## How are cell phone signals generated?

Before figuring out what the signal is related to, we must first understand where our mobile phone signals come from.

The network we are using now is called a cellular mobile communication network, characterized by dividing the entire large-scale area into many small areas. Each small area is set up with a base station responsible for the contact and control of user terminals under the area.

The base station comprises many parts, such as an antenna, feeder, computer room, RRU, BBU, etc. The antenna that has the most direct connection with the mobile phone signal is the antenna.

The inside of this inconspicuous whiteboard is composed of many antenna elements, and the signals are generated by these antenna elements transmitted to our mobile phones through invisible electromagnetic waves.

## How does a cell phone jammer disrupt cell phone signals?

The cell phone jammer usually disrupts the mobile signal by sending interference signals, also known as noise signals. These signals are high power so that they can override telecommunications. When the signals are sent from the cell tower, they can reach your phone because the noise signals interfere with signal propagation. On the other hand, your phone can’t dial out as the signal of your phone can reach the cell tower too.

## What is the signal strength related to?

After figuring out how the mobile phone signal is generated, let’s talk about the signal strength related.

Signal strength is mainly related to the following aspects:

1. The distance from the base station

After knowing the relationship between the signal and the base station, I believe it is not difficult to understand. The closer the distance to the base station, the better the signal, but this is not absolute, and the antenna azimuth and downtilt angle need to be considered.

2. Antenna Azimuth

As mentioned just now, generally speaking, the closer the distance to the base station, the better the mobile phone signal. However, this needs to consider the setting of the antenna azimuth and downtilt angle simultaneously.

Azimuth is the orientation angle of the antenna; 0 ° means due north, 90° means due east, 180° means due south, and 270° means due west.

A base station has three antennas, and each antenna can cover a range of 120°, exactly 360°. For example, if the azimuth angle of the antenna is 0°, then the coverage of this antenna is an area from 300° to 60°, of which 330° to 30° is the main lobe direction, and the rest is the side lobe direction.

If your position is in the main lobe direction, the mobile phone signal will be better; if it is in the side lobe direction, the signal is relatively weak.

3. Antenna downtilt

The downtilt angle is also called the pitch angle, which mainly represents the horizontal angle of the antenna. The larger the downtilt angle is, the closer the base station’s coverage is, and the smaller the downtilt angle is, the farther the base station’s coverage is.

Such a problem occurs due to the existence of the down-tilt angle.

If the downtilt angle of the antenna is relatively small, that is, the antenna is transmitting signals in the horizontal direction. The signal will be very poor when you are closer to the base station, commonly known as “black under the tower”.

4. Power problem

The power mainly includes the base station’s transmit power and the mobile phone’s received power.

The transmit power of the base station is also well understood. The higher the power, the better the coverage and the stronger the mobile phone signal, and vice versa.

The mobile phone’s receiving power mainly represents our mobile phone’s ability to receive signals. The stronger the receiving ability, the better the signal, and vice versa. This is why Apple’s mobile phone complained that the signal is not good, caused by the poor signal receiving ability of its baseband board.