SFNStar™ Low Downward Radiation UHF Slot Antenna

A new patented slot antenna technology for DTV, SFNs, 700 MHz Mobile
TV networks and critical high RFR sites

The SFNstar™ series of antennas are low RFR slot antennas that have up to 30 dB less RFR at high
depression angles as compared to standard slot antennas. The SFNstar™ antennas are great for DTV,
700 MHz Mobile TV and SFN networks that use short towers or building rooftops. The SFNstar™ antennas
are the same physical size as standard slot antenna and are available in a wide range of azimuth patterns,
plus horizontal or circular polarization. The SFNstar™ antenna technology produces a very low group
delay and V.S.W.R profile across a 6 or 8 MHz wide channel. The antennas are available in a frequency
range of 400 to 1700 MHz, with input powers up to 50 kW at 700 MHz

The SFNstar™ technology is a combination of current UHF slot antenna
design principals plus some new innovative ideas from RFT
The antenna is designed much the same way as a conventional slot antenna. To lower the high angle
axial radiation, the effective spacing of the bay to bay slots is decreased using patent pending TEM mode
networks, and coupling structures. This reduces the high angle radiation lobes, and also reduces coupled
RF currents to the tower along the axis of the antenna. It also reduces signal reflections off of nearby
towers and structures. The physical footprint of the antenna is similar to current slot antennas on the market.

SFNstar™ technology antennas feature higher unit elevation gains
Since the antenna has much less radiation at high depression angles, the antenna exhibits between 10 to 15% more elevation gain
than a similar sized standard slot antenna. In some cases this will allow the use of a bay or two smaller antenna to get the same gain
as compared to a standard slot antenna design.

SFNstar™ low RFR pylon antennas come with a lot of options
The SFNStar™ antennas are available in a wide variety of standard and custom azimuth patterns. Power input levels range from
4 kW to 50 kW, with center and end fed versions. Horizontal and Circular polarized models are available. Sectionalized models are
available for easy rooftop installation and elevator transport.

Elevation Plot of a standard 8 bay slot antenna versus a SFNstar™ antenna