Author: 897918909@qq.com

Most of the mobile phone jammers purchased by customers are equipped with omnidirectional antennas, which originate from the simple cognition that omnidirectional antennas are omnidirectional signal coverage, so most customers imagine the range of shielded signal coverage as: using mobile phone jammers It is a spherical coverage area emitted from the center of the sphere and diffused from the center to the surroundings. Because of this, customers will take it for granted that the installation method of the equipment is very simple, and there is no need to think too much about whether the installation is correct. Then, the problem arises. The mobile phone jammer of the omnidirectional antenna can be arbitrarily placed during installation. let it go?

This question can be discussed and answered from several aspects. First of all, if the mobile phone jammer is only installed in a small space, such as a room with only tens of square meters, which needs to completely shield the mobile phone signal, then this situation It is relatively simple. When installing a mobile phone jammer in such a room, it is more appropriate to install it without too much consideration, because in such a space where the length and width do not exceed 10 meters, any one In the corner or on any side of the wall, the shielding distance of the mobile phone jammer is enough to cover the entire room.

But if the indoor area of a room reaches 100-300 square meters, then at least one of its length and width will exceed 10 meters, or even reach about 20 meters. The current mobile phone jammer, especially the mobile phone jammer with 5G signal shielding, usually has an effective shielding distance radius of 10 meters to 20 meters. In this scenario, if the mobile phone jammer is still installed in a certain If it is a corner, it is very likely to have such a consequence: the area in the room opposite to the shielding device is very likely to be a place that the distance range of the mobile phone jammer cannot reach. In this area, there will be a blind area that shields the coverage of the signal. How to solve this phenomenon? The solution is simple, and the most effective solution is to adjust the installation position of the mobile phone jammer to the middle position appropriately, and use the signal coverage characteristics of the omnidirectional antenna to shorten the distance from the blind area so that the shielding signal can reach the diagonal. area, while maintaining the signal coverage strength of the original location is still sufficient.

In some special application scenarios, high-power portable signal jammers will be favored by users, such as: when the special police face the negotiation scene of hostage rescue, when an emergency needs to block and control the on-site communication urgently, when When suspicious explosives are suddenly found in crowded places, it is very necessary to rely on similar professional equipment to provide technical support in these places. Usually such shielding devices use built-in batteries as the power supply source, so the problem comes, if in the actual application process, the time to solve the problem is lengthened for some reason, the high-power portable signal jammer we mentioned here can Do you work continuously for more than 3 hours?

According to the product technical indicators disclosed by the current mainstream high-power portable signal jammer manufacturers, the nominal RF transmission power can reach above 50W, and the RF module (or RF frequency band) of a single set of portable signal jammers can reach More than 15 can be called practical and meaningful high-power full-band signal jammers. According to preliminary evaluation, for such a set of full-band signal jammers, the total output power of all RF modules is usually between 600W and 1000W. . According to the conventional conversion ratio of 1:3 between RF power and power consumption, we can see that the total power of this type of equipment is about 2000-3000W.

Friends who are familiar with the power consumption of batteries should be able to judge that: if the battery is used to power 2000-3000W electrical equipment, the capacity of the battery must be very large. If we only calculate the power consumption of 2000W, if the output voltage of the battery is 24V, and the high-power portable signal jammer needs to work continuously for 3 hours as a load, the capacity of the battery needs to reach 250Ah after power conversion to meet the requirements.

From the above analysis, it can be concluded that whether the continuous power supply of the high-power portable signal jammer can reach more than 3 hours depends on the capacity of its power supply battery. As long as the battery capacity meets the standard, the power supply time can be guaranteed. However, we should also understand that the larger the capacity of the battery, the larger its volume, and the weight of the battery will also increase proportionally. Even if the most commonly used lithium battery is used, it is conservatively estimated that the bare weight of a 250Ah battery will at least Reaching more than 50Kg, this will inevitably affect the portability of the signal jammer?

When some customers ask us about the demand for frequency jammers, they sometimes make such a request: they hope to only interfere with voice calls and not interfere with communication data. To put it bluntly, I only hope that the mobile phone cannot answer or make calls during the use of the interference device, but this mobile phone can still access the Internet normally, use chat software to communicate with the outside world, and play online games normally. So, can our frequency jammer only interfere with voice but not data?

