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11.5 Conclusions...................................................................................................................... 227
References................................................................................................................................... 228
199
11.1 Introduction
Typically, the biggest metric of concern for RFID tags and, in particular, the silicon controller
devices for the tags has been production cost. In chip fabrication terms, the cost of the
device directly relates to the CMOS process chosen for implementation and the area of
the device produced. Older CMOS processes such as 0.18??“0.35 mm are targeted for RFID as
they are relatively cheap to produce than the newer 65??“90 nm processes. The design goal is
to create a device with the smallest area using one of these older processes. However, one
metric that has been held secondary is the power consumption of these devices.
RFID tags generally come in two types, passive and active. Active tags include an
internal power source (usually a battery) to power the transceiver used for receiving
queries and transmitting responses and the controller that computes the tag??™s responses
to transactions. The controller is typically either an ASIC or a low-power embedded
microprocessor. Passive tags do not contain an internal power source.
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