RFID Wireless Systems

What is an RFID wireless system? 

Radio Frequency Identification (RFID) systems use radio waves to identify an object using a reader to communicate with a tag. The tag is physically attached to an object that is identifiable or trackable.

There are several types of RFID systems grouped by either “passive” or “active” type, by operating frequency, and by application. As the name suggests, a passive RFID system consists of a tag that does not have an onboard power source. Instead, when in range, the tag collects energy from the electromagnetic field received from the reader via the tag's loop antenna and rectifier circuitry.

Depending on the type of RFID system, the tag sends a feedback signal to the reader with some encoded data on the carrier frequency. This data is collected and stored in the memory (EPROM - erasable programmable read-only memory) located in the tag.

The key advantage of the passive type is the low cost of the tags and the possibility of very small sizes. Consequently, you can often find them inside a payment or access card, as well as embedded into security or process control labels.

The “active” tag system comprises tags with their own power supply. The key advantage of this type is the longer range of up to 10m instead of typically 10cms for the passive type. The range is limited by the signal strength and the ability to recover signals from any noise picked up from the reader. To help rectify this, active RFID systems often include additional noise filtering techniques such as Frequency Shift Keying (FSK) or Phase Shift Keying (PSK).

Also, the tags in the active type systems create a variable load on the reader antenna. This change in load can be detected by the reader receiver. This is how the tag responds. A common frequency for RFID is high frequency (HF) at 13.56MHz. Also, low frequency (LF) at 125kHz or 134kHz, and Ultra-high frequency (UHF) at 840 to 940MHz.

Where are RFID systems used?

RFID systems include object identification or tracking. The objects can be anything that you want to identify or track. The RFID systems can be found in several market segments including security and access, retail, industrial, healthcare, transport logistics, agriculture, farming, and commercial.

Identification Applications

• Typical identification applications include contactless payment, building access, vehicle access and recording the race time of running participants, and pet tracking, corresponding to the identification of each of these objects.
• The benefits to the end-user are typically improvements in security and ease of use whether it is easier to make payment, enter a car park/worksite, or identify livestock.

Tracking Applications

• Typical tracking applications include tracking of assets, industrial items, hospital equipment, library books, warehouse inventory, and clothing.
• The benefits to the end-user include improved security of high-value items; making sure they remain onsite or store, improved logistics of industrial equipment and being able to find and use hospital equipment in a shorter time, and improvements in production efficiency.

What is NFC?

Near-Field Communication (NFC) is a global industry standard that utilizes RFID technology. NFC builds on RFID technology operating at 13.56 MHz for very short-range (e.g., 0.2m). Data is stored in an EPROM on the NFC integrated circuit (IC). This can be read or written with the option to add security if needed.

There are three “modes” of NFC tag, NFC reader/writer, peer-to-peer (e.g., between two devices), and card emulation mode (e.g., contactless payment).

NFC technology goes beyond RFID with this additional functionality and has been integrated into the latest Smart Phones allowing the phone to be used for either contactless payment or other NFC communication applications. This adoption has helped to make NFC more widely known, with NFC labels being located on products or advertisement points for quick access to information about a product or service.

Typical RFID Applications

• Contactless payment
• Access Control
• Asset tracking
• Garage door openers
• Keyless Entry for vehicles
• Wild animal tracking

Typical NFC Applications

• Contactless Payment
• Software updates via NFC and Smart Phones.
• Tap for info. labels

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