Dielectric announced this week a new switchback mask filter that's specifically optimized for the 700 MHz broadcasting spectrum. The filter can handle up to 1.8 kW, but is small enough to fit in a standard 19-inch rack.
It meets the FCC stringent mask filter requirements and insertion loss is less than 1.1 dB. Temperature compensation maintains response within +/- 10 kHz over a range of 0 to 45 degrees C. And the filter's VSWR is less than 1.25:1. While the filter's insertion loss and VSWR performance doesn't match that of high power filter mask filters most broadcasters are familiar with, it could be a reasonable trade-off, given the small space requirements and the useful power level.
"By designing our new 1.8 kW filter with a distinctive mechanical folding structure, we've ensured that it can be implemented easily into a wide range of transmission stations, large and small," said Dielectric president, Garrett VanAtta. "Broadcasters, regardless of the antenna type they are utilizing, will find it to be a simple, plug-and-play integration into their existing set-up. The 700 MHz market has very stringent requirements that broadcasters must meet, and our new filter is engineered to make it easier than ever for our customers to fit into this spectrum and still expect superior quality in their transmissions."
While it may take a bit more space, a version of this filter that works in the broadcast TV band below 700 MHz should also be of interest to broadcasters who are installing boosters and distributed transmission systems.
