The Definitive Manual to Active RFID Tags

Imagine a world where you can gain real-time data on the whereabouts of mundane objects. Well, this is precisely the world brought about by active RFID tags. Over the last decade, the utilization of RFID technology has proliferated tremendously because of its convenience and precision in object monitoring and interaction. It is a technology that has tremendously eased object tracking and enhanced real-time communication.

In this piece, we dissect active RFID tags, with the aim of helping you grasp how to utilize them optimally.

Figure 1 Active RFID tag.

What Are Active RFID Tags?

Active RFID tags are high-tech gadgets with self-powering capabilities and they are designed to rack up information and broadcast it to connected readers for comprehension. Their composition constitutes an internal battery and this has the benefit of uninterrupted signals transmission. Even in the absence of RFID readers. Additionally, the onboard battery equips active RFID tags with the capability to execute more tasks than passive RFID tags. For instance, active tags can partake in extra functionalities like sensor monitoring while facilitating long-range communication.

Active RFID Tags Functions.

Owing to their self-sufficiency, reliability, and scalability, active RFID tags are ideal solutions for multiple tasks. Underneath, we delve deeper into the most renowned functions of active RFID tags.

● Identification and Tracking.

The broadcasted information, which is continuously amassed by active RFID tags can contain identification details or real-time location status. Active tags can distinguish and locate people, assets, or even mundane objects. A good example is implanting active RFID tags on products of interest to grant authorized personnel like a warehouse manager the latest data on the items—for instance, their placement, movement, or condition.

● Sensor Data Collection.

Active RFID tags are capable of carrying out advanced functions other than identification and monitoring. They can be supplemented with sensors to partake in secondary functions such as temperature monitoring. For example, perishable products held in cold storage can be fitted with active RFID tags to give the supervisors real-time readings of the product’s temperature. This can help handlers mitigate perishability.

Figure 2 Active RFID tag with temperature sensor.

● Access Control.

One of the most utilized functionalities of active RFID tags is moderating entry to secluded or no-access areas. For instance, in a hospital, doctors and authorized hospital staff can be granted active RFID tags that can be used as gate passes for restricted areas. The active tags can broadcast the owners’ unique identification codes to linked scanners, located at entry points, consequently granting them access.

● Personnel Safety.

Certain working environments are unpredictable and quite reasonably unsafe. In such environments, active RFID tags can come in handy. Operations such as mining can overcome the threat of staff disengagement and object misplacement by utilizing active RFID tags. The tags grant site supervisors real-time details on their respective workers’ whereabouts as well as the condition of their assigned equipment. This can aid greatly in rescue operations in the event of a disconnect or emergency situation.

● Alert Systems.

Alert or alarm systems are great security enhancement measures. Incorporating RFID technology into alarm systems complements their functionality thereby enhancing their usefulness. For instance, theft of valuable items in an organization can be averted by tagging the items with active RFID tags. These tags can trigger the alarm system once movement beyond authorized regions is detected.

The Inner Workings of Active RFID Tags.

The working principle of RFID communication is founded on electromagnetic fields. The fields facilitate the exchange of data between active RFID tags and their respective RFID scanners. They employ working principles that are slightly different from those employed by passive RFID readers as shown underneath.

● Tag Activation.

To perform their functions, they are implanted on an object or person of interest and whenever the tagged object nears an assigned reader, the active RFID tag is activated. This is prompted by the reception of the signals discharged by the nearby reader. After sensing the signal, the tag’s integrated circuit activates the microcontroller.

● Data Transmission.

After activation, the active RFID tag is now ready to run. The gathered data is encoded by the microcontroller into radio frequency signals before being modulated onto the carrier frequency. The tag’s transceiver is responsible for data transmission to the RFID reader.

Figure 3 Active RFID tag data transmission.

● Reader Reception.

After the active RFID tag has dispatched a signal, the signal is picked up by a specific reader that is nearby. Signal reception is a role preserved for the antenna attached to the RFID reader. It then sends this signal to another part of the reader called the receiver module, which converts the signal back into its original form.

● Data Processing.

The received signal must be demodulated before being relayed to the RFID reader’s microcontroller for processing. During this process, the signals are decoded and the sent information is extracted.

● Response Generation.

Once the RFID reader processes the received data using the microcontroller, it generates a response. In its response, the reader may roll out commands to the RFID tag or send an acknowledgment note.

● Tag Response.

To effectively complete the communication the antenna on the active RFID tag picks up the response dispatched by the respective interrogator. The microcontroller decodes the reply and starts implementing the communicated command.

The Architecture of Active RFID Tags.

Despite being small in size, active RFID tags consist of numerous constituents with each constituent assigned a distinct role. In the following section, we focus our discussion on the primary components that make up a functional active RFID tag.

● Microcontroller.

The microcontroller is ideally the tag’s principal constituent and it runs the most significant tasks of the tag. It oversees communication with auxiliary hardware such as the RFID reader and it practically controls all tag operations.

● Power Source.

Some of the batteries employed to boot active RFID tags include lithium batteries, which are small and quite powerful.  These batteries help the tags to operate on their own. The on-board batteries power their functions meaning they do not have to rely on RFID readers for energy.

● Antenna.

RFID tag antennas are relatively big sized and they are responsible for signal reception. Tag antennas can be designed differently to accommodate different sizes and shapes. They can also be internal or external.

