How to measure the range of a signal jammer?

With the rapid development of wireless communication technology, signal jammers have gradually appeared in many fields and become important auxiliary equipment. From creating conditions that simulate a battlefield during military exercises, to restricting wireless signals in certain specific civilian locations (e.g., examination rooms, confidential conference rooms, etc.), signal jammers are indispensable.

However, for a signal jammer to work correctly, you must have a clear understanding of its interference range. On the one hand, a clear interference range helps ensure effective intervention in the target area and achieve the expected management goals, on the other hand, it can also avoid unnecessary negative impacts caused by the uncertainty of the interference range, such as: Interfering with surrounding authorized wireless communication equipment that is not must be affected, resulting in communication failures or legal disputes. How to measure the interference range of a signal jammer during signal measurement?

1. Preparation

(1)Select a suitable testing location: Try to select an open location free of large obstacles (such as tall buildings, mountains, large trees, etc.) to reduce the influence of signal reflection and attenuation on the measurement results. For example, you may choose a large open parking lot, a flat meadow in the suburbs, etc. At the same time, you need to ensure that the electromagnetic environment around the test site is relatively stable and away from other sources of strong electromagnetic interference, such as broadcasting station transmission towers and large substations.

2.Prepare test equipment:

(1) Signal jammer: Make sure it is in normal working condition, and set the appropriate interference frequency and power settings according to the type of signal being tested (such as Wi-Fi signal, Bluetooth signal, mobile phone signal, etc.) .

(2)Equipment experiencing interference: Depending on the type of signal targeted by the jammer, prepare several relevant devices in normal operating condition as test objects. For example, to test a Wi-Fi signal jammer, prepare several laptops, smartphones, etc. with Wi-Fi capabilities. These devices must enable the relevant features and connect to the appropriate network in advance (such as connecting a laptop to a Wi-Fi router before testing, turning on Wi-Fi on a mobile phone and connecting to an available network, etc.) to observe interference. effect.

(3)Signal level measuring instrument: Professional instruments such as spectrum analyzers and field strength meters are used to measure the signal level. A spectrum analyzer can display detailed information such as signal amplitude at different frequencies, and a field strength meter can directly measure the electric field strength at a specific frequency. The appropriate device can be selected according to the actual situation and needs.

3.Testing stages

(1) Arrange the test environment: At the selected test site, place the signal jammer in a relatively fixed location, such as the center of the site or a location convenient for marking and measuring distances.

(2) With the signal jammer in the center, mark equidistant reference points on the ground in different directions (such as east, south, west, north, and at different angles, etc.). The initial distance may start at a location closer to the interferer, such as 5 meters, and then add control points at certain distances (such as 5 or 10 meters) until it reaches a distance beyond the expected maximum possible interference range. For example, you can mark a sequence of control points at equal distances of 5 meters, 10 meters, 15 meters, 20 meters... to form a circular or square pattern of control points centered on the suppressor.

4.Measure the initial value of the signal level:

(1)Before turning on the signal jammer, use a signal strength meter to measure the level of the target signal (i.e., normal signal without interference) emitted or received by the interfered device at each test point, and record it. For different interfering devices and target signals, the specific parameters measured may vary. For example, Wi-Fi signals may require measurement of signal strength, signal-to-noise ratio, etc. within its frequency band, mobile phone signals may require measurement of field strength within its frequency band; etc.

5.Turn on the jammer and observe the jamming effect:

(1) Turn on the signal jammer so that it starts working according to the specified parameters and emits interference signals.

(2) At the same time, quickly use the equipment experiencing interference at various monitoring points to observe the interference. For example, for Wi-Fi devices, you can observe whether it can still connect to the network normally, whether the network speed has dropped significantly, etc., for mobile phones, you can observe whether it can still make calls, send text messages, use data traffic, etc. Fine. At the same time, use a signal strength meter to again measure the target signal level at each test point (that is, the signal level after interference) and compare it with the initial value measured before the jammer was not turned on.

(3) Determine the interference range: Determine the interference range of the signal jammer based on the actual interference observed by the device experiencing the interference and the signal level changes measured by the signal strength meter. Generally speaking, it can be seen that the device affected by interference exhibits obvious interference phenomena (for example, the inability to connect to the network normally, severely limiting communication functions, etc.), and the signal level has dropped significantly compared to the original value (a drop in speed may set the threshold value according to the specific situation, for example: The farthest distance point whose drop is greater than 50%, etc.) is defined as the limit point of the interference range in that direction.

6.Retesting and data processing

(1) Repeated testing: To make the measurement results more accurate and reliable, the above testing process needs to be repeated several times. Each time the test is repeated, some test conditions may be changed, such as adjusting the jammer power (increase or decrease power), changing the jammer placement (slightly shifting the original position), replacing the interfering equipment with a different model, etc., and then repeat the measurement , following the same verification steps. By repeating the test several times, you can obtain more data on the interference range under different conditions and gain a better understanding of the jammer's performance.

(2)Data processing: record the initial signal power of each test point, the signal power after interference, the interference situation of the equipment experiencing interference, and the test conditions (such as the power of the interferer, the location and model of the equipment experiencing interference) recorded in time each testing process, etc.) to organize and analyze data. This data can be presented in tabular form for easy visual viewing and comparison.

Based on this data, you can then plot the signal jammer's interference range under different conditions. For example, a linear diagram, where the power of the muffler is plotted along the abscissa, and the interference range (distance) is plotted along the ordinate. diagram, diagram can be more clearly understood. See the trend of interference range at different powers, etc. Through data processing and analysis, more accurate and scientific conclusions can be drawn about the interference range of signal jammers.