If we go back to 10 years ago, when we were still in the 2G and 3G era, it was relatively easy for the frequency jammer at that stage to only interfere with voice and not interfere with data. Because the division of labor at that time was like this, 2G mainly handles voice call services, 3G can be used for both voice calls and data transmission, when only the voice call function needs to be reserved, only the 3G in the frequency jammer needs to be Just keep the band on. Of course, although a data communication with a very low network speed is still reserved in the 2G frequency band, such a low communication rate cannot meet the data traffic demand on the mobile application side.

Then when we have experienced 4G and entered the 5G communication era, the division of mobile phone communication frequency bands has been greatly adjusted and changed compared with 10 years ago. The original 2G frequency band has already started the frequency and network decommissioning project, and many places have already demolished the original 2G mobile phone base stations. A large part of the original 3G frequency band was changed to 4G frequency band for use. Moreover, 3G, 4G, and 5G mobile phone standards all support voice and data at the same time, which has brought about a consequence: we can no longer distinguish voice and data from the working frequency of the mobile phone. In the same way, we cannot make an effective distinction in the setting and selection of the interference frequency of the frequency jammer.

So the final conclusion is already obvious, these common frequency jammers can no longer only interfere with voice calls, but not interfere with data transmission.

Some outdoor application places generally choose high-power
mobile phone jammers, such places include but are not limited to: prison farms, oil depots, power stations, gas storage stations, mining areas, etc. Their common characteristics are: a wide area, a large open area, and a large-scale building structure inside. When the above-mentioned units choose high-power mobile phone jammers, they often pay attention to one point: it is hoped that the shielding distance of the shielding equipment will be as large as possible. Effects that override the entire unit. Then the question arises: what is the maximum shielding distance of the existing high-power mobile phone jammers? Is there any shielding device that can shield distances above 1Km?

What we are discussing here is specifically the shielding distance for mobile phone signals. Check and compare the product information of various high-power mobile phone jammer manufacturers. Even if the power is 100-200W, its nominal effective shielding distance is generally 200-500 meters. Almost no manufacturer can achieve a nominal value of effective shielding distance above 1Km. Why? There are two main reasons. The first is the selection of RF power amplifier devices. The maximum power of the mainstream RF power amplifier devices on the market usually can only reach 200W. No matter how high the power is, it is possible that the shipments are too small, the cost of the device is too high, or special customization is required from the power amplifier manufacturer. This has caused manufacturers of high-power mobile phone jammers to give up choosing such ultra-high-power power amplifiers due to cost issues. The second reason is that the current mobile phone base stations are very densely deployed, especially in the main urban area of the city, there will be at least two or even more mobile phone base stations within a randomly selected 1Km range. We should all know that the shielding distance of mobile phone signals depends on the distance between the mobile phone jammer and the mobile phone base station, and the relationship between the two is inversely proportional.

Through the above analysis, we can know that the high-power mobile phone jammers that can be selected now have a nominal shielding distance of only about 500 meters at most. Coverage distance of more than 1Km. However, if it is in a sparsely populated area in the wild, and the base station construction distance is several kilometers apart, it is possible that a single set of high-power mobile phone jammers will have a coverage distance of 1Km.

In recent years, with the increasing number of users buying and using 5G mobile phone signal jammers, when users give us feedback on their experience, they usually talk about the shielding distance, and most of them hope that the shielding distance can be as long as possible. Make it bigger, and even in some relatively open areas, it is expected that one or two shielding devices can solve all the problems of mobile phone signal shielding. Then the question immediately came out, is there an upper limit for the shielding distance of the current 5G mobile phone signal jammer? If there is an upper limit, what is the upper limit value of this shielding distance?

But any customer who has a certain degree of understanding of 5G mobile phone signal jammers will know that the effective shielding distance of 5G signals is closely related to the environmental signal strength of the use site. The distance between the base station and its distance determines the size of the shielding distance. If the 5G base station is more than 1Km away from the scene, then the 5G mobile phone signal jammer will have a large working distance, and the effective shielding radius will reach tens of meters. If the distance between the 5G base station and the scene is only three or four hundred meters, then the working distance of the 5G mobile phone signal jammer will be much shorter, and may only be kept at about ten or twenty meters. If the distance between the 5G base station and the site is less than 200 meters, the consequences will be more serious. Conventional low-power 5G mobile phone signal jammers can hardly play a shielding role, and the radius of their effective shielding range may only be 1-2 meters.

