Belden: leadership in HD technology
Date: Fri, 09/09/2011 - 15:44
Hundreds of millions of viewers around the world depend on Belden for reliability and quality when they are watching live coverage of the world’s largest sports events. Designed for the perfect capturing, live or post production processing, routing and delivery of content, Belden cables are the first choice for TV/ Radio stations, film and recording studios, performance and sports venues. They are used extensively in audio, video, lighting and camera applications. Providing top performance and high reliability, Belden cables meet the specific requirements of even the most demanding technological constraints of time and mission critical applications such as news or sports broadcasting in high definition (HD) video.
In radio, TV or post-production applications, the key advantages include improved picture and sound quality as well as interactivity. Werner Eich, Vertical Market Manager VSS for Belden, says: “Radio and Television broadcasters are going all-digital. Now the digital formats are being adopted by recording studios, video post-production and film production facilities, and many associated applications. The reason is clear – the digital format provides superior A/V performance. This digital transition is leading to a similar revolution in High Definition TV (HDTV).”
Although the digital format promises to revolutionize the broadcast industry, it also poses a challenge when it comes to designing, choosing, and installing a new system. Werner Eich said: “Broadcasters, television production studios and post-production enterprises are adopting high definition, serial digital imaging (HD/SDI) as their format of choice because of its superior performance and other advantages.”
Precision digital video is processed in real time and is extremely stable, which reduces equipment adjustments and allows copies or reproductions to retain the same quality as the original. Moreover, signal degradation is virtually eliminated and noise immunity is greatly improved. Digital technology not only promises to improve picture and sound quality, but also paves the way for interactive on-demand TV and other digital services.
Cable manufacturing consistency and quality are both key to achieve minimal return loss. Good practice requires testing to the third harmonic of the operating frequency. For HD, single cable should be able to deliver 1080p, that means testing to a frequency of 4.5 GHz. This 1080p format is expected to transmit HD video signals at 3 Gb/s, requiring an operating frequency of 1.5 GHz. This translates to a shorter wavelength and a greater chance that inconsistently manufactured cables will choke off the signal with a high level of return loss. This may be caused by even the slightest irregularity in the cable manufacturing process. A slightly bent shaft, bad bearing or uneven cable tension, for example, can cause reflection and affect the signal wavelength. Therefore, utmost consistency and control in the manufacturing process is essential to the reliability of the cable’s signal transmission at high frequencies and to minimize return loss.
Increased sweep testing
Therefore, broadcast camera and video cables need to deliver top performance, whilst at the same time meeting extended international and European standards.
It is for this reason that Belden became the first cable manufacturer to increase its sweep testing from 3 GHz to 4.5 GHz for all coaxes designed for maximum bandwidth, minimum return loss and minimum attenuation loss. These cables already meet the very tight specifications for electrical properties and are ideally suited for both analog and digital video in broadcast, post-production and other critical video applications. In addition, Belden performs 100% sweep testing to 4.5 GHz on every reel of HD cable and provides certification to assure unequalled levels of cable signal integrity and reliability, with lower return loss (RL) at higher frequencies.
Werner Eich: “We are prepared for the future. As a pioneer and leader in cable technology, Belden has always taken a stringent approach to cable quality assurance. Rather than simply inspect and test random batches of cables after manufacturing, Belden begins its quality process in the product development and manufacturing stages.”
When an independent test laboratory took an in-depth look at the HD performance of the video coaxes used in TV studios, cables were tested for return loss, attenuation and maximum cable run on HD (1080i and 720p). In the end results all Belden products delivered performance values that exceeded the industry standards.
Belden continually introduces new developments and products for a range of different applications for the creation, production and delivery of entertainment content, including Mobile TV, IPTV and D-Cinema.