Introduce

Welcome to the Beginner's Guide to RFID Systems! This guide is ideal for those who are new to RFID and want to understand what RFID is, how RFID is used, the different types of RFID, and how to build an RFID system.

Contents

• Introduction

• What is RFID?

• Important facts

• RFID tags

• RFID reader

• RFID antenna

• Kits and additional items

• Next

What is radio frequency identification?

Radio Frequency Identification (RFID) is a wireless, non-contact use of radio frequency waves to transmit data. RFID systems usually include RFID readers, RFID tags, and antennas.

How does RFID work?

Using RFID tags to tag items allows users to automatically and uniquely identify and track inventory and assets. RFID takes automatic identification technology to a new level, allowing tags to be read without a line of sight, and depending on the type of RFID, the reading range ranges from a few centimeters to more than 20 meters.

RFID has made great progress since it was the first time to identify an aircraft as an enemy or friend in World War II. Not only has technology been continuously improved year by year, but the cost of implementing and using RFID systems has been continuously reduced, making RFID more cost-effective and efficient.

Types of RFID

In the electromagnetic spectrum, there are three main frequency ranges used for RFID transmission-low frequency, high frequency, and ultra high frequency.

Low frequency

General frequency range: 30-300 kHz

Main frequency range: 125-134 kHz

Reading range: contact-10 cm

Average cost per label: $0.75-$5.00

Applications: Animal tracking, access control, car key fobs, large amounts of liquid and metal applications

Advantages: applicable to liquids and metals, global standards

Disadvantages: the read range is very short, the amount of memory is limited, the data transmission rate is low, and the production cost is high

High frequency

General frequency range: 13.56 MHz

Reading range: close contact-30 cm

Average cost per label: $0.20-$10.00

Applications: DVD kiosks, library books, personal ID cards, poker/game chips, NFC applications

Advantages: NFC global agreement, larger memory options, global standards

Disadvantages: short reading range, low data transmission rate

UHF

General frequency range: 300-3000 MHz

Main frequency range: 433 MHz, 860-960 MHz

There are two types of RFID in the UHF range: active RFID and passive RFID.

Active RFID

Main frequency range: 433 MHz, (2.45 GHz can be used-in the extremely high frequency range)

Reading range: 30-100+ meters

Average cost per label: $25.00-$50.00

Applications: Vehicle tracking, automobile manufacturing, mining, construction, asset tracking

Advantages: long reading range, low infrastructure cost (compared to passive RFID), large memory capacity, high data transmission rate

Disadvantages: high cost per label, transportation restrictions (due to batteries), complex software may be required, high interference from metals and liquids; few global standards

Passive radio frequency identification

Main frequency range: 860-960 MHz

Reading range: close contact-25 meters

Average cost per label: $0.09-$20.00

Applications: Supply chain tracking, manufacturing, pharmaceuticals, electronic toll collection, inventory tracking, game timing, asset tracking

Advantages: long reading distance, low cost per tag, various tag sizes and shapes, global standards, high data transmission rate

Disadvantages: high equipment cost, moderate memory capacity, large interference from metals and liquids

Major subset of passive RFID

The relatively wide 860-960 MHz range is recognized as the "global standard" for UHF passive RFID; however, its later adoption has resulted in the range being further divided into two main subsets-865-868 MHz and 902-928 MHz .

865-868 MHz-ETSI

The European Telecommunications Standards Institute (ETSI) is the European regulatory agency responsible for the development and maintenance of national standards for communications over multiple channels (including radio waves). According to ETSI regulations, RFID devices and tags are only allowed to communicate in the smaller frequency range of 865-868 MHz, because other types of radio communication are allocated to a subset of the larger range of 860-960 MHz.

Because ETSI has established a standard for Europe, but when buying labels and equipment, the standard can be called ETSI or EU, which means Europe.

902-928 MHz-FCC

The Federal Communications Commission (FCC) is the regulatory agency in the United States responsible for establishing and maintaining national standards for communications through multiple channels, including radio waves. FCC regulations stipulate that RFID tags and devices can only operate between 902-928 MHz, because like Europe, other communication types are allocated to the rest of the larger range of 860-960 MHz.