After knowing the above analysis, how should the upper limit of the shielding distance of the 5G mobile phone signal jammer be determined? Obviously, this upper limit must be inseparable from the distance between the on-site environment and the surrounding base stations. In addition, there are two important influencing factors: one is the RF transmission power of the shielding device, and the other is the antenna used by the shielding device.

Let’s look at the first point first. Regarding the RF transmission power of 5G mobile phone signal jammers, according to common sense, the greater the transmission power, the greater the effective distance. At present, the maximum RF power can basically achieve a single frequency band module of 100-200W, and the corresponding effective distance is about 200-500 meters.

Looking at the second point, regarding the antenna used by the 5G mobile phone signal jammer, there will be two choices: using a high-gain directional antenna, its effective shielding distance will definitely be far greater than using a low-gain omnidirectional antenna , but the use of directional antennas only increases the shielding distance in the targeted direction, and gives up a large part of the effective shielding range in the lateral and rear areas.

The shielding range marked in the technical indicators of conventional mobile phone jammers usually refers to a transparent environment. For example, in an indoor room, under normal circumstances, a jammer can cover the entire room, but some customers will also propose some other application scenarios: when the user of the mobile phone jammer starts working in a room, it can The area that really needs mobile phone signal shielding is the room next door or the room further away. Then the question arises: Is it possible to shield mobile phone signals across several rooms in reality?

To understand and solve the above problem, we need to analyze it from two angles: the first angle: the radio frequency signal emitted by the mobile phone jammer, the ability to pass through the wall during the transmission process of the partition. The so-called wall-penetrating ability of radio frequency signals is actually the attenuation ability of wireless signals for different wall materials. To realize mobile phone signal shielding, it is necessary to require the shielding signal of the mobile phone jammer to be strong enough to minimize its attenuation during transmission. But if it is unavoidable to encounter the obstruction of the wall, a part of the wireless signal will be directly reflected or refracted, and only a small part will directly penetrate the wall. And the size of the penetrating ability depends on the material of the wall. The well-known reinforced concrete walls are much more attenuated by radio frequency signals than conventional brick walls. The attenuation capacity of brick walls is much greater than that of wooden walls or glass walls. If there is a room in the middle, it means that the radio frequency signal needs to penetrate at least two walls. Unfortunately, after passing through two reinforced concrete walls, the shielding signal of the mobile phone jammer can basically be attenuated to a very low level. To a certain extent, it is basically impossible to achieve mobile phone signal shielding.

The second angle is the strength of the mobile phone signal environment on site itself. Because the effect of mobile phone signal shielding is related to the signal strength of the mobile phone base station received at the scene, that is, when the mobile phone base station is farther away, the mobile phone signal at the scene will be quite weak. At this time, when using a mobile phone jammer , the effect of mobile phone signal shielding will be very good. But looking at the situation the other way around, if the mobile phone base station happens to be very close to the scene, it is already relatively difficult to use a mobile phone jammer to shield the mobile phone signal in the room where you are. In this scenario, you still hope that the radio frequency signal can pass through. The wall, and also achieve the effect of mobile phone signal shielding for adjacent rooms, which is obviously unrealistic.

A customer wanted to buy a
wireless signal jammer from us, and described their installation and use environment: their unit is a three-story building, the first floor is the factory workshop, the second floor is the office area and meeting room, and the third floor It is workshop and warehouse. After the wireless signal jammer was purchased, it was ready to be installed in the meeting room on the second floor, but there was a key requirement: the shielding range was limited to the meeting room, and it could not affect the wireless signals on the upper and lower floors and the normal use of mobile phones. Then the question arises, is it possible to install a wireless signal jammer in the conference room on the second floor without affecting the first and third floors?

