Why Do Antenna Masts Sometimes Have Bad Signal

In the last blog, we mainly introduced the working principle of the antenna mast, that is to say microwave communication.

Different from the transmission methods of modern communication networks such as coaxial cable communication, optical fiber communication and satellite communication, microwave communication directly uses microwaves as a medium for communication, and does not require a solid medium. Microwave transmission can be used when the straight-line distance between two points is barrier-free.

The use of microwaves for communication has the characteristics of large capacity, good quality and can be transmitted to a long distance, so it is an important communication method in the national communication network, and is also generally applicable to various special communication networks.

Why do antenna masts sometimes have bad signal?

Microwave transmission will be fading due to the interference of many external factors. Sometimes the duration of fading is very short, within a few seconds to several minutes, which is called fast fading, and sometimes the fading time lasts for ten minutes or even several hours, which is called slow fading. The reception level higher than the normal level is called upper fading, and the lower level is called lower fading. The reception level below the minimum reception level of the receiver is hereinafter referred to as deep fading.

The effect of space fading on microwave communication mainly has two aspects: one is the reduction of the receiving level, which is called flat fading; the other is the distortion of the transmission waveform due to the frequency selectivity of fading, which is called frequency selective fading.

What are the possible reasons for the poor signal?

✔️Absorb fading

Oxygen molecules and water molecules in the atmosphere can absorb energy from electromagnetic waves, resulting in energy loss and attenuation of microwaves in the process of propagation. The higher the frequency and the longer the station distance, the more severe the fading.

✔️Scatter fading

The large and small water droplets in the rain and fog can scatter the energy of the electromagnetic wave, thus causing the energy loss of the electromagnetic wave and fading. In rainy and foggy weather, it has a great impact on high-frequency microwaves.

✔️K-type fading

Interferometric fading due to multipath transmission. Because this fading changes with the change of the refraction parameter K of the atmosphere, it is called K-type fading. This fading is especially severe on water surfaces, lakes, and smooth ground.

✔️Waveguide fading

Due to the influence of meteorology, uneven atmospheric ducts are formed in the atmosphere. When the microwave rays pass through the atmospheric waveguide, the electric field strength of the receiving point includes the reflected waves outside the "waveguide layer", resulting in severe interference-type fading and interruption of communication.

✔️Flicker fading

Atmospheric turbulence often occurs in the atmosphere in the troposphere, and the uneven block-like layers formed by the atmospheric turbulence make the dielectric coefficient different from the surrounding. When the microwave radiation hits the uneven block-like layer, it will radiate the radio wave to the surrounding, forming tropospheric scattering. At this time, the receiving point can also receive the scattered wave from multipath, resulting in fast fading. Since this fading is due to multipath, it is called scintillation fading.

Techniques to combat these fadings include adaptive equalization, automatic transmit power control (ATPC), forward error correction (FEC), and diversity reception techniques.

In conclusion

In the above content, we mainly introduce the reasons for the weak signal of portable antenna tower mast. For more solutions, contact us and we will provide you with feasible suggestions. We are antenna mast group supplier, if you want antenna tower mast wholesale, we will be your best choice.