RFID devices or tags that have passed FCC certification or are in the North American frequency range or NA can be used throughout North America.

Other

Since ETSI and FCC were both the first major standards to be approved, many countries will either adopt one of them or create their own standards in a subset of any frequency range*. For example, Argentina chose to use the FCC's 902 – 928 MHz range, while Armenia chose to implement its own smaller frequency band 865.6 – 867.6 MHz within the ETSI range.

Although regional regulations such as FCC and ETSI usually use frequency ranges for discussion, each country has other specific regulations, such as radiated power (ERP or EIRP). Some countries/regions are more stringent and stipulate where RFID can be used, the amount of "frequency hopping" that must be used, or the use of RFID requires a license. For more information on regulations in each country-read "How to comply with regional regulations when using RFID."

RFID application example

There are countless examples of applications that benefit from RFID. The application extends from a wide range of areas such as inventory tracking to supply chain management, and can become more professional depending on the company or industry. The types of RFID applications can range from IT asset tracking to textile tracking, and even details such as tracking leased items.

What distinguishes potential RFID applications from applications that can use other types of systems is the need to uniquely identify individual items quickly and more efficiently, which traditional systems cannot do. The following are some applications that have successfully used RFID technology.

• Competing time

• Supply Chain Management

• Drug tracking

• Inventory tracking

• IT asset tracking

• Laundry and textile tracking

• Document tracking

• Returnable Transit Items (RTI) Tracking

• Event and attendee tracking

• Access control

• Vehicle tracking

• toll

• Hospital baby tracking

• Animal tracking

• Tool tracking

• Jewelry tracking

• Retail inventory tracking

• Pipe and spool tracking

• Logistics tracking (material management)

• DVD kiosk

• Library data tracking

• Marketing activities

• Real-time positioning system

• Important RFID facts

• Return on investment (ROI)

  
  

When considering the purchase and deployment of any new system, the two most important questions that need to be answered are whether and when the company will see a return on investment. Before implementing a new system, it is necessary to evaluate the conversion costs in terms of fixed costs, recurring costs, and labor costs.

Before implementing an RFID system, the application feasibility and cost feasibility should be evaluated.

Application feasibility

Application feasibility refers to the process of determining whether an application is suitable for use with RFID. Like all technologies, RFID has limitations. Environmental restrictions, read range restrictions, and asset material composition are just a few different aspects that can severely affect the effectiveness of RFID systems in specific applications. The application feasibility process should start with the project scope and project environment, and then determine whether RFID (or other technology) is suitable for application.

Cost feasibility

Cost feasibility refers to evaluating whether an RFID system can be implemented from a monetary point of view. Cost feasibility includes not only whether the rate of return on investment is possible, but also the use of current and expected figures to determine the estimated timetable for return on investment. RFID systems can be expensive. They need an initial investment to test and use different types of equipment and tags (if the technology is not successful, this may be a sunk cost for the company). After the testing phase, deployment costs begin (read more about fixed and recurring costs below). Only after the system is implemented and operating normally can you begin to see the timetable for the return on investment.

Fixed costs and recurring costs

Grouping costs by fixed (initial) or recurring will help to more accurately portray the expected annual cost and return on investment of the system.

Fixed cost

Fixed costs are one-time costs associated with getting started. In RFID deployment, fixed costs are usually related to hardware such as readers, antennas, and cables required to set up the system. The fixed cost does not necessarily mean that you will never buy the item again, it just means that the item will not be used once and then discarded or consumed during the application period. If you plan to build an initial system and then expand that system later, the hardware will still be considered a fixed cost. RFID tags are considered a fixed cost only when they are repeatedly used throughout the system-such as access control RFID keys that are allocated and re-allocated to employees as needed.

Recurring cost

Recurring costs are attributed to items that are used once and then discarded or consumed during the application process. RFID inlays or tags are common examples of recurring costs in RFID systems. Due to the low cost, these labels are often affixed once and kept for the entire life cycle of the item (or discarded after use). If an RFID printer is used, the printer ribbon is also a recurring cost. If the software license is updated annually or purchased as a SaaS (software as a service) product, then it should also be included in recurring costs.

