US chip radio designer MaxLinear has launched a new diversity chip for ISDB-T handsets in the Japanese market, a move which promises to cut around $2 from the Bill of Materials for providing mobile TV in a handset, and also eliminate external antennas.
Max Linear filed an S1 registration document with the SEC at the beginning of November and is expected to go public shortly in the US, raising something close to $100 million. Prior to this it has raised some $35 million in VC funding bit is already profitable. However it needs the money to branch out into new markets.
While the company is clear that the diversity system it has launched is currently targeted at Japan, where it holds around 70% of the tuner market for ISDB-T 1 seg chips for phones, it characterizes this as a breakthrough technology that can be applied in other mobile TV and broadcast markets around the world.
We have heard of other ‘system on a chip’ diversity chips, but not many and Jim Koutras, Product line manager mobile at Maxlinear, told us, ‘Diversity can be achieved on the antennas by simply switching to the best signal at any point in time, but we have carried it out on chip.
‘There are two antenna signals so the chip picks the best of them and then fills in any gaps with components from the other signal. We’re not putting 2 entire tuners into place here, that would take too much silicon, what we’re doing is more like 1.1 to 1.2 times the silicon effort of a single tuner.
‘Diversity is something that has been understood for about 60 years, but doing it efficiently on a single chip, in CMOS, without doubling the silicon, still takes considerable proprietary design,’ said Koutras.
MaxLinear is clear that this is a first for the Japanese market and that the device will be more profitable for it than its existing devices. It claims to have achieved the diversity in a 3.5 mm square chip, using varying power requirements, which go down as low as 50 mW.
Most mobile TV systems are burst in nature (timesliced) so they have content delivered faster than real time, with the radio on for a moment and then play out what has been received subsequently. But ISDB-T one seg does not work like this. While DVB-H for instance will use 165 mW at peak and 25 mW at its lowest power, it will average something like 45 mW or less, in modern chip designs.
‘Existing ISDB-T chips without diversity are averaging about 90 to 100 mW in ISDB-T one seg,’ confirmed Koutras, and this will offer the same kind of performance, but with diversity. We reckon the diversity gives you about 3 dB better performance.’
3dB (decibels) means that in many cases, particularly in urban canyons (between high rise buildings where the only radio signals are bounced off walls), reception with two internal, one inch, UHF antennas, will be better than devices with external antennas.
‘We have tested these chips at 240 kilometers per hour (high Doppler) and with multipath effects in urban canyons, and there’s where we got the 3dB figure from,’ said Koutras.
MaxLinear is cagey about which markets it plans to go after next, and has only really just started on a design of ATSC M/H for the US. Instead it expects other parts of Asia to be its next rich pickings which either means that it plans to enter late into the T-DMB market in South Korea, where external antenna are still used on most devices, or to launch an attack on China with CMMB, or both. Potentially it could target DVB-H in places like Vietnam, Indonesia and the Philippines, but the shipment numbers are so low right now that this seems unlikely.
Right now MaxLinear has 35 customers which include Panasonic, Murata Manufacturing, MTC, Alps Electric, Mico and Sony and has so far cumulatively shipped 65 million RF receivers and RF receiver SoCs. It had net revenues of $36.1 million over the first nine months of 2009.
Other markets for MaxLinear include European DVB-T terrestrial broadcasting set tops, usually in products made by Chinese manufacturers and it plans to attack the market for cable set tops and is targeting Motorola, Cisco’s Scientific Atlanta arm, Arris and Thomson with tuner designs.
The new MaxLinear product is called the MxL751SM and it supports a tuning range of 470 MHz to 806 MHz and is available for sampling this quarter.