RFID: Old Tech with a Twist


How does RFID work? Where does it come from? How do we use it today?

RFID, or radio frequency identification, is a newer take on an old technology. With its roots in World War II espionage, this tech has been around for quite a while.

Not until relatively recently has this form of wireless communication become inexpensive and accurate enough to be commercially viable for a variety of applications.

How Does RFID Work?

RFID is a system with two parts: a tag and a reader. The tag consists of a microchip and antenna. The reader contains a scanning antenna and transceiver.

The reader uses radio waves to activate the tag. The tag then responds with its own radio wave, which the reader translates into data.

A notable predecessor to RFID is the covert listening device nicknamed “The Thing” created by Russian scientist Léon Theremin (yes, that Theremin) for the USSR to spy on the USA during World War II. This device contained no internal power source, so it had to be activated by external radio waves.

This clever use of a passive, radio-activated “tag” allowed the USSR to listen in on important meetings in the US ambassador’s office for 7 years!

Passive vs Active

The two main types of tags are passive and active.

A passive tag does not have its own power source; it draws energy from the reader, just like “The Thing”.

An active tag operates with its own battery power. This independently powered tag allows for a boosted communication range.


RFID systems operate using 3 main frequency types: low, high, and ultra-high. Different frequencies are used for different applications, depending on the transmission range needed. Generally speaking, the higher the frequency is, the longer the range.

Modern Usage

You’re most likely to encounter contemporary RFID in the form of toll tags, access badges, and hotel room key cards. RFID is also used to microchip livestock and pets. The retail and transportation industries use this technology to track and manage assets and inventory.

As this technology becomes less expensive and more accurate, we can expect to see it pop up in advertising, sports, education, and healthcare.

Valerian Technologies prints on RFID stock! Order your access badges or hotel key cards today!


References: RFID JournalInternet of Things AgendaWikipediaCrypto Museum