Can Signal Blockers Shield Wired Surveillance Cameras?

In the world of surveillance technology, clients often inquire about the possibility of using signal blockers to shield their cameras. However, before providing a definitive answer, it is crucial to understand the method of signal transmission between the target object (the surveillance camera) and the control terminal of the monitoring system. This article aims to clarify whether signal blockers can effectively shield wired surveillance cameras and provide insights into their limitations.

Understanding Signal Transmission:

To determine the compatibility of signal blockers with wired surveillance cameras, it is essential to ascertain whether the signal is transmitted through video cables or wireless communication technologies. Clients often ask whether signal blockers can shield surveillance cameras that transmit signals through cables. The answer to this question is clear: signal blockers are designed to block wireless signals and are ineffective against wired cable transmissions. Only audio and video signals transmitted wirelessly through monitoring cameras can be effectively shielded.

Wireless Communication Technologies:

The majority of surveillance cameras that utilize wireless communication technologies employ frequencies such as WiFi 2.4G, WiFi 5.8G, or mobile SIM cards for 4G and 5G data communication services. Some cameras also use unconventional frequencies like 433MHz and 1.2G for wireless data transmission. Regardless of the frequency or frequency band used, signal blockers can be equipped with targeted shielding modules to effectively block signals in these wireless communication frequency bands. This process poses no technical barriers or difficulties.

Limitations of Signal Blockers for Wired Cameras:

However, if surveillance cameras are connected through cables, especially those encased in shielding materials, signal blockers designed for full-frequency shielding cannot effectively block these wired cable transmissions. It is important to reiterate that signal blockers can only shield wireless signals.

Exceptions and Interference:

There is one exception to consider. If a signal blocker is placed in close proximity to a surveillance camera or if the antenna of a full-frequency signal blocker is positioned adjacent to the communication cables, some interference may be observed even in the case of audio or video signals transmitted through cables. However, this interference is not consistent or stable, manifesting as screen shaking, blurriness, flickering, distorted audio, and other irregularities. In severe cases, the image may completely disappear, and the audio may become indistinguishable. The extent of interference depends on factors such as the power of the signal blocker, the distance between devices and cables, and other environmental conditions. It is important to note that this interference falls under the category of electromagnetic interference rather than complete shielding.


In conclusion, signal blockers are not suitable for shielding wired surveillance cameras. They are specifically designed to block wireless signals and are ineffective against cable transmissions. While some interference may occur when signal blockers are placed in close proximity to surveillance cameras or communication cables, this interference is not consistent or reliable. It is crucial to consider the power of the signal blocker, the distance between devices and cables, and other environmental factors when assessing the potential for interference.