The form factor is
|“||[t]he physical characteristics of a device or object including its size, shape, packaging, handling, and weight.||”|
The form factor of an RFID tag refers to its shape, size, packaging, and handling features. To a large extent, an RFID tag's form factor is determined by the characteristics such as power source and functionality. Some important aspects regarding an RFID tag's form factor include the size of the RFID tag, the weight of the RFID tag, and the method by which the RFID tag is affixed to and removed from its associated object.
RFID tags typically vary in size from smaller than a postage stamp to about the size of a common document stapler. Active tags typically are significantly larger and heavier than passive tags because they have an onboard power supply. RFID tags that integrate environmental sensors are also larger and heavier than those without this functionality. While increasing the computing functionality of an RFID tag increases its cost and power requirements, it may not have an impact on its form factor because the microchip on a passive tag is one of the RFID tag's smallest components. On most passive tags, the largest component on the RFID tag is its antenna.
- Guidelines for Securing Radio Frequency Identification (RFID) Systems, Glossary, at B-1.