Circular And Linear Versions - KVH Industries TracVision M5 User Manual

Circular and Linear Versions

Your TracVision system is configured to receive either circularly
polarized satellite signals (e.g., North America) or linearly polarized
satellite signals (e.g., Europe or Latin America). Figure 1-3 illustrates
the difference between these two polarizations.
Figure 1-3 Polarizations of Satellite Signals
Circular
Signals transmitted in two
"corkscrew" patterns, one
running clockwise and one
running counter-clockwise
LNB Skew Angle
Since linear satellite signals are oriented in a precise cross pattern, the
TracVision antenna's receiving element, called an LNB (low-noise
block), must be oriented in the same way to optimize reception. This
orientation adjustment is referred to as the LNB's "skew angle."
Figure 1-4 illustrates how skew determines the amount of a linear
signal that the LNB collects. The more signal, the better the reception.
Figure 1-4 How Skew Works
Bad Skew Good Skew
= Satellite Signal
TracVision M5/M7 User's Guide
Chapter 1 - Introduction
Linear
Signals transmitted in vertical
and horizontal "waves" offset
exactly 90º from each other
Ideal Skew
= LNB "Signal Collector"
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