An RFID tag uses radio waves to identify a particular object. The tags are available in two main types: active and passive. Passive tags do not require a power source. They only need an antenna and an integrated circuit. They are typically inexpensive and small. Passive RFID tags use an antenna to communicate with a reader.
Active RFID tags
Active RFID tags are tags that transmit information via a radio frequency, usually at 433 or 915 MHz. They typically include a tag, antenna, and interrogator. Battery-operated active RFID tags can have a battery life of up to 5 years, depending on the size and power requirements. Beacons emit a ping every few seconds and can be read from hundreds of feet away. The downside of beacons is that they have a shorter battery life than transponders.
To address the issue of tag reuse, the Undersecretary of Defense for Acquisition, Technology, and Logistics should amend the current operational guidance to include a requirement for military services to return active RFID tags after use. The new regulation should specify how active RFID tags can be used by military services and other users.
Semi-passive RFID tags
Semi-passive RFID tags do not transmit a periodic signal but rather wait for a signal from a reader. This helps improve the read range and transmission speed of the tag. Semi-passive tags are an economical option for RFID tracking systems. They can also be used for environmental and condition monitoring.
Semi-passive RFID tags can also detect moisture and temperature. These sensors are available in various forms, including a low-cost UHF version called A927ZH. They can record up to 4.000 temperature samples and have an operating temperature range of -20degC to +70degC. The tags can also generate alarms based on the readings.
Battery-operated RFID tags
Battery-operated RFID tags are one of the many types of RFID tags. They have several advantages over passive RFID tags. Passive tags are not powered by batteries, but rather by the reader’s power. Unlike passive RFID tags, battery-operated RFID tags can operate for a long time without any battery replacement.
Active RFID tags transmit information using the radio frequency (RF) or near-infrared (NIR) spectrum. They contain a tag, antenna, and interrogator. An active tag’s battery should last three to five years. Active RFID tags may also use autonomous networking, which determines the best path for communication. However, these tags can be more expensive, because they require a reader for power.
Capacitively coupled RFID tags
Capacitively coupled RFID tags are a form of RFID tags that uses a power scheme that allows the tags to be powered by external power. The tags are typically low-cost, and the reading range is very long. The capacitively coupled RFID tags are also referred to as passive RFID tags.
Capacitively coupled RFID tags typically cost less than inductively coupled RFID tags. This is because the tags don’t use a coil antenna and use silicon circuitry instead. The tag typically includes a silicon microprocessor and conductive carbon ink. The conductive carbon ink serves as the tag antenna and is applied to a paper substrate.