5

Typical Applications for HSMP-481x Low Inductance Series (continued)

Co-Planar Waveguide

Groundplane

Center Conductor

Groundplane

0.3 pF

0.75 nH

Equivalent Circuit Model

HSMP-381x Chip*

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.

Figure 10. Circuit Layout.

Figure 11. Equivalent Circuit.

0.18 pF*

* Measured at -20 V

2.5

Ω

I = Forward Bias Current in mA

*See AN1124 for package models.

80

I