Selecting a suitable antenna is an integral part of any RFID-based product or solution. An antenna on an RFID system determines power consumption, range of communication, system efficiency, and reliability. As such, they play a vital role in the system. In particular, UHF RFID systems require sophisticated infrastructure considering the various technical specifications that are associated with system performance needs. This article provides guidelines to make the right choice while selecting a passive UHF RFID antenna for your application.
What Are The Important Specifications Of Passive UHF RFID Antennas?
Antenna choice has to be considerate of several vital parameters that drive the entire system. Such essential parameters on a passive UHF RFID antenna include frequency, beam pattern, polarization, gain, and finally communication range. Here we will go through each of these parameters as well as their importance in the system.
Frequency:Yes, there are different frequency ranges of UHF RFID antennas based on their compliance with a particular country’s regulations. Prominently, there are three frequency ranges that are often used in worldwide RFID implementations:
> In USA as per FCC: 902-928 MHz
> In Europe as per ETSI: 865-868 MHz
> Globally used: 860-960 MHz
The targeted market region is the driving factor for defining the antenna frequency.
Gain:Gain is the determining factor for beamwidth as those two are related. Essentially, gain also determines the range of radio wave propagation. For instance, higher gain allows lower bandwidth and a more extended range of propagation. Gain is also vital to ensure that the reading is done precisely with a higher signal-to-noise ratio.
Beamwidth:As mentioned, gain also affects the beamwidth. Narrower beamwidth would reflect as higher gain and higher range of transmission. If tags are to be scanned at a shorter length in various directions, an antenna with wider beamwidth can be ideal for such an application. Beamwidth and the other radiation parameters play a significant role in building a better RFID communication system.
Polarization:In general, UHF RFID passive antennas can either be linearly polarized or circularly polarized. To dive deeper, linearly polarized antennas can send RF radio waves in a single direction, e.g., vertical or horizontal. A circularly polarized antenna can propagate radio waves in a clockwise or anticlockwise circular motion. Using both circularly polarized antennas together can improve the read range.
Range:An antenna can help determine the range of transmission and range of reading RF tags from a distance. Therefore, it is a critical parameter to consider in any RFID system. Choosing an antenna with a lesser range can result in loss of readings while selecting an antenna with a higher range can allow adversaries to eavesdrop on the radiowaves.
Passive UHF RFID antennas are being used in several applications, including inventory management & tracking, anti-counter-fitting applications, and wireless device configuration. Such applications often aim to enhance the customer experience by being more reliable, efficient, and uniform with its operation for different situations. Choosing an RFID antenna that meets these given characteristics would play a significant role in RFID system architecture and end application’s effectiveness.