WHAT IS ULTRA HIGH FRECUENCY (UHF)
Ultra high frequency (UHF) means radio frequencies between 300MHz and 3GHz, with wavelengths ranging from one meter to one decimeter. Higher and lower frequency signals than UHF.
RFID SECURITY SYSTEMS
This radio frequency is adequate for RFID security systems, television broadcasts, cell phones, satellite communications, GPS, and personal radio services. Also, it is sufficient for Wi-Fi and Bluetooth, walkie-talkies, cordless phones, satellite phones, and other security-related applications.
UHF RADIO WAVES
Ultra high Frequency propagate primarily by line of sight so that large buildings can block them. However, transmission through walls is sufficient for indoor reception.
RFID ANTENNAS
One of the main applications of this frequency range is in RFID Antennas. As mentioned above, radio waves in UHF travel by line of sight (LOS) and ground reflection. Therefore, there is little or no reflection from the ionosphere (propagation of sky waves) or ground waves.
RFID SECURITY SYSTEMS
Since the wavelengths of UHF waves are similar to the size of buildings and other familiar objects. Besides, reflection and diffraction from these objects can fade due to multipath propagation. Mainly, it happens in urban areas with RFID access control.
Another aspect to consider is atmospheric humidity; this reduces the intensity of UHF signals over long distances. The attenuation increases with frequency. After the above, UHF allows a reach in neighboring geographic areas for frequency reuse.
Radio repeaters are helpful for retransmitting UHF signals when a distance greater than a line of sight is required. This can be useful in large areas where you implement RFID vehicle access control, and several control points are needed.
THE LENGHT OF AN ANTENNA
2.5-25 CM LONG
The most common omnidirectional antenna.
