifier.With a certain frequency of NE555 timer acting on the ramp GSM / CDMA / PHS band VCO,the NE555 timer produces their own communications frequency band signal which,then,is put into the RF power amplifier RF3108.After the signal is amplified,it radiates out by the respective antenna to interfere with a certain range of communication tools,to achieve the purpose of shielding.Through the test,it shows that the system can shield GSM / CDMA / PHS and other communication tools completely;the range of effective shielding is not less than 400m2.