Section 11.3 describes a power macromodeling technique that
works in concert with the RFID design automation ?¬‚ow described in Chapter 13 and allows
the effective evaluation of alternate protocol designs. Section 11.4 presents the design and
evaluation of a passive active RFID tag that has many of the bene?¬?ts of an active tag that uses
considerably less energy. In particular, we describe a passive switch for an active transceiver
called the burst switch and a power-aware packet storage and ?¬?ltering technique called the
smart buffer. Each of these techniques allows us to save power by allowing high energy
consumption components of the tag to be powered down.
11.2 Increasing Memory Capacity
Conventional writable memories require some static power to retain their stored values.
However, passively powered devices require nonvolatilememories that retain the values stored
even when the device is not powered. Nonvolatile memories currently employed on passive
tags are typically very small (e.g., <200 byte) due to small power budgets of passive tags.
In this section, a memory architecture is presented that can be employed to expand the
memory capacity of fully passive tags and can be employed to lower energy consumption
200 RFID Handbook: Applications, Technology, Security, and Privacy
in active tags or hybrid passive and active tags.
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