Envirnmental factor

RFID systems may be susceptible to certain materials and environmental factors, which will reduce the reading range and affect the accuracy of the overall system. Metals and liquids are the two most common sources of interference in RFID applications, but their impact can be mitigated by appropriate RFID tags, equipment, and planning.

As UHF RFID becomes more and more commonly used for liquid-filled items or metal items, more and more tags are released in new ways to reduce these problems. In addition, technologies have been developed that can help mitigate the impact of these projects, such as the use of label placement and spacers.

What is an RFID system?

Although each system will be different in terms of equipment type and complexity, each RFID system contains at least the following four components:

• Reader

• Antenna

• Label

• Cable

  
  

The simplest RFID system can consist of a mobile handheld RFID reader (with integrated antenna) and an RFID tag, while more complex systems use multi-port readers, GPIO boxes, additional functional devices (such as stacked lights), and multiple antennas And cables, RFID tags and complete software settings.

RFID Tags

What is an RFID tag?

The simplest form of RFID tag consists of two parts-an antenna for sending and receiving signals, and an RFID chip (or integrated circuit, IC) that stores the tag ID and other information. RFID tags are attached to items so that they can be tracked using RFID readers and antennas.

RFID tags use radio waves to transmit data about items to the antenna/reader combination. RFID tags usually do not have batteries (unless designated as Active or BAP tags); instead, they receive energy from the radio waves generated by the reader. When the tag receives the transmission signal from the reader/antenna, the energy will reach the tag chip through the internal antenna. The energy activates the chip, modulates the energy with the required information, and then transmits the signal back to the antenna/reader.

On each chip, there are four storage banks-EPC, TID, user and reservation. Each of these repositories contains information about the marked item or the label itself, depending on the repository and the specified content.

Hundreds of different RFID tags come in many shapes and sizes, with features and options specific to specific environments, surface materials, and applications.

Learn more about RFID tags-UHF RFID tag guide

Types of RFID tags

Due to the wide variety of RFID applications, there are also various RFID tags and classification methods. Common methods for dividing tags into types are inlays and hard tags. Inlays are cheaper, usually between $0.09 and $1.75, depending on the features on the label. Hard labels are generally stronger and more weather-resistant, with prices ranging from US$1.00 to US$20.00.

Shape-inlays, labels, cards, badges, hard labels

Frequency type – LF, NFC, HF, UHF passive (902 – 928 MHz, 865 – 868 MHz or 865 – 960 MHz), BAP, active

Environmental factors-waterproof, sturdy, temperature-resistant, chemical-resistant

Customizable-shape, size, text, coding

Specific functions/applications-laundry tags, sensor tags, embeddable tags, autoclavable tags, vehicle tags, high memory tags

Specific surface materials-metal installation labels, glass installation labels, liquid-filled article labels

Label pricing

Label pricing depends on the type of label and the quantity ordered. As mentioned earlier, inlays are usually between US$0.09 and US$1.75, and hard tags can fluctuate between US$1.00 and US$20.00. The higher the degree of customization or the more professional the label, the higher its price compared to a typical off-the-shelf label.

Choose RFID tag

• What type of surface will you mark? On metal, plastic, wood, etc.?

• What reading range do you want?

• Size restriction (ie label cannot be larger than x × y × z inches)?

• Do you need to consider excessive environmental conditions? Excessive heat, cold, moisture, impact, etc.?

• Attachment method? Adhesives, epoxy resins, rivets/screws, cable ties, etc.?

• The key to choosing a label is to thoroughly test the various labels in your environment on the actual items you wish to label. The RFID label sample package can be customized for your application so that you can narrow down the range of labels suitable for your application.

RFID reader

What is an RFID reader?

