Passive RFID Tags

Understanding Passive RFID Tags

RFID tags are used to store digital information within an object. They are dependent on the RFID reader

RFID tags are used to store digital information within an object. They are dependent on the RFID reader for extracting the information stored within the tags in the form of smart barcodes.

RFID tags are categorized into active tags (i.e ones which operate on battery) and passive tags (which operate without any external source of power).

Passive RFID tags can are completely dependent on the power sources (electromagnetic energy) of RFID reader.

These radio waves charge up the coiled antenna present in the passive tags. After being provided with charge, power source moves from antenna to IC.

Thus powering the chips which then sends back the signal to radio frequency system. This overall process is known as backscatter which is detected by the reader and information is interpreted out of it.

Advantages of Passive RFID Tags

Life Span is Dependent on the Working Environment

Life span of passive tags depends on the environment they are operating in and also on the type of materials that they have been made of. If a tag is being operated in better environment the life span is expected to be up to 20 years or more.

Cost is Quite Moderate

These type of tags are lesser in price than active RFID tags and even the manufacturing cost of these tags is less.

Smaller in size

The design of these tags are very small which justifies its small manufacturing cost.

Generation of less noise

Lesser noise is generated in these tags as the circuit board is inductive as well as printed with radiative coupling.

Disadvantages of Passive RFID Tags

Works for Short Range Only

The absence of antenna in RFID tags makes it impossible to send or receive the signals to long ranges. Thus these tags are only operating within shorter ranges irrespective of low or high frequencies. Thus the maximum communication range can be of 2 feet.

Even if high frequency is used still the best range of these tags for connecting with readers is 20 feet, which is considerably low too.

Inefficient at Storage

Since the battery is absent, they are inefficient at storing too much of information.

Also Read: RFID Security & Privacy Issues You Need to be Aware Of

Dependency on External Power Source

RFID tags on their own are of no use unless a RFID reader is brought into its contact to extract the digital information stored within these tags.

Absence of Sensors

To store the information, most of the sensors are dependent on constant power for everyday operations. Since no sensors are used in Passive tags, thus making it non compatible for sensing applications.

What are Battery Assisted Passive RFID Tags?

Battery assisted passive RFID tags are also known as semi-passive or semi-active tags. They are called so because of the presence of the internal battery.

These tags are also dependent on RFID readers but their mechanism of responding differs them from that of passive tags.

In battery assisted passive RFID tags, the internal battery while receiving the radio frequency signal from RFID reader powers the integrated circuits. Thereafter, the signals are returned by such tags to RFID readers.

Price Range for Different Types of RFID Tags

For taking the complete benefits of RFID tags a lot of things need to be considered. These include the labor cost and real –time data needs.

If real time data is not important to you and labor costs are low then the passive RFID tags would be your best option.

Whereas if labor costs are high and real time data is important then the active RFID tags make for a better solution. Below mentioned is the breakdown of the costs of different types of tags:

Basic Passive RFID tags

Such tags are priced anywhere around $0.10 USD each and are mostly utilized on paper, non-metal and liquid materials.

Metal Passive RFID tags

Larger in size than passive tags and mostly used for metal assets, these tags are valued around $ 1 USD.

Active RFID tags

Completely automated, these tags are a bit expensive ranging from $15 to $20 a piece.

Difference Between Active RFID Tags and Passive RFID Tags

Difference between Active RFID Tags and Passive RFID Tags

Also Read: 5G Network Architecture Explained With Diagram


Jason Hoffman

I am the Director of Sales and Marketing at Wisdomplexus, capturing market share with E-mail marketing, Blogs and Social media promotion. I spend major part of my day geeking out on all the latest technology trends like artificial intelligence, machine learning, deep learning, cloud computing, 5G and many more. You can read my opinion in regards to these technologies via blogs on our website.