Radio Frequency Systems (RFS) will exhibit elements of its end-to-end mobile TV RF solution-set at the Mobile World Congress in Barcelona. The suite features a series of lightweight and low-profile UHF monopole antennas that are ideal for overlaying at cellular base stations, plus advanced filtering solutions and the company's CELLFLEX foam-dielectric transmission line.
According to Mick Bennett, RFS Global Product Manager for Broadcast and Defence Systems, deploying broadcast mobile TV services–such as digital video broadcast to handhelds (DVB-H)–at existing cellular base stations presents a new set of overlay challenges. "Mobile TV overlays make great use of existing site infrastructure, but they also introduce new antennas that may impact leasing agreements," he said. "It is therefore essential for antennas to be lightweight and visually unobtrusive. In addition, mobile TV services can interfere with existing cellular services; for this reason, UHF frequencies less than 700MHz are being preferred, plus new filtering solutions are being developed to prevent co-location interference in the cellular receivers."
Bennett explained that a two-stage RF filtering process will be required for mobile TV overlays: critical DTV transmission mask filtering and low-pass filtering to prevent the higher-power mobile TV signal from blocking cellular receivers. At Mobile World Congress, RFS will exhibit the first of its new low-pass RF filters. which attenuates all frequencies, including harmonics, above a nominated UHF broadcast frequency. This complements RFS's full range of six- and eight-pole cross-coupled coaxial bandpass filters that provide mask filtering.
Also on display will be several lightweight and low-profile mobile TV antennas–such as the broadband vertically polarised omnidirectional SDV4 antenna, which delivers top-class performance for its slight size (2.25m tall and 320mm diameter). Even more slimline is the ultra-lightweight HU6 series omni antennas, which weigh just 3.5kg. RFS's comprehensive portfolio also includes horizontally polarised options, including the popular superturnstile omni antenna.
"RFS is a specialist in all aspects of RF technology–from sophisticated filtering solutions, through to a wide range of antennas and transmission line," Bennett said. "This extends to high-power broadband systems, which are also being considered for mobile TV, plus wireless indoor solutions. It's widely recognised that indoor mobile TV coverage in locations such as airports, shopping malls and metro tunnels is going to be essential. RFS is currently developing a whole new range of passive and active RF technologies for such mobile TV applications as an extension of its ClearFill range."
RFS will be at Mobile World Congress 2007: Hall 2, Stand C53, Venue Fira de Barcelona, Montjuic, Barcelona, Spain, 11 to 14 February 2008.