Programming instructions

RF Components
Multisim Component Reference Guide 14-4 ni.com
14.6 Strip Line
Stripline is one of the most commonly used transmission lines at microwave frequencies.
Stripline is coined for ground-conductor-ground transmission line with a dielectric (normally
air) in between. Due to the multiplicity of the circuit functions, substrate, technologies, and
frequency bands, there is a wide range of stripline conductors. For example, microstrip lines
are a special type of stripline where the upper ground is placed at infinity. Depending on the
position of the stripline conductors, the shape of the conductor, and the thickness of the
conductor, the equations governing the behavior of one stripline to another differ. For
example, the centered stripline (often called Tri-Plate line), is a stripline where the
conductance is placed symmetrically in each position (from top, bottom, left, and right).
Another example is the Zero-Thickness stripline which is a very good approximation for
striplines in which the thickness of the conductor is negligible compared to the distance it has
from the ground planes.
14.7 Ferrite Beads
Ferrite beads are used for decoupling (blocking unwanted signals) on DC supply and some
signal lines. They also provide attenuation of selected frequency bands.
The physical shape of a bead is similar to a toroid, but the bead has greater length to diameter
ratio and usually a greater outside to inside diameter ratio than most toroid cores. Where the
length to diameter ratio is even greater, the bead is often referred to as a sleeve. Different size/
shape beads of the same material have different degrees of suppression. When used in
conjunction with a bypass capacitor, a ferrite bead can provide extremely good decoupling.
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