If it is absolutely necessary to guarantee that it will not affect other floors, it is basically impossible. Because the transmission mode and transmission characteristics of the wireless signal determine that it cannot achieve a one-size-fits-all effect, that is to say, the shielding signal emitted by the wireless signal jammer, its transmission boundary is impossible to use the walls around the conference room as the boundary And the deadline. Although the floor and ceiling of the meeting room are solid floor partitions, the RF signal will experience a very large attenuation when it penetrates the floor, but after all, there will still be a certain amount of signal that can penetrate through it, but the energy and intensity are much reduced. That’s all. On the other hand: there are different numbers of doors and windows on the walls around the meeting room, and the shielding signal of the wireless signal jammer will have different degrees of refraction and reflection when encountering walls, doors, windows, etc. in the meeting room. There are even direct transmissions to the outside world through doors and windows. The attenuation caused by this phenomenon is not large, and it will inevitably have a certain impact on other rooms on the upper and lower floors. If you want to ensure that the first and third floors are not affected, there is a simple and crude way: completely seal the conference room with a metal plate, the characteristics of the metal plate can make the jammer number of the wireless signal device almost completely blocked in the closed area. inside the cavity space. But it is obvious that this solution is completely unacceptable and does not have practical operability.

When the wireless signal jammer is installed in the meeting room on the second floor, we can only look at this problem from the perspective of minimizing its impact on the upper and lower floors. How to minimize the impact? The method can still be provided for reference: first, install the wireless signal jammer as far away as possible from the window side of the outer wall, that is, install the jammer as far as possible inside the building. Secondly, manufacturers of wireless signal jammers are required to configure directional antennas for the equipment. Finally, confirm that the conference room is made of reinforced concrete walls, and try to avoid walls of gypsum boards or walls of glass partitions.

In recent years, the demand for vehicle-mounted
frequency jammers has been greatly improved, especially in terms of high-power models, which are particularly favored by police departments. However, in the stages of vehicle modification and equipment integration during the equipment selection and delivery process, there will always be a topic that makes people particularly entangled: customers originate from the consideration of concealment when performing tasks, and strongly hope that the antenna on the vehicle can be inconspicuous , unassuming, and even better not to be seen or recognized by others. Then the question arises: Can the antenna of the car frequency jammer be installed directly inside the car for concealment?

The conventional construction plan is to install the antenna of the vehicle-mounted frequency jammer on the top of the vehicle. The advantages of this are obvious: the first advantage is that the height of the vehicle roof is used reasonably. When the vehicle-mounted antenna is erected on the roof, the antenna The emitted interference signal can obtain a larger signal coverage, and in the process of transmission to the surroundings, it can basically overcome the blocking effect of vehicles on other roads. The second advantage is that the installation space on the roof is relatively generous. Even if the number of antennas configured for the vehicle-mounted frequency jammer reaches more than 10, the space on the roof is sufficient to accommodate it. The third advantage is that the roof can also be equipped with an antenna lodging mechanism. When the equipment is not powered on, all the antennas can be stored lying down.

However, the disadvantage of installing the antenna on the roof is also obvious, that is, in the working state, several antennas erected on the roof will be very conspicuous, making the vehicle frequency jammer highly recognizable, and it is too easy for the outside world to see that this is A special vehicle for special operations. So its concealment is almost zero.

So if the car antenna is not installed on the roof, but all installed inside the car, is it feasible to do so? The answer is very clear: such an approach is extremely inadvisable. The reasons include three aspects: First, the carriage itself is composed of a relatively closed metal frame and metal sheets. This structural feature will interfere with the vehicle frequency jammer. The transmission of the signal produces a very large attenuation effect, which undoubtedly greatly reduces the interference performance of the interference device artificially. The second reason is that the antenna is installed in the car, and the height of the antenna from the ground is also reduced a lot. The reduction of the height will cause the interference signal to be easily blocked by surrounding vehicles or low objects. The third reason is that this kind of high-power vehicle-mounted frequency jammer and the high-power radio-frequency interference signal emitted by the antenna are close to the antenna. The intensity of its electromagnetic radiation is harmful to the body of the driver and passengers inside the compartment Health is extremely unfavorable.

In the current various types of examinations, the examination room
jammer has almost reached complete popularity. It has been used as an important guarantee weapon to maintain the order of the examination room and ensure the fairness and impartiality of the examination. In the process of building a standardized test room, various test supervisory units often ask our manufacturers such a question: In the classroom as the test room, where is the ideal installation position for the test room jammer?

