The difference and connection between active and passive RFID

RFID (Radio Frequency Identification), commonly known as "electronic tags", is a non-contact automatic identification technology that automatically identifies target objects and obtains relevant data through radio frequency signals. The identification work does not require manual intervention, and its main function is to write and read data. It consists of tags, interpreters, and data transmission and processing systems. According to whether the electronic tags are equipped with batteries, they are divided into two types: active and passive.

 

At present, passive electronic tags account for 80% of the market, while active electronic tags only account for less than 20%. So what are the differences and connections between active tags and passive tags?

 

1. Definition

Active RFID, also known as active RFID, is powered entirely by internal batteries. At the same time, some of the battery's energy supply is converted into RF energy required for communication between electronic tags and readers, usually supporting remote identification.

Passive tags, also known as passive tags, can convert some microwave energy into direct current for their own operation after receiving the microwave signal announced by the card reader. 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 the data from the RFID chip. With anti-interference ability, users can customize the reading and writing of standard data, making it more efficient and efficient in specialized application systems, with a reading distance of over 10 meters.

 

2. Working principle

Active electronic tags refer to tags that work with energy provided by batteries. The battery, memory, and antenna together form an active electronic tag, which is different from the passive RF activation method and continuously sends information through a set frequency band before battery replacement.

The performance of passive RFID tags is greatly influenced by tag size, modulation form, circuit Q value, device power consumption, and modulation depth. The passive RF tag has a memory capacity of 1024bits and an ultra wide operating frequency band, which meets relevant industry regulations and can be flexibly developed and applied. It can read and write multiple tags at the same time. Passive RF tag design, no battery required, memory can be repeatedly erased more than 100000 times.

 

3.Price and service life

Active RFID: High price and relatively short battery life.

Passive RFID: The price is relatively cheap compared to active RFID, and the battery life is relatively long.

 

4.Advantages and disadvantages

(1)Active RFID tags are powered by built-in batteries, and different tags use different numbers and shapes of batteries.

Advantages: Long operating distance, the distance between the active RFID tag and the RFID reader can reach tens of meters, or even hundreds of meters.

Disadvantages: Large size, high cost, and limited usage time due to battery life.

(2)The passive RFID tag does not contain a battery, and its electrical energy is obtained from the RFID reader. When the passive RFID tag approaches the 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 the data from the RFID chip.

Advantages: Small size, light weight, low cost, long service life, can be made into different shapes such as thin sheets or hooks, and applied in different environments.

Disadvantage: Due to the lack of internal power supply, the distance between passive RFID tags and RFID readers is limited, usually within a few meters. Generally, high-power RFID readers are required.