RFID Tag

1 April 2018 - 0 Comments

RFID Tag

RFID Tag Internal Structure

RFID TAGS are mainly divided in to two types - PASSIVE RFID TAGS and ACTIVE RFID TAGS. PASSIVE RFID TAGS are the TAGS with no internal power source. And ACTIVE RFID TAGS are TAGS with their own power source. We will discuss each of them briefly below.

PASSIVE RFID TAGS

In PASSIVE RFID Tags we have generally two main components. One is ANTENNA COIL and another is MICROCHIP. As you can see in the above image, there is no BATTERY or any other ACTIVE POWER here.

Working:

With no power source the usually TAG stays ideal. The whole process starts with RFID transmitter. The transmitter generates the electromagnetic radiation through its antenna. When tag gets in range of transmitter, the TAG ANTENNA COIL gets energized through ELECTROMAGNETIC INDUCTION. This energy acts as power source for the MICROCHIP in TAG. This MICROCHIP uses this energy to provide a feedback response for the transmitter. The transmitter receives this response which is unique to the tag and provides the corresponding output.

All PASSIVE TAGS works the same way.

Where PASSIVE TAGS Are Used?

There are various reasons to use PASSIVE TAGS; few are as below:

1. When you want cheaper TAGS. PASSIVE TAGS are very cheap to buy and are available massively. So replacing them will be easy.

2. When TAGS need to be slim. PASSIVE TAGS are very slim. There are available as thin as paper and as small as finger nail.

3. When you need high life. PASSIVE tags do not need any power, so once they are installed in a system they can work for a lifetime.

Types of PASSIVE TAGS

PASSIVE tags are further divided based on operating frequency. As it is known the functioning distance depends on operating frequency, with higher frequency the TAG will be recognized from farther distance. Also with higher frequency the system will be influenced less by other systems.

Low frequency: 125 KHz works up to 10cm.Usually used for ID cards.

Medium frequency: 13.5MHz works up to 1meters. Usually used at airport security.

High frequency: 900MHz works up to 30 meters. Usually used for File tracking and package tracking

How to Use PASSIVE RFID TAGS

Using PASSIVE tags is quite easy. All you need to do is bring the tag near the TRANSMITTERS effective range and all the work will be done by MICROCHIPS present in TRANSMITTER and TAG.

Applications of Passive RFID Tags

Security systems
Medical tags
Package Identification
Theft protection systems
Data authorization
Unique Identity
Body implants

ACTIVE RFID TAGS

ACTIVE TAGS are tags with power sources fixed internally. So for them there will be usually three main components. One is ANTENNA COIL, second is MICROCHIP and third is power source. For ACTIVE TAGS power sources are usually non rechargeable batteries. These systems usually last for 2-5 years. Once the battery is dead it needs to be replaced for the tag to work again.

There is no standard model for ACTIVE RFID TAGS, they are normally custom made and are available in different sizes and shapes. Appropriate one is chosen depending on requirement. The active tags with battery source on the body are usually bulky.

Where to use ACTIVE TAGS

1. For higher range - Active tags can respond to distances many times higher than passive tags. So ACTIVE TAGS are used for high distance detection.

2. For accurate position - Active tags provide more accurate position then passive ones. Hence active systems are used when direction of system is important.

Types of ACTIVE RFID TAGS

ACTIVE TAGS are divided in to two types based on their working. They are namely Transponders and Beacons.

Transponders: These Tags acts as passive tags and sit ideal under any instance until they receive a signal from transmitter. Once they receive the signal the Transponders turns active and sends a response to the transmitter. By staying ideal these tags save power and usually last longer. These type of tags are used at tool booths

Beacons: These tags will be ON 24x7 and will be providing specific information for every few seconds. These tags usually have a working range of few hundred meters. These types of tags are used in oil rigs and other industries.

Although they have differences both PASSIVE and ACTIVE TAGS are popular for their own reasons. And both are used extensively.

How to Use ACTIVE RFID TAGS

Using ACTIVE tags is similar to PASSIVE ones. All you need to do is bring the tag near the TRANSMITTER effective range and all the work is will be done by MICROCHIPS present in TRANSMITTER and TAG.