RFID (Radio Frequency Identification) technology utilises radio waves to transmit data about an object using radio waves, used in supply chain management and asset tracking applications.
An RFID reader is a device that decodes information contained within an RFID tag. It may be handheld, mounted to a cart or vehicle, or permanently installed at a location.
Detection Methods
Various detection methods are available for RFID readers, which will work best depending on several variables. First and foremost, consider your coverage area requirements and which tags you are using.
Next, you must consider what type of environmental conditions will impact your system. These could include metal particles, liquids or other substances that impede its read range or accuracy.
Once your system has been designed and assembled, consider its intended usage. For example, will it need to remain stationary or require mobility?
Once you have decided upon a detection method suitable for your RFID reader, you must test its technology on tagged items before investing in an expensive reader. Doing this ensures it works in your environment before investing further in expensive technology.
Suppose you use an RFID reader for inventory applications, such as inventory tracking or control. In that case, it must be tested against scanned assets to ensure its effectiveness and efficiency. In addition, test different tag types to ensure that the chosen one works in your environment.
Interference can also hinder the accuracy of an RFID system. Metal and liquid materials, for instance, may interfere with its signals, leading to shorter read ranges and reduced accuracy. However, various techniques are designed to counter these problems and tags are explicitly designed to combat interference for increased precision of your system.
Detection Range
RFID technology uses radio waves to transmit data between tags and readers, with both elements needing to be within an acceptable detection range to work successfully.
An RFID reader’s detection range depends on several factors beyond just its frequency type; these include power consumption, cable length and sensitivity settings.
Longer cables decrease signal strength between the reader and antenna, so shorter ones should be chosen to increase the read range. Also, consider investing in higher-rated insulated cable to prevent energy loss and keep more power going to antennas.
The detection range can also depend on the types of tags and their orientation. Regarding single orientation tags, linear-polarised antennas work best; circular-polarised antennas are ideal for those that can read multiple orientation tags more effectively.
Active tags have longer read ranges than passive ones because their signals can travel further. For example, low-frequency or LF tags can reach 30 cm (1 foot), while high-frequency tags may extend as far as 50 feet.
RFID tags that fit inside microchips (0.05 mm x 0.05 mm) have been successfully used on everything from live ants to laptops. Even though these tiny tags may appear fragile, they still transmit strong signals and provide accurate location data.
The more extended range doesn’t always translate to greater detection frequency; rather, it indicates that your tag can pick up weaker signals at greater distances. That being said, you must select the ideal tag for your application and understand its maximum range.
Detection Speed
RFID readers offer significant advantages when used for preventative maintenance and safety applications. With their rapid scanning speed, RFID readers can quickly detect tags – often less than one millisecond – bringing significant time-savings.
Two primary factors impact the speed of an RFID reader in terms of detection speed: expected tag responses per request and available memory capacity for reading tags.
The second factor is the frequency of tag responses. As frequency increases, so too will the reader speed at reading tags.
Low frequencies cause the reader to identify fewer tags, potentially degrading system performance if its frequency shifts or is insufficient for its purpose.
Another critical consideration regarding RFID tag and antenna placement is orientation; when aligned correctly, its range increases dramatically – this phenomenon is known as “read angle.”
An RFID tag placed on the ground may move in various directions, and this could significantly decrease its range.
Finally, cable length can hurt its range; the longer a cable is, the more energy will be lost to frictional resistance and dissipation.
To optimise RFID reader detection speeds, consider using shorter cables without adapters or multiplexers that add extra losses; high-rated, insulated cables are best to counterbalance any losses from reduced detection speeds.