The RFID reader is the brain of the RFID system and is necessary for the operation of any system. Readers, also called interrogators, are devices that send and receive radio waves to communicate with RFID tags. RFID readers are generally divided into two different types-fixed RFID readers and mobile RFID readers. The fixed reader stays in one place, usually installed on a wall, table, entrance, or other fixed location.

A common subset of fixed readers are integrated readers. An integrated RFID reader is a reader with a built-in antenna and usually includes an additional antenna port for connecting an optional external antenna. Integrated readers are usually aesthetically pleasing and are designed for indoor applications without a lot of traffic of marked items.

The mobile reader is a handheld device that has the flexibility to read RFID tags while still communicating with the host or smart device. There are two main categories of mobile RFID readers-readers with on-board computers, called mobile computing devices, and readers that use Bluetooth or auxiliary connection to smart devices or tablets, called Sleds.

Fixed RFID readers usually have external antenna ports, which can be connected anywhere from one additional antenna to up to eight different antennas. By adding a multiplexer, some readers can connect up to 32 RFID antennas. The number of antennas connected to a reader depends on the coverage area required for RFID applications. Some desktop applications, such as checking in and checking out files, require only a small coverage area, so a single antenna can work well. Other applications with greater coverage, such as the finish line in race timing applications, usually require multiple antennas to create the necessary coverage area.

Learn more about RFID readers-Introduction to RFID readers: basic options and features

Types of RFID readers

The most common way to classify readers is to classify them as stationary or mobile. Other ways to distinguish RFID readers include categories such as connectivity, available utilities, functions, processing power, power options, antenna ports, etc.

Frequency range-902 – 928 MHz US, 865 – 868 MHz EU, etc.*

Mobility-fixed reader, integrated reader; mobile reader

Connection options-Wi-Fi, Bluetooth, LAN, serial, USB, auxiliary port

Available utilities-HDMI, GPS, USB, camera, GPS, GPIO, 1D/2D barcode, cellular function

Processing capacity-onboard processing, no onboard processing

Power options-power adapter, PoE, battery, car, USB

Available antenna ports-no external ports, 1 port, 2 ports, 4 ports, 8 ports, 16 ports

Reader pricing

The reader is usually the most expensive component in an RFID system. The price of RFID readers ranges from US$400 to US$3,000 or more, depending on the features and functions required. A cheaper type of card reader is the USB card reader, the average price of which is about US$400. USB readers usually have a short reading range and are used in desktop applications. According to the features and functions provided, the prices of handheld readers and fixed readers vary greatly.

Choose an RFID reader

• What read range does your application need?

• Do you need to consider excessive environmental conditions? Excessive heat, cold, moisture, impact, etc.?

• Will you add the reader to the network?

• Where will readers be placed? Fixed position, or on the vehicle?

• Does the reader need to be moved?

• How many read points/read area do you need?

• How many tags may need to be read at one time?

• How fast does the label move through the reading area? For example, is this a slow-moving conveyor belt or a fast-moving race?

  
  

RFID antenna

What is an RFID antenna?

RFID antennas are an essential element in the RFID system because they convert the signal of the RFID reader into radio frequency waves that can be received by the RFID tag. Without a certain type of RFID antenna, whether integrated or independent, the RFID reader cannot correctly send and receive signals to the RFID tag.

Unlike RFID readers, RFID antennas are dumb devices that receive power directly from the reader. When the energy of the reader is transmitted to the antenna, the antenna will generate a radio frequency field, and then the radio frequency signal will be transmitted to nearby tags. The efficiency of an antenna to generate waves in a specific direction is called antenna gain. In short, the higher the gain, the stronger the RF field of the antenna and the wider the range.

The RFID antenna emits RFID waves along a horizontal or vertical plane, which is described as the polarity of the antenna. If the radio frequency field is a horizontal plane, is it described as horizontal linear? The same principle applies to RFID antennas that create a vertical plane.

The polarity of the antenna will have a significant impact on the reading range of the system. The key to maximizing the read range is to ensure that the polarity of the antenna is consistent with the polarity of the RFID tag. If these do not match, such as a vertical linearly polarized antenna and a tag with a horizontally polarized antenna, the reading range will be severely reduced.

