Typical Applications for HSMP-481x Low Inductance Series (continued)
Co-Planar Waveguide Shunt Connection for HSMP-481x
Series
Co-Planar waveguide, with ground on the top side of the
printed circuit board, is shown in Figure 10. Since it elimi-
nates the need for via holes to ground, it offers lower shunt
parasitic inductance and higher maximum attenuation
when compared to microstrip circuit.
Co-Planar Waveguide
Groundplane
Center Conductor
Groundplane
Equivalent Circuit Model
HSMP-381x Chip*
R
s
R
j
2.5
Ω
C
j
R
T
= 2.5 + R
j
C
T
= C
P
+ C
j
R
j
=
80
Ω
I
0.9
I = Forward Bias Current in mA
0.18 pF*
* Measured at -20 V
*See AN1124 for package models.
Figure 10. Circuit Layout.
R
j
0.3 pF
0.75 nH
Figure 11. Equivalent Circuit.
5
AVAGO [ AVAGO TECHNOLOGIES LIMITED ]
