RFID Theory

The RFID system typically consists of a tag made up of a microchip with an antenna, and an interrogator (reader), which is embedded with a single chip processor and an antenna.
The purpose of an RFID system is to enable data to be transmitted by a tag, which is read by an RFID reader and processed according to the needs of an application. Moreover, the data transmitted by the tag may provide identification or location information, or specifics about the product, for example, price, color, date code, etc. Also, RFID systems can be employed for tracking objects- as an invasion of privacy.

In short, RFID tags can carry data and serve as data transfer agents; a reader in range of the tag’s signal will receive the data, decrypt it, and forward it to the host computer for stores all collected data within a database.

What is RFID Reader?

Basic function of the RFID reader is to converse with the RFID tag by originating radio waves from its antenna.
The RFID readers are classified on their variety, such as Microwave frequency, UHF (Ultra-high frequency), HF (High frequency) and LF (Low frequency) that are 5.8 GHz to 125 KHz. There costs are also reliant on their range; Microwave frequency readers are costliest, LF readers are the cheapest.

Mainly, there are two types of RFID reader: handhold and fixed.

Handhold Type Reader

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The Handheld reader fits comfortably in the palm of your hand. Users carry this portable Reader while looking for specific items such as merchandise, inventory, or other assets.
The Handheld reader not only can be used to manually scan but also program individual tags. Instead of reading all tags in an area at one time, users can selectively read and program only particular items.

Fixed Type Reader

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The fixed reader is an RFID interrogator mounted to a permanent or non-mobile structure enabling users to read RFID tag numbers attached to movable items.

Benefits and Characteristics of RFID

Nowadays, RFID is already having a significant impact on many businesses.
RFID can deliver benefits in many areas from tracking work in progress to speeding up throughput in a warehouse and so on.

Here is the list of RFID benefits and features.
* RFID (Tag) can be read from a distance and from any orientation
* RFID(Tag) do not require line of sight to read
* RFID (Tag) have both read and write capabilities
* RFID (Tag) Can provide large amounts of data
* RFID (Tag) can be embedded easily into different objects
* RFID (Tag) can read at rapid rates- at a speed of up to 1,000 tags per second
* RFID (Tag) can be read in harsh environments where operating temperatures range from 22 degree Fahrenheit to +159 degree Fahrenheit
* RFID (Tag) is costly but efficient
* RFID (Tag) do not get damaged easily
* RFID system offers permanent identification- tags encrypt information with unique identification
* RFID reduces administrative error, labor costs associated with scanning, reading and shipping
* RFID improves businesses and guarantee traceability
* RFID can help to improve the forecasting

Why Choose a Passive RFID Tag?

A passive RFID tag is normally used in applications such as access control, item tracking, race timing, supply chain management, logistics, ticketing, cashless payments and more. The low price point per tag makes passive RFID tags economical and the short to medium read ranges are well-suited to applications where you need to read one RFID tag at a time rather than many tags at once.

Because passive RFID tags have no battery, the tag form factor tends to be smaller and inexpensive to deploy. Passive RFID tags also come in many different form factors, from RFID bracelets and key fobs to RFID smart labels and cable tags. The various sizes and form factors lend themselves to a range of RFID applications and the lack of battery means that the tags can operate for many years without the need for battery replacements or other staff support.

Despite its many advantages, you should also consider some of these disadvantages when choosing a passive RFID tag:

Passive RFID tags can be read at short distances, typically 6 cm to 30 cm. This creates reading limits for certain types of RFID applications.
Improper RFID tag antenna orientation towards the reader in some types of passive RFID tag applications can result in unstable reads.
Limited memory for data storage.
Reading through liquid or metal can be difficult for some types of passive RFID tags.

Typical Applications for Passive RFID Tags:
Consumer Goods Tracking
Small Item & Asset tracking
Ticketing & Payments
Vehicle Identification
Inventory Management
Access Control Applications
Rapid Transit Ticketing
Supply chain management
Work-in-process Tracking
Production Line Management
Race Timing Applications
Parking Lot Access Control
Festivals and Marketing Events

What is the Distance/Range of RFID Tags?

RFID reading distance depends on several factors including:
* Size of the tag’s antenna
* Tag chip
* Tags orientation in the reader field
* Strength of the reader field
* Environmental factors like metal, water or other material around the tag
* LF, HF and UHF near-field tags typically have a reading distance of ~1 ft (30 cm).
* UHF far-field tags typically have a reading distance of several m/ft but are strongly dependent on the environment.
* NFC Tags (HF) are designed for near-field communication with a smartphone or similar device and typically have a reading distance of ~1 in (2 cm).

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