1WTCHigh atop One World Trade Center in Lower Manhattan, workers with wireless and broadcast infrastructure specialist Radio Frequency Systems (RFS), are installing a pair of trial antennas for television broadcasts.

Topping out at 1,776 feet, the antenna support makes One World Trade the tallest building in the Western Hemisphere, making it an ideal platform to deliver terrestrial television services to the entire New York City coverage area. Working closely with the Metropolitan Television Alliance (MTVA), The Durst Organization and individual broadcasters, RFS is collecting data from both its UHF and VHF trial arrays to demonstrate how the system and venue will perform.

“Following 9/11 and decimation of broadcast infrastructure in the ruin of the Twin Towers, RFS supplied a standby antenna to help get Lower Manhattan television broadcasts back on air. We recognized the tremendous importance of this project at the time and, with One World Trade now rising as the new icon of New York City’s cityscape, we are proud to once again be involved,” said Jay Martin, vice president of global broadcast sales, RFS.

RFS has done a number of high profile tall building applications globally including the Pearl Tower in Shanghai, Sears Tower (Willis Tower) and John Hancock in Chicago, Skytower in Auckland, New Zealand, Sichuan Tower in China, Baiyoke Tower in Bangkok, Thailand and others.

RFS had previously provided passive digital antenna system (DAS) equipment for One World Trade’s main building through a system integrator. With some systems, the polarization ratio is fixed and must be agreed upon by all broadcasters using a common antenna. The Durst Organization was looking for a future-proof solution that would offer maximum flexibility to all broadcasters. With the new arrays, broadcasters will be able to set their own polarization ratios, independent of other broadcasters.

Polarization is a property of waves that can oscillate with more than one direction or orientation in reference to the earth. An antenna is vertically polarized (linear) when its electric field is perpendicular to the Earth’s surface. An example of a vertical antenna is the broadcast tower for AM radio. Horizontally polarized (linear) antennas have their electric field parallel to the Earth’s surface. Horizontal polarized antennas are commonly used for television transmission.

Installed at the top is a UHF array of eight levels on a single face, the PEP8A, and below it is the VHF 662-4A antenna. The test antennas are required to prove the vertical radiation patterns and system performance from the One World Trade Center site as the first step in getting to a final configuration.

“These tests will demonstrate the advantages of broadcasting from this state-of-the-art site, and we’re very happy that RFS is supporting our efforts with their antenna systems,” said John Lyons, assistant vice president and director of broadcast communications at The Durst Organization. “We believe that One World Trade Center will become the premier transmission site for over-the-air TV and FM radio broadcasting.”