A few years ago, when the jammers in the examination room were only for signal shielding of 2G and 3G signals of mobile phones, some examination rooms did not adopt the method of fixed installation of the jammers, but distributed them uniformly before the exam and unified after the exam. way of recycling. But the consequences of doing so are: the storage and maintenance of the equipment is more troublesome, in the process of distribution and recycling, it is easy to inadvertently damage the equipment, and sometimes it is easy to lose the parts of the equipment. Later, when the 4G and 5G signals became common, the test room jammer went through several iterations, and the size, frequency band, and number of antennas of the equipment increased a lot. If the method of centralized distribution and recycling is adopted, more workload will be added, and the It makes the pre-examination preparations more troublesome, so it has become an inevitable choice to install the test room jammer in the classroom.

The most common installation method is wall-mounted installation, so the question is, a classroom has four walls and a top surface, where is the ideal installation position for the wall-mounted test room jammer?

First of all, the most convenient and reasonable location is the area on both sides and above the blackboard on the front and rear walls of the classroom. Usually, in the area mentioned above, at least one blank space will be found that can be used to install the test room jammer on the wall, and the height after installation is just right, which meets the installation height requirement of 1.8m-2.5m. This can not only meet the requirements of signal coverage, but also prevent students from easily touching the jammer and maliciously damaging the device.

Secondly, the walls on both sides of the classroom in the examination room are relatively centered. When choosing such a location for installation, it is usually because the mobile phone base stations around the examination room are relatively close, resulting in a relatively small shielding radius of the jammer in the examination room. In this way, the radiation characteristics of the omnidirectional antenna of the device can be fully utilized, so as to take into account the overall coverage effect in the classroom of the examination room.

Finally, let’s talk about whether the top of the classroom can also be used as the installation location of the test room jammer. Choosing to install on the top of the classroom and in the center can actually maximize the performance of the jammer, but this choice of location is rather extreme. First, this approach is not beautiful and affects the environment of the classroom. Second, it needs to be considered There may be a beam on the top. When there is a beam, in order to prevent the beam from attenuating the signal of the jammer in the test room, the equipment must be installed at the bottom of the beam.

When customers ask us about the product functions and technical specifications of the shielding equipment, they sometimes make such a clear request: can the shielding distance of the 5G mobile phone jammer they want to purchase be accurately controlled at a position of 5 meters or 10 meters? Because customers are very strict on the distance control of the use site, they don’t want the shielding distance to be too large, and they don’t want the shielding distance to fall short of the required coverage. So, can such a requirement be met?

We have to understand the customer’s on-site situation in detail before we can make an analysis and answer. If the customer installs the 5G mobile phone jammer in a relatively isolated indoor space, there is a solid reinforced concrete wall at a distance of 5 meters or 10 meters from the installation position of the 5G mobile phone jammer. During the transmission process, when encountering a wall, part of the signal will be refracted or reflected, and part of the signal will penetrate the wall, but this penetration process will be greatly attenuated, passing through the wall The strength of the shielding signal will be greatly weakened, and the ability to shield the mobile phone signal has not been reached. This means that if there is isolation or blocking by the wall, the signal attenuation effect of the wall can be used to basically achieve accurate shielding. transmission distance. However, it should be noted that only a completely solid reinforced concrete wall can have a greater attenuation effect on the shielding signal. If it is replaced by a gypsum board partition wall, a wooden partition wall or a glass partition wall, then the wall is used as the control 5G mobile phone The shielding distance approach for jammers will no longer be feasible.

If the usage scenario required by the customer is another form: the 5G mobile phone jammer is installed in a relatively open or very large indoor space, and there are no obstacles within tens of meters around it. In this scenario, It is still required that the shielding distance be accurately controlled at a position of 5 meters or 10 meters. To tell the truth: such a requirement is basically impossible to achieve in the field of radio frequency signals.

The actual effective shielding distance of the shielding signals of various standards emitted by the 5G mobile phone jammer is not exactly the same, it depends on the strength of the mobile phone signal at the scene, or depends on the surrounding mobile phone base stations of various standards distance. Moreover, in the process of the shielding signal diverging and transmitting in the air, the signal strength value is a process of gradually attenuating and weakening. In the case of obstacles, it is impossible to achieve a one-size-fits-all effect, and it is impossible to accurately control the shielding signal. At a certain specified distance, the signal suddenly disappears or is cut off.

