10
1.5 nH
1.5 nH
50 OHM MICROSTRIP LINES
0.3 pF*
0.3 nH
0.3 nH
PAD CONNECTED TO
GROUND BY TWO
VIA HOLES
*0.8 pF TYPICAL FOR HSMP-4820
Figure 33. Circuit Layout.
Figure 34. Equivalent Circuit.
Microstrip Shunt
Connections for
HSMP-48XX Series
In the diagram above, the
center conductor of the
microstrip line is interrupted
and leads 1 and 2 of the
HSMP-38XX series diode are
placed across the resulting gap.
This forces the 0.5 nH lead
inductance of leads 1 and 2 to
appear as part of a low pass
filter, reducing the shunt
parasitic inductance and
increasing the maximum
available attenuation. The 0.3 nH
of shunt inductance external
to the diode is created by the via
holes, and is a good estimate for
0.032" thick material.
Co-Planar Waveguide
Groundplane
Center Conductor
Groundplane
0.75 nH
0.3 pF*
*0.8 pF TYPICAL FOR HSMP-4820
Figure 35. Circuit Layout.
Figure 36. Equivalent Circuit.
Co-Planar Waveguide
Shunt Connection for
HSMP-48XX Series
Co-Planar waveguide, with
ground on the top side of the
printed circuit board, is shown
in the diagram above. Since it
eliminates the need for via holes
to ground, it offers lower shunt
parasitic inductance and higher
maximum attenuation when
compared to a microstrip circuit.
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
