In the 1930s, both the Army and the Navy were faced with the challenge of adequately identifying targets on the ground, at sea and in the air. In 1937, the U.S. Naval Research Laboratory (NRL) developed the Identification Friend-or-Foe (IFF) system that allowed friendly units such as Allied aircraft to be distinguished from enemy aircraft. This technology became the basis for the world's air traffic control systems beginning in the late 1950s. Early uses of radio identification through the 1950s were generally limited to the military, research labs, and large commercial enterprises because of the high cost and large size of components. Even so, these expensive and bulky equipment racks were the early forerunners of what is now called RFID. Figure 2.1 shows photos of IFF components next to typical modern day RFID components.
Figure 2.1. IFF Components (left), Modern Day (Active) RFID Components (right)
It was not until the emergence of more compact and cost-effective technologies such as the integrated circuit (IC), programmable memory chips, the microprocessor, and modern day software applications and programming languages that RFID as we know it today was born and moved into the mainstream of broad commercial deployment.
During the late 1960s and early 1970s, companies such as Sensormatic and Checkpoint Systems introduced new uses of RFID for less complex and more widely used applications. These companies began developing electronic article surveillance (EAS) equipment to protect inventory items such as clothing in department stores and books in libraries. Early commercial RFID systems, also known as 1-bit tag systems, were inexpensive to build, deploy, and maintain. Tags required no battery power (passive) and were simply affixed to articles that were designed to trigger an alarm when they came near a reader, usually at an exit door, which would detect the presence of a tag.
Figure 2.2. Milestones During the Early Days of RFID