Dielectric Communications says its HD Radio Series Interleaved Antenna System has been installed at Cumulus-owned WNNK(FM) in Harrisburg, Pa. to allow simultaneous transmission of analog and digital signals from the same antenna aperture.
The mountainous terrain surrounding the transmission site provided station
engineering staff with a good environment to test digital and analog
signals in multipath areas, according to Dielectric and digital signal reception was strong and clear in those multipath areas.
Chief Engineer Dave Supplee said, “Our spectrum analyzer showed that where multipath conditions reduced the analog signal level substantially, the digital signal level was affected minimally. In many instances, the low-power digital displayed actual signal strength comparable to that of the high-power analog signal without any sign of interference.”
The Dielectric HDR Series Interleaved Antenna System, one of the company’s high-efficiency, low-level IBOC combiner solutions, is comprised of two complete circularly polarized antenna arrays that are interleaved at half-wave intervals on a supporting structure. A reverse polarization technique maximizes the isolation between the analog and digital signals, and at WNNK this separation is enhanced further with a low-power isolator. Because the tower geometry is identical for both arrays, this new antenna system ensures the same azimuthal coverage area for both analog and digital arrays, said the company.
Dielectric says interleaving can be applied to any of its side-mounted circularly polarized antenna elements, giving broadcast operations flexibility to implement and support an integrated HD radio system. Antenna systems already deployed in the field can be retrofitted with this new system to provide full IBOC integration without the need for a high-level, high-loss combiner method.
WNNK Uses Dielectric For HD Radio Antenna
WNNK Uses Dielectric For HD Radio Antenna