Skip navigation

An interesting look into the history of RF and its origins

By:
Posted: 25th July 2013
Category: General Blog Posts

After moving from the industrial fasteners and fixings market into electronic components distribution predominately focussing on RF products, I was interested to look into the history of RF and its origins to better understand the products and their uses in today's modern technology.

The history of radio frequency identification technology is generally believed to have evolved from World War II. After the discovery of radar in 1935 by Scottish physicist Sir Robert Alexander Watson-Watt, the British, Germans, Japanese and Americans were all using radar to warn of approaching planes, the issue being there was no way to identify between which planes belonged to the enemy and a country's own returning from a mission.

The Germans discovered that if pilots on return to base rolled their planes it changed the radio signal that was reflected back, this essentially alerted the radar crew on the ground that these were German and not allied aircraft, this crude method was in effect the first passive RFID system.

In a secret project headed up by Watson-Watt, the British developed the first active identify friend or foe (IFF) system. By placing a transmitter on each plane, which broadcast a signal back when it received signals from radar stations on the ground that identified the aircraft as friendly.

This is the basic concept on which RFID works. A signal is sent to a transponder, which responds and either reflects back a signal (passive system) or broadcasts a signal (active system).

With advances in radar and RF communications continuing through the 1950s and 60s, into how RF energy can be used to identify objects remotely; the technology has been developed commercially for anti-theft systems using radio waves to determine whether goods had been paid for or not.

These electronic article surveillance tags, which are still used today in packaging, have a 1-bit tag. The bit is either on or off, when the item is paid for the bit is turned off and the goods can leave the store, if the goods are not paid for and try to be taken out the store readers at the door detect the tag and sound an alarm.

The first RFID patents were submitted in the early 70's in the US, including Mario Cardullo's device, the first true ancestor of modern RFID, a passive radio transponder with memory.

RFID tags are used in many industries. The numerous uses for this technology include among other things controlled access keyless locks – a card with an embedded transponder communicates a signal to a reader near the door, the reader unlocks the door when a valid identity number stored within the RFID tag is detected. Also used as an anti-theft device in cars, with a reader in the steering column reading the passive RFID tag in the plastic housing around the key. If it doesn't get the ID number it is programmed to look for, the car won't start. These tags have also been developed for automated toll payment systems, tracking cars, people, animals, equipment, and more recently contactless payment via mobile phone.

RFID offers numerous advantages over manual systems or the use of bar codes. The tag itself can be read if passed near a reader, even while covered or not visible, such as embedded in the object or inside a case, carton box etc, and crucially unlike barcodes, RFID tags can be read hundreds at a time. Bar codes can only be read one at a time using current devices.

The value of the RFID market in 2012 was estimated at $7.46 (USD) billion and with the RFID world market estimated to surpass $20 billion (USD) by 2014, the three key factors driving the significant increase in RFID usage are decreasing cost of equipment and tags, increased performance to a reliability of 99.9%; and an international standard around UHF passive RFID. With RFIDs becoming increasingly smaller, researchers at Bristol University successfully glued RFID micro-transponders to live ants in order to study their behavior. This trend towards increasingly miniaturized RFIDs is likely to continue as technology advances.

Julie Caulkett, 17th July 2013