UHF Reader, UHF is an acronym for Ultra High Frequency with the frequency range of 300–3,000 MHz (0.3 to 1 GHz) at the wavelength of 1~ 0.1m of the spectrum. UHF waves are very weak in nature, hence easily reflected by the ionized layer of the upper atmosphere but can be concentrated in highly directional narrow beams. UHF permits for the transfer of much more information because higher frequencies can be multiplexed proportionally onto the carrier (transmit frequency).
The applications are wider from television to many applications including UHF readers used for parking management and access controls. The UHF RFID readers are highly used in the commercial environment and have a very simple but specific working principle.
The UHF long range reader s are designed to work at the frequency range of 300 – 1,000 MHz (0.3 to 1GHz) and 433MHz using far field or back-scatter coupling principle. Coupling is the process of transferring energy from one medium to another. The coupling used depends on the inductive or radiative fields, near-field effects are used by inductive coupling while far-field effects are used by back-scatter coupling. In general RFID systems using the inductive coupling operate at 125–135 kHz and 13.56 MHz operate in the near-field, while those operating in far-field using beyond 100 MHz, such as 860–960 MHz, 2400MHz, 5800 MHz use back-scatter coupling.
The commercial UHF reader from Nundnet comply with the UHF Gen2 standard and use the 860 to 960 MHz band & 900 and 915MHz.
Many systems, referred to as combo systems use the combination of Low & Ultra High frequency. This way the use of multiple devices is eliminated. Assume a location using Mifare readers in office & UHF readers at the parking area, then the company has to allocate two cards for the user, in such cases we can go for the combo card that uses a combination of Mifare & UHF frequency card.