Passive and active RFID tag

- Jan 06, 2020-

RFID (Radio Frequency Identification), commonly known as "electronic tag", is a non-contact automatic identification technology. It automatically identifies the target object and obtains relevant data through radio frequency signals. The identification does not require manual intervention. The main role is data Write and read. It consists of tags, readers, and data transmission and processing systems. There are two types of electronic tags, active and passive, depending on whether or not a battery is installed.

At present, passive electronic tags account for 80% of the market, and passive electronic tags only account for less than 20%. So what is the difference and connection between active tags and passive tags? Let's take a look with the editor below.

I. Definition

Active rfid, also called active rfid, its operating power is completely supplied by the internal battery. At the same time, some of the battery's energy supply is converted into radio frequency energy required for communication between the electronic tag and the reader. It usually supports long-distance identification.

Passive tags, called passive tags, can receive some microwave signals announced by the card reader, and can convert part of the microwave energy into direct current for their own work. When a passive RFID tag approaches an RFID card reader, the antenna of the passive RFID tag converts the received electromagnetic wave energy into electrical energy, activates the chip in the RFID tag, and sends out the data in the RFID chip. With anti-interference ability, users can customize read and write standard data, which is more efficient in specialized application systems, and the reading distance can reach more than 10 meters.

Working principle

1. Active electronic tag refers to the energy provided by the battery. The battery, memory and antenna together form an active electronic tag. Unlike the passive RF activation method, information is always sent through a set frequency band before the battery is replaced.

2. The performance of passive RFID tags is greatly affected by the tag size, modulation form, circuit Q value, device power consumption, and modulation depth. Passive radio frequency tag 1024bits memory capacity, ultra-wide operating frequency band, which not only meets relevant industry regulations, but also can be flexibly developed and applied, and can read and write multiple tags at the same time. Passive RF tag design, no battery required, memory can be rewritten more than 100,000 times.

Price and service life

1. Active rfid: high price and relatively short battery life.

2, passive rfid: the price is cheaper than active rfid, and the battery life is relatively long.

Fourth, the advantages and disadvantages of the two

1.Active RFID tags

Active RFID tags are powered by a built-in battery, and different tags use different numbers and shapes of batteries.

Advantages: long working distance, the distance between active RFID tags and RFID readers can reach tens of meters, even hundreds of meters.

Disadvantages: large size, high cost, and limited battery life.

2.Passive RFID tags

A passive RFID tag does not contain a battery, and its power is obtained from the RFID reader. When a passive RFID tag approaches an RFID reader, the antenna of the passive RFID tag converts the received electromagnetic wave energy into electrical energy, activates the chip in the RFID tag, and sends out the data in the RFID chip.

Advantages: small size, light weight, low cost, long life, can be made into different shapes such as sheets or hanging buckles, and applied to different environments.

Disadvantages: Because there is no internal power supply, the distance between the passive RFID tag and the RFID reader is limited, usually within a few meters, and generally requires a higher power RFID reader.