South Africans invent the first new TV antenna in decades and usher in a new era of digital reception.
HIDETSUGU YAGI’S ENDURING ANTENNA DESIGN has lasted more than nine decades on rooftops from Sandton to Chicago. Yet it might not make its 100th birthday, thanks to three South African inventors.
Designed to help South Africans – particularly low-income households – make the transition from analogue to digital TV broadcasts, the radically new foldable antenna is called Digiant. Its name reflects both its purpose (“digital antenna”) and its insect-like structure.
Co-inventors Dr André Fourie (executive chairman and founder of Poynting Antennas), Dr Derek Nitch (Poynting's chief technical officer) and Eduard Walker, CEO of antenna-manufacturer TEMIC, spent the better part of a year dissecting, extruding, designing, cutting and testing designs to create a robust and affordable design. But in the age of satellite dishes, why do we even need a new antenna design?
Because, despite the growth of satellite TV broadcasts, digital terrestrial TV remains the most used way of broadcasting TV, especially free-to-air and public broadcasting TV. In South Africa, the need for an affordable digital TV antenna is even more pronounced. We're late to digital migration – and meanwhile, the International Telecom Union (ITU) has already set aside the traditional analogue broadcasting range for the expansion of other communication services. Those services include advanced mobile and commercial wireless broadband.
Digital migration, besides bringing high-def TV to all South Africans, will also free up some TV frequencies (the digital dividend) for 4G/LTE high-speed Internet. Expect dramatically faster cellular Internet speeds.
The Digiant works in a 470 – 862 MHZ frequency band. It connects to a set-top box that decodes the signal for use by any television. In the process, it frees up the tradi- tional TV broadcast spectrum, while allowing more TV channels on the new, narrower, digital TV frequency.
The Digiant's design is a radical evolution from a Vivaldi horn-type antenna. The inventors simplified this to the six-legged “skeletal” structure so that it traces only the minimal outline of the much more solid plate structure of the Vivaldi. This vastly simplified structure was designed to be mass-produced using advanced aluminium die casting. Each leg is hinged in the middle, allowing the antenna to be folded umbrella-style and shipped in a box ten times smaller than usual.
But being small and foldable certainly doesn't decrease performance. Apart from its strong reception capability, the Digiant has been tested to withstand winds of up to 160 km/h and temperatures ranging from -20 to +70°.
The first of 500 000 units ordered by the government were shipped to border towns in the Northern Cape, allowing analogue broadcasts to be switched off there first and preventing the analogue TV signals from bleeding across the border and interfering with our neighbours' broadcast spectrum.
With the first shipments under way, production is being ramped up to meet the target of 5 million low-income households across South Africa, a target set by the government. But the manufacturers are thinking bigger. “The Digiant has been awarded patent rights in over 30 countries,” says Fourie. “We are investigating licensed manufacturing in several countries that require a low-cost, high-performance digital TV antenna.” PM