How Are UHF RFID Systems Operational?

Through RFID antennas, the RFID reader generates radio waves at particular frequencies. The waves “give energy” to the tags, enabling them to exchange a distinct ID through communication. They last for a long time and don’t require batteries. In order to incorporate the data into our program and give it meaning, the reader processes the data. A reading range of 0 to 12 meters is usual. Readers, antennae, printers, and RFID tags or labels make up Gen2 UHF RFID systems. I will outline and briefly explain each of the key components involved in putting an RFID project into action in this post.

Read More: UHF RFID Inlays

Radio frequency antennas

The waves that RFID antennas broadcast and receive enable us to identify RFID chips. An RFID chip is triggered and sends out a signal when it passes across the antenna field. The antennas span varying distances and produce distinct wave fields.

Antenna Type: In circumstances where the orientation of the tag fluctuates, circular polarization antennas perform well. When the orientation of the tags is known, regulated, and constant, linear polarization antennas are employed. RFID tags are scanned using NF (Near Field) antennas, which may reach a few millimeters.

Overcast angle and gain: We can emit more power and get a higher reading ratio by using antennas with gains of at least 8.5–10 dbi. The area to be covered determines the angle of opening, which can range from 70 ° to 100 °. The detection distance decreases with increasing antenna overture.

Antenna count: Normal high-performance readers come with two, four, or eight ports. The reading space we wish to detect or the density of tags to read are normally taken into consideration while determining the number of antennae. A fixed reader with two or four ports is usually utilized. Multiplexers from some companies enable us to link up to 32 antennas to a single reader.


There are several kinds of readers: USB readers, fixed RFID readers, portable RFID readers, and RFID readers for smartphones. For high tag density reading or 100% detection accuracy, the Impinj R420, ThingMagic M6e, and Zebra FX9500 are the finest fixed RFID readers. Additionally, we suggest the Zebra MC9190, Impinj AB700, and Zebra RFD8500 as portable readers if necessary. A number of considerations must be made in order to select the appropriate reader:

Reading area: Fixed readers are mostly used to cover a single spot, such as a box, a doorway, a machine, or a conveyor belt. We can read while on the go, do inventory, and look for RFID tags that we are not seeing with mobile readers.

Ratio of reading: The quantity of tags to be detected in a given amount of time dictates the emission power and reading capacity needs. Applications with a high density of tags, liquids, or metal items are the most complicated. The regulations that each nation or zone is permitted to impose based on the kind of frequency (ETSI, FCC) indicate the maximum reading power.

The kind of RFID reader: Often, the decision is made between a fixed and a portable reader. The application determines this factor. Using a portable terminal is helpful, for instance, if we need to take inventory and make moves in a store or warehouse. Installing a reader that covers the whole reading area and leaving the work automatic is convenient if the reading area is fixed. For instance, to find merchandise or pallets in shipping zones.

USB Readers: These readers work really well when we need to read or record a small number of tags at various stages of the production process or when we need to validate papers in offices. The Nordic Stix and the ThingMagic USB Reader are two prime examples.

RFID tags and labels

The size, orientation, reading angle, location, and kind of chip are the crucial elements.

Dimensions: the chip’s size is crucial for the straightforward reason that an RFID tag’s sensitivity and detection improve with its number of antennas. We may subsequently create dependable and strong apps regardless of whether the tag’s response is consistently the same or extremely similar each time it is recognized. Copper or aluminum are typically used to make the antennas.

Orientation and reading angle: We do not need to worry too much about orientation if our antennas are circular. When we use linear antennas to detect the tags, the orientation of the tags is concerning. In this instance, like with the ShortDipole tag, we have to determine if the tag’s ideal placement is vertical or horizontal. FROG 3D and WEB are two examples of omni-directional antennas with two dipoles that enable us to identify tags in any orientation. Due to the antenna’s design, they often have a smaller reading range.

These are the RFID tag’s internal chips, or integrate circuits (ICs). The Impinj Monza, NXP, and Higgs are the most often used. ICs with 96 bits to 512 bits of memory are available. They can lock with passwords, feature an EAS alert system, and have more memory. Additionally, some integrated circuits (ICs) combine NFC and RFID technology into a single chip. We can store more memory in an external database and link it with an ID that uniquely identifies the chip when needed.

Location area: To ensure that the RFID solution is successful and satisfies the required reading ranges, it is crucial to consider where the attached tag will go. Remember that water absorbs radiofrequency waves whereas metal reflects them. We can accurately recognize metal labels by placing them on the metal thanks to solutions for metal labels. Environmental conditions including indoor and outdoor temperatures, as well as other specific uses like monitoring food or drugs, dictate the type of material and adhesive that should be utilized.

RFID price tag: If the application calls for a high number of tags, this will undoubtedly be the most crucial element in determining cost and calculating return on investment.


We frequently ponder how to encode the data within the tags. We are able to encode the chip and print any bar code or number using RFID printers, like the Zebra printers ZT410 0 R110xi. Additionally, we can encrypt tags using portable, stationary, or USB readers. Where should we encode the data, though? Typically, the EPC or TID is read while reading the tags. TIDs are made up of a distinct number that is generated at the manufacturer and cannot be changed. What is captured, altered, and with which we often interact is the tag’s EPC space. We may store more data in the internal memory of the tags, which is called user memory.