The waves emitted by the circularly polarized antenna continuously rotate between the horizontal and vertical planes in order to enhance the flexibility of the application by allowing the RFID tag to be read in multiple directions. However, because the energy is distributed between the two planes, the reading range of a circularly polarized antenna is shorter than that of a linear antenna with similar gain.

Learn more about RFID antennas-9 strategies for choosing RFID antennas

Antenna type

Like most RFID devices, RFID antennas can be divided into different categories to help narrow the optimal antenna range for applications. Although antennas are grouped by several different factors, the most common groupings for RFID antennas are polarity (circular vs. linear) and robustness (indoor vs. outdoor).

Frequency range – 902 – 928 MHz, 865 – 868 MHz, 860 – 960 MHz

Polarity-circular, linear

Robustness-indoor IP level, outdoor IP level

Reading range-short range (near field), far field

Installation type-shelf antenna, ground antenna, panel antenna, portal antenna

Antenna pricing

The price of most RFID antennas is usually between US$50 and US$300 per antenna, but due to key specific application factors (such as ground/mat antennas), some antennas are more expensive. These antennas are specifically used for applications such as game timing and must be sturdy enough to survive and perform well when people, bicycles or even carts run over them. Dedicated antennas can significantly increase the cost of the system, but it is also an investment, which may be the difference between functional and non-functional systems.

Choosing an RFID antenna

• What read range do you need?

• In your application, can you always know or control the orientation of the RFID tag relative to the antenna position?

• Do you need to consider excessive environmental conditions? Excessive heat, cold, moisture, impact, etc.?

• Is the antenna installed indoors or outdoors?

• Size limitation (that is, the antenna cannot be larger than x × y × z inches)?

Kits and additional items

Development kit

The RFID development kit is a kit usually assembled by reader manufacturers and includes everything needed to start reading and writing RFID tags. The development kit is recommended as the best way to start using RFID technology because it allows people to directly access the technology and start testing their applications. Since these kits are usually manufactured by the reader manufacturer, there are many options to choose from, combining the manufacturer’s reader with the recommended antenna and some sample RFID tags for testing. The development kit usually also includes a sample program for reading and writing RFID tags, as well as access to the manufacturer's software development kit or SDK. The SDK contains documentation on the reader as well as API access and code examples so that software developers can start writing software for applications.

RFID cable

The RFID antenna cable facilitates the communication between the RFID reader and the RFID antenna. If there is no cable, the reader cannot power the tag and send signals through the antenna. Choosing an RFID cable seems easier than choosing other components; however, the cable can vary greatly in three specific ways—connector type, length, and thickness/insulation rating—so, change all three before buying It's important to take everything into consideration.

When determining the correct connectors on both ends of the cable, first look at the connectors on the RFID reader and antenna. For example, if the RFID reader has a RP-TNC female connector, there should be a RP-TNC male connector on one side of the cable, and vice versa. For more information on the different types of cable connectors, please check our RFID cable guide.

The cable length and thickness (also known as insulation class) will vary depending on your specific solution. The length of the cable usually depends on the distance between the RFID reader and the antenna, but it is important to note that the longer the cable, the more power is lost during transmission.

One way to combat power loss is to use higher insulation levels. The longer the cable, the better the insulation that the cable needs to maximize efficiency and reduce the amount of power lost along the length of the cable. It is worth noting that as the insulation level increases, the cable will become thicker and stiffer, which will make it more difficult to bend and use when turning or passing through conduits.

Other equipment and accessories

Some other system accessories and accessories can be used to enhance the function or ease of use of the system. For example, RFID printers, RFID portals, GPIO adapters, antenna mounting brackets, and RF power mappers will all complement or enhance your system.

Next

Although this guide is full of RFID knowledge, it is only the tip of the iceberg for implementing RFID technology. The good news is that we have many different ways to learn more:

RFID Insider-The goal of this blog is to keep you up to date with the latest developments in the RFID industry. Whether you are an industry veteran or a newcomer in the RFD field, we plan to create original content covering a wide range of topics for all levels of RFID expertise.