Signal jammer jamming distance relate to device RF putput power, Antenna Gain and surrounding environment ect.
A. Signal jammer Device RF output power and Antenna same, In spacious environment jamming distance will farther then In buildings environment.
B. If surrounding environment same, RF output power more high, jamming distance will farther.
C. Directional antenna jamming distance will farther then omini antenna,
Omini antenna omnibearing 360 degree .
Directional antenna direction is front .
1.Base Station : The base station is the public mobile communication base station, is a form of a radio station and refers to a radio transmission station which transmits information between a mobile communication terminal and a mobile telephone terminal in a certain radio coverage area.
Base station to transmit power 45DBM calculation, the plain area in around two kilometers the basic signal strength of-95DBM, three kilometers at the basic no signal.
2. Environment: Such as atmosphere, obstacle, signal strength, Multipath etc,it will caused transmission distance loss.
3. Interference blocker jammer: The Signal jammer in fact is Electronic countermeasures equipment, In order to make the enemy electronic equipment and systems to lose or reduce the effectiveness of the radio interference measures taken. Is an integral part of electronic confrontation, The purpose is to weaken or destroy the enemy using a variety of electronic equipment and systems to carry out battlefield reconnaissance, combat command, communication and weapons control and guidance of the ability
By the building structure of the wall after the block began to significantly attenuate (single wall is generally 10 15dB)
The bomb Jammer each module RF output power is 50W, ,Jamming distance depend on the signal strength environment. for mobile signal strength if in -50dBm, distance maybe short, if Signal strength in -85dBm, it will can jamming 100m, if signal strength in -95dBm, It can jamming 250m.
4. RF Output power 2W=33dBm 10W=4dBm 50W=47dBm, 100W=50dBm. Each additional 3dBm, Power will be doubled.
5. As bellow introduces the method of calculating the distance of wireless communication when free space is transmitted. The so-called free space propagation refers to the propagation of radio waves around the antenna, which is the ideal propagation condition. When the waves propagate in free space, their energy is neither absorbed by the obstacle nor reflected or scattered.
The communication distance is related to the transmit power, the reception sensitivity and the operating frequency.
Lfs(dB)=32.44 plus 20lgd(km) plus 20lgf(MHz)
In the formula, Lfs is the transmission loss, d is the transmission distance, and the unit of frequency is calculated MHz. It can be seen from the above equation that the wave propagation loss (also known as attenuation) in free space is related only to the operating frequency f and the propagation distance d, and when f or d is doubled, Lfs will increase by 6 dB, respectively.
The following formula illustrates the loss of radio propagation in free space
Los = 32.44 plus 20lg d(Km) plus 20lg f(MHz)
Los is the propagation loss the unit is dB
d is the distance, the unit is Km
f is the operating frequency, the unit is MHz
The following example illustrates an operating frequency of 433.92MHz, the transmission power of plus 10 dBm (10mW), the receiving sensitivity of -105dBm system in the free space propagation distance:
1. The transmit power is plus 10 dBm and the reception sensitivity is -105 dBm
Los = 115dB
2. by Los, f
Calculated d = 30 km
This is the ideal transmission distance, the actual application will be lower than the value, this is because the wireless communication to be subject to a variety of external factors, such as the atmosphere, obstacles, multipath caused by the loss, the loss Of the reference value into the above formula, you can calculate the approximate communication distance.
Assuming that the atmospheric, occlusion and other losses caused by 25dB, can be calculated from the communication distance:
D = 1.7 km
Conclusion: The transmission loss is reduced by one for every 6 dB increase, wireless transmission loss twice
wireless transmission loss every 6 dB increase, transmission distance reduce twice
