Page 364 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim

344 IDT MICROSENSOR PARAMETER MEASUREMENT

Synthesized sweeper Power Macintosh
0.01–40 GHz 6100/66

HP 8510B
Network analyzer HP plotter

Test set Apple
0.045-40 GHz
laser printer
Port l Port 2

Coaxial Sample holder with Coaxial
cable SAW device cable
T101 T101

1 1

Figure 11.6 Schematic of measurement setup

H
S 21
i
s 11 S 22

1

S 12

Figure 11.7 Signal flow of a two-port network

11.9 CALIBRATION

Calibration of any measurement is essential in order to ensure the accuracy of the system.
The errors that exist in systems may be random or systematic. Systemic errors are the
most significant source of measurement uncertainty. These errors are repeatable and can
be measured by the network analyser. Correction terms can then be computed from these
measurements. This process is known as calibration. Random errors are not repeatable
and are caused by variations due to noise, temperature, and other environmental factors
that surround the measurement system.