June 10,2018 | Edit by:Leo Xu
THE WORKING MECHANISM OF DIGITAL JAMMER:
For wireless communication system, SNR (signal noise ratio) is a key index, SNR will affect stability of wireless communication systems. When SNR is lower than the lowest value of the system requested, communication system will stop. No matter what kind of jamming technology, its jamming mechanism are all the same: worsen the SNR of communication system to infect the receiver, when it cannot demodulate correct data, the communication system will not work normally.
THE WORKING MECHANISM OF VCO JAMMER:
Analog VCO(voltage-controlled oscillator) will produce a CW(continuing working) signal of certain frequency, correspondent with external stable control voltage. When the external voltage constantly changes, it will output a frequency constantly changed CW signal. The constantly changing RF signal from VCO crash with the target communication system, it will worsen SNR of communication system and stop the communication system. Commonly named as sweep jamming(or Scanning jamming).
THE WORKING MECHANISM OF DDS:
DDS(direct digital frequency synthesizer) Digital separating simulated VCO, Its jamming work principle are same as the analog VCO. It is through sweeping and crash with the interfered frequencies, in order to worsen the SNR of the telecommunication system.
THE WORKING MECHANISM OF PSEUDO-RANDOM DIGITAL GUSSIAN WHITE NOISE JAMMING TECHNOLOGY:
With FPGA, by digital coding, generate a noise signal wider as targeted communication system . The whole communication working band will full of noise. Then worsen the SNR of communication system to reach the jamming result.
The Digital White Gaussian Noise is pseudo random signal, its signal characteristics basically meets the random function distribution. So it with a strong jamming ability and don’t need too much power, the lower disturbing radiant power, have less influence and destruction towards the space electromagnetic environment. Have good resistance ability from the influence of long distance attenuate. Jamming source is stable during a long term working. Due to the jamming mechanism, the jamming performance is not obviously influenced by the outside environment(e.g. wind,rain, object moving interference). It don’t need too much RF output power and have few influence on surrounding electromagnetic environment.