Figure 4 Active RFID tag components.

● Substrate.

The substrate is an important part of a tag because it keeps everything together. It is usually made of flexible material like thin plastic, but it can also be stiff. The tag antenna is put on the substrate using a special process, and the IC is connected to the antenna. The substrate does many things: it stops static electricity, gives a flat surface for the antenna, makes everything strong and safe, and protects the antenna, chip, and their connections.

● Tag Enclosure.

The active RFID tag enclosure is a strong casing that houses the tag’s primary components. It provides protection from physical forces as well as substances like water, dust, and particulates.

Active RFID Tags Categories.

Active RFID tags are divided into two categories:

● Transponders.

Transponders are principally used for identification and communication purposes. They operate by responding to specific requests or queries from RFID readers or interrogators. A Transponder acquires signals emitted by RFID scanners, then figures out the contained command and responds to the scanner.

● Beacons.

They operate differently from transponders. Rather than responding to queries from readers, beacons continuously transmit their unique identifier or other predefined information at regular intervals. This continuous transmission makes beacons useful for proximity-based applications, where the presence or location of an object or person needs to be constantly monitored.

Pros and Cons of Active RFID Tags.

Today, you will find active RFID tags being exploited differently in virtually all industries. This is primarily because they have proven to be handy tools with a myriad of high-rewarding pros. However, they also have their fair share of drawbacks as is with any type of technology. Beneath, we evaluate the varying benefits and challenges of active RFID tags with the intention of aiding you make better decisions when it comes to RFID adoption and implementation.

Pros.

1. Broader Read Range.

With active RFID tags, you can transmit signals to a linked reader out of sight. They support read ranges of over 100 meters and the distance hardly impacts the signal quality. Moreover, the strength of the emitted signal can surpass obstacles. These tags utilize the 433 MHz range, which makes them effective even in environments with significant hurdles. This makes them exemplary options for operations that necessitate long-distance object monitoring.

2. Continuous Transmission.

This feature proves invaluable for users seeking to have up-to-date updates on tagged objects. For instance, logistics and inventory managers can streamline their operations with active RFID tags by exploiting their continuous broadcasting feature

Figure 5 Long-range RFID reader.

3. Enhanced Data Storage.

Active RFID tags possess built-in memory chips with storage capacities as high as several megabytes. As such, they can retain amassed data internally thereby qualifying their deployment in complex operations. In addition to storing larger amounts of information, they can also retain various data types including timestamps and sensor readings.

4. Advanced Functionality.

The engineering of active RFID tags equips them with the capability to initiate more complex functions. For instance, they can be modified to provide valuable insight into environmental parameters like humidity and temperature. This level of scalability makes them ideal solution providers for complex industries like healthcare and cold chain management.

Cons.

● Limited Battery Life.

The in-built battery is susceptible to depletion, upon which, the active RFID tag shuts down and seizes operations. Battery life is influenced by multiple factors such as the broadcasting range and the level of usage. To overcome this challenge, battery replacement or recharging is necessitated once in a while.

● Relative Higher Costs.

The sophistication of active RFID tags often translates into relatively higher prices. For instance, the cost of long-life batteries and attached sensors is taken into count during pricing. However, this is not necessarily a disadvantage, given that the additional components bring about advanced functionality and convenience.

How to Successfully Utilize Active RFID Tags.

Adopting and successfully implementing active RFID technology can seem like an uphill task but by following the following practices, you will find it relatively straightforward.

● Conduct a Site Survey.

Understand the layout, architecture, and environment where the active RFID tags will be deployed. Identify potential interference sources such as metal structures, dense walls, or other devices that could hinder the RFID signals. By assessing the site beforehand, you can plan tag placement and optimize reader positioning for maximum coverage and performance.

● Active RFID Tag selection.

Having discussed transponders and beacons, I believe you have a better understanding of their ideal use scenarios. Look for tags that meet your specific requirements in terms of range, battery life, and environmental durability. Different tags have varying capabilities, so choose the ones that align with your deployment goals. Also consider factors such as the operating frequency, power output, and compatibility with existing systems.

● Set up Robust Communication Infrastructure.

Active RFID tags require a reliable network to transmit data between the tags and the readers. Ensure that you have a well-designed and properly implemented network infrastructure to handle the data flow. Consider factors like network capacity, coverage, and security to ensure seamless communication.

Figure 6 Active RFID system.

● Proper Installation.

Proper installation ensures optimal performance and longevity of the tags. Follow manufacturer guidelines and best practices for tag attachment, taking into account the specific asset or application. Keep in mind factors such as tag orientation, attachment method, and any environmental factors that may impact tag performance.

● Pilot Tests.

Conduct pilot tests to evaluate the performance of the active RFID system in a real-world scenario. Test various aspects such as tag readability, range, and data accuracy. Additionally, validate the system against your intended use cases and make any necessary adjustments before moving forward.

● Training.

Throughout the deployment process, communication and training are key. Ensure that all stakeholders, including employees, are well-informed about the active RFID deployment. Provide training on how to use and interact with the system effectively. This will help in minimizing errors and maximize the benefits of the technology.

● Maintenance Plan.

Lastly, maintain an ongoing monitoring and maintenance plan. Regularly assess the performance of the active RFID system and address any issues promptly. Conduct periodic system checks, battery replacements, and firmware updates to ensure continued reliability and accuracy.

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