Industrial Communication Systems

Radio Frequency Identication 8-11

years without battery replacement. In other words, no battery replacement is needed before the car is

replaced

by

a

new

one.

Compared

with

the

most

energy-ecient

active

RFID,

it

has

extremely

long

life

expectancy.

8.13 Backscattering

Although semi-active RFID is very versatile and reliable, it nds limited utilizations because its tag is

expensive

in

absolute

and

relative

terms.

Of

course,

the

nite

life

span

and

the

bulkiness

of

its

tag

are

also

fac

tors

of con

cern.

Based

on

the

successful

development

of

the

passive

HF

RFID,

attempts

to

develop

a

long-range

sys-

tem

with

inexpensive,

low

prole,

and

passive