Multi-Polarized Antennas for Port Communications


Whether it’s from waves or propulsion, ships are moving targets rather than fixed points in space. Obstructions such as shipping containers and cranes also create non-line-of-sight (NLOS) conditions that affect the transmission or receipt of signals. Omnidirectional antennas that radiate and receive wireless signals in all directions can help, but not all omnidirectional antennas have the optimum polarization to meet port communications challenges.

The Importance of Polarization

Polarization describes the shape of an electromagnetic wave as it travels from a sending antenna to a receiving antenna. It’s different than antenna patterning, which is more about the direction in which waves travel. Antennas with linear polarization radiate energy on a single plane, either horizontal or vertical to the Earth’s surface. With dual polarization, antennas can receive and transmit on both the horizontal and vertical planes instead.

Although some omnidirectional antennas are dual polarized, most have a circulation polarization so that radio waves rotate as the signal propagates. This helps to mitigate the reflections that are common when signals travel in all directions and, naturally, encounter obstacles. With port communications, however, the reflections are significant because shipping containers, cranes, and even the ships themselves absorb signals or cause them to bounce-off.

When an antenna receives a signal from multiple angles, multiple times, there can be significant variations in the received signal. Multi-path, fluctuations in signal strength formed by an incoherent combination of signals coming from different directions, can result in fade-outs or drop-outs. That’s a problem for ships that need to communicate their operational status or arrival times, or shipping terminals that need to manage traffic, assign births, and allocate equipment.      

Multi-Polarized Antennas for Port Communications

Multi-polarized antennas have the optimum polarization for port communications because they propagate signals with considerably less loss than other types of antennas and have built-in spatial diversity on every feed. With their three-dimensional geometry, multi-polarized antennas reduce multi-path phase cancellation and have the broad signal patterning that’s needed to capture reflected signals caused by shipping containers, cranes, and other obstructions.

MP Antenna of Elyria, Ohio designs and manufactures multi-polarized antennas for port communications. Products included PortWave omnidirectional antennas with impact-resistant radomes that can also withstand sea water and fresh water. Unlike some other antenna manufacturers, MP also tests its antennas under real-world conditions. Plus, all of MP’s products are Made in the USA.

To learn more MP Antenna’s solutions for port communications, contact us.