A standard cell phone signal jammer, because it needs to take into account all 2G, 3G, 4G and 5G frequency bands must be effectively shielded at the same time, so generally no less than 10 signal shielding modules are installed inside it, each of which shields The modules will correspond to a cell phone frequency band respectively, so the question arises: in the conventional cell phone signal jammer, which frequency band modules are universally interchangeable?

At the beginning of answering this question, we should first have a general understanding of how the current cell phone frequency bands are divided, and the frequency values occupied by each cell phone frequency band.

According to the internationally accepted cell phone communication frequency band division standard and our domestic actual implementation standard, by the end of 2022, the frequency range occupied by the cell phone communication frequencies we currently know is between 700MHz and 4960MHz. Among them, 4800MHz-4960MHz is classified as the 5G frequency band of China Mobile and China Radio and Television, but this frequency band belongs to the ultra-high frequency cell phone frequency band. At present, there is no preparation for large-scale promotion and deployment in China, and it is only deployed as a communication network in specific places. application only. Therefore, conventional cell phone signal jammers generally do not need to consider configuring the 4800MHz cell phone shielding module for the time being. When the 4800MHz frequency band is excluded, the communication frequency band of cell phones is actually mainly distributed between 700MHz and 3600MHz.

Let’s analyze in detail the characteristics of the frequency band division between 700MHz and 3600MHz. In this large frequency range close to 3000MHz, the cell phone frequency band is not completely occupied, but is mainly distributed in several intervals. These sections are: 700MHz, 800MHz, 900MHz, 1800MHz, 1900MHz, 2000MHz, 2100MHz, 2300MHz, 2500MHz, 3400MHz and so on. As a manufacturer of cell phone signal jammers, when designing and formulating shielding modules for the above-mentioned cell phone frequency bands, according to the matching parameters of electronic components such as power amplifiers and signal sources, some of the frequency bands will be combined or share the same set of device combinations. Among these frequency bands, the most common frequency bands that share a group of devices are 800MHz/900MHz, 1800MHz/1900MHz, 2000MHz/2100MHz, 2300MHz/2400MHz, 2500MHz/2600MHz, 3400MHz/3500MHz and so on.

From the frequency band parameters listed above, it can be concluded that although there may be more than 10 different shielding modules in a cell phone signal jammer, in fact there may be at least 4 to 6 module groups of the same style among them. The two modules in the group are universally interchangeable, but they will correspond to the respective cell phone frequency bands by adjusting the frequency offset and bandwidth during factory debugging.

In most cases, when installing and using a mobile phone signal jammer, it is required to shield the mobile phone signal and the WiFi signal at the same time. The WiFi signal here includes WiFi2.4G, Bluetooth, WiFi5.8G, etc. However, there will also be some occasions with special requirements.

Customers will request that the mobile phone cannot make calls or chat online, but at the same time retain the smooth transmission of WiFi signals. The reason why there is such a requirement to reserve WiFi signals separately is because there may be There are working equipment and instruments that must rely on WiFi signals for communication. Once the WiFi signals are shielded while shielding the mobile phone signal, the normal working status of these devices will be affected. So for such a situation, can our mobile phone signal jammer block the mobile phone signal without affecting the WiFi signal?

In fact, this problem is not difficult at all for our mobile phone signal jammer manufacturers. Customers only need to express to us clearly the usage scenarios and clear requirements before ordering the shielding equipment. No need to shield WiFi signals, then we will produce and assemble When using the mobile phone signal jammer, the shielding modules of the WiFi2.4G frequency band and WiFi5.8G frequency band are no longer selected for installation, so that the finished products produced in this way will undoubtedly not have shielding and interference effects on WiFi signals.

After deciding not to install WiFi2.4G and WiFi5.8G shielding modules, there will actually be two more modules inside the mobile phone signal jammer. Customers can then have two options: the first The choice is to keep the status quo, and only install shielding modules that are purely for mobile phones, so that the production cost of shielding equipment will be reduced, and manufacturers will also give certain price discounts accordingly. The second option is to use the two extra module installation positions and ask the manufacturer to give suggestions to split the individual frequency bands with particularly strong signals or large frequency coverage, so as to improve the shielding effect of the mobile phone frequency band.