Active, Passive, and Semi-Passive RFID Tags: How to Choose?
How to Choose Between Active, Passive, and Semi-Passive RFID Tags
For decades, radio frequency identification (RFID) tags have introduced item-level visibility and control in inventory management, supply chain and logistics, security, asset tracking, and other RFID applications.
The different types of RFID systems and tags’ attributes make them ideal solutions for varying applications.
The most important difference between RFID tags is the way tags and readers communicate. The three main classifications include active, semi-passive, and passive RFID tags (also called battery-assisted passive tags).
What’s the difference between active, passive, and active/passive hybrid RFID tags?
How might the differences make one type of RFID system more favorable for your needs?
Here, we’ll take a brief look at the differences in these RFID technologies, and the ranges of environments and applications where they’re typically used — because the first key to getting optimal results from your RFID system is choosing the right combination of technologies in the first place.
Active RFID Tags
Active RFID tags incorporate a transmitter (either a transponder or a beacon) and a battery as a power source, built together into a single unit. The battery powers the transmitter as it sends data to an RFID reader. They can either transmit continuously (beacons) or when activated by a reader’s radio signal (transponders). Active RFID tags are usually smaller than a smartphone, and are often built in a rugged, protective casing that can be riveted, zip tied, screw-mounted or even welded to objects.
Active tags are most often used for large-scale applications that call for tags that can be read over greater distances, as in construction, oil and gas, mining, and other industrial and logistics applications. They most often transmit data in higher frequency ranges (850-950 MHz is common), and the tags can often be read from a distance of 100 feet and more — and at higher speeds, as in electronic toll collection.
Active tags are typically larger in size, have greater data capabilities, and can include environmental sensors that collect temperature, moisture, and other data to help protect high-value and sensitive assets. Among the most important advantages of active tags are:
- Longer read ranges
- Significant data memory
- Integration with other asset-control and geolocation technologies
- Availability of rugged and weather-resistant housings
Among active tags’ limiting attributes are their higher cost, limited battery life (usually 3 to 5 years), and larger size. Even so, when used to track and protect high-value assets, active RFID systems’ ROI can be significant. Active transmitters can also add another source of noise to work environments.
Semi-Passive, or Battery-Assisted Passive, RFID Tags
In between active and passive RFID tags are semi-passive tags, or battery-assisted passive RFID tags.
Semi-passive RFID tags look more like passive tags in terms of size and ease of manufacture, but like active tags, they incorporate a power source — usually a small, eco-friendly battery — to improve data transmission. The end result is a tag that offers many of the benefits of active RFID tags, but at a price point that’s closer to a passive tag. Advantages include:
- Can support some sensors and memory functions
- Medium-distance reading — longer range than passive tags
- Lower cost than active tags
Like active tags, hybrid RFID tags are limited by battery life.
Passive RFID Tags
As the name suggests, passive RFID tags rely on the tag reader to supply power electromagnetically. For this reason, tags are typically readable from about 20 feet away or closer, and passive tags are more often used in smaller-scale applications and RFID inventory systems.
Because they don’t include their own power source, some of the advantages of passive RFID tags can include:
- Greater range of shapes, sizes, and materials (both inlays and hard tags)
- Lower cost per tag
- Embeddable formats that can fit into almost any product or packaging
- Potentially longer operational life, since no power source is needed
Passive RFID tags and readers are often used in item-level tracking applications, labels, IT hardware, document controls, medical facilities, and wristband or badge access controls.
Bonus Option: Bluetooth Low Energy (BLE)
Compared to RFID systems, BLE is relatively new. Most people are familiar with Bluetooth technology as it’s used for internet-connected devices to communicate, like wireless headphones, speakers, and other peripherals. BLE systems use Bluetooth communication to operate like active RFID systems, “beaconing” from tags to readers that transmit data to the cloud.
BLE offers an inexpensive, scalable solution for many simpler use cases that typically involve sensors. BLE technology allows for development of monitoring dashboards for things like equipment performance, maintenance, and ERP systems in manufacturing environments, or a variety of applications that fall within the Internet of Things (IoT).
Major Considerations When Choosing an RFID System
Global RFID users in nearly every industry from retail to healthcare benefit from the item-level visibility and control the technology offers, to reduce overall costs, improve responsiveness, increase efficiencies, and lead within their industries.
Choosing the best combination of RFID system technologies and components requires a balance of potential advantages and drawbacks like size, cost, product lifespan, system integrations, and much more. The choices of RFID tag and reader types can make almost any configuration possible — but to get the most from your RFID system from day one, it’s crucial to partner with an expert.
An experienced team starts the evaluation process with a consideration of your needs:
- Industry, challenge, working environment
- Information needs
- Transmission range
- Tag size and flexibility
- Costs of tags, readers, and peripheral hardware
- Integration capabilities
- And more
With a focus on your needs, your process, and your users — the people who’ll interact with your system minute-to-minute — RFID experts will guide you to the right technologies and systems to achieve your goals, protect your assets, and safeguard your business.
If you’re weighing the pros and cons of the different RFID system types, or you’re looking for more information, we welcome your inquiries via our contact form, email, or phone call. We’re confident you’ll be glad you reached out.