Page 316 - System on Package_ Miniaturization of the Entire System

290 Cha pte r F i v e

20
Simulated
Measured
18
Resistance (Ω) 16

14

12

10
5 10 15 20 25 30 35 40
Frequency (GHz)
FIGURE 5.26 Designed, simulated, and measured resistance up to 40 GHz. [60]

frequencies. Since the CPW topology is determined to provide the best response, the
termination structures are typically fabricated as shown in Figure 5.27 and measured
using through, reflect, line (TRL) calibration [60].

Attenuator Attenuators are typically designed and fabricated using the resistor foils.
The circuits can be created in two ways, using either a T-network or a p-network.
Attenuation is expressed in decibels like most other RF system components. To calculate
the resistance values needed, the attenuation value should be converted from decibels
to magnitude units, and the resulting system of equations should be solved. For a
T-network, the system of equations is
a = 50R (R + R ) (R + 50)
p
s
p
s
and
50 = [(50 + R ) || R ] + R s
s
p