Microtune Inc. (Nasdaq: TUNE) has developed a silicon tuner that will enable cable operators to offer broadband speeds of 160 Mbit/s or more, catching up with cable chip rivals Broadcom Corp. (Nasdaq: BRCM), Conexant Systems Inc. (Nasdaq: CNXT), and STMicroelectronics NV (NYSE: STM).

The new Microtune silicon-based tuner for cable modems and digital set-top boxes is designed to support channel bonding, a key part of the new Docsis 3.0 specification. As the latest Cable Television Laboratories Inc. (CableLabs) Docsis spec calls for, the new tuner chip can handle the bonding of at least four virtually linked channels to boost broadband bandwidth and data downstream speeds as high as 160 Mbit/s or more.

Company officials say the new wideband tuner, known as the MT2170, offers the same functionality as four discrete Docsis 2.0 tuners inside today's cable modems. As a result, they say, it will cut the physical size, cost, and power consumption of the tuners in those modems by about 75 percent.

Microtune executives also boast that their new chip exceeds Docsis 3.0 requirements by enabling cable operators to bond various 6MHz channels within a 100Mhz range, providing them with greater flexibility for tapping spectrum slices. The 3.0 spec sets a minimum spectrum range of 64 MHz for the bonded channels.

Plus, company officials say the new silicon tuner can receive and tune radio frequencies in the range of 50 MHz to 1 GHz, even though today's cable systems only go as high as 750 to 860 MHz. With a number of major cable tech vendors now pushing cable plant and equipment upgrades to 1 GHz to gain more RF spectrum, including at least 20 more 6MHz channels, several major MSOs are quietly considering such a move.

"We're the first to come out with a 1GHz tuner," says Microtune CEO Jim Fontaine. "We hope we're a bit ahead of the pack."

Like Broadcom, Conexant, and STMicroelectronics, Microtune is betting that there will be strong, early MSO demand for Docsis 3.0 cable modems. Although CableLabs is still putting the finishing touches on the spec, Fontaine thinks that cable modem tuner manufacturers will be shipping "a couple of million" tuners for wideband modems by the end of next year and about 5 million in 2009.

"The Comcast Corp. (Nasdaq: CMCSA, CMCSK) guys say it'll happen even faster than that," he notes.

Industry analysts agree that there's growing cable interest in wideband modems as rival telcos like Verizon Communications Inc. (NYSE: VZ) roll out fiber-to-the-premises (FTTP) networks. "There's no market yet because there's no product yet," says Mike Paxton, a principal analyst at In-Stat . But, he notes, "there's interest from the cable operators to have at least pre-3.0 and 3.0 products available."

With its new silicon tuner, Microtune will largely do battle with Broadcom. Microtune, which recently announced that it had shipped its 50 millionth silicon tuner, mainly makes the devices for Scientific Atlanta modems and set-tops and Arris Group Inc. (Nasdaq: ARRS) embedded multimedia terminal adapters (E-MTAs). Broadcom mostly produces silicon for cable modem leader Motorola Inc. (NYSE: MOT), while Conexant and STMicroelectronics concentrate more on chipsets for modems and set-tops.

Microtune, which also works closely with Texas Instruments Inc. (NYSE: TXN), says it has started sampling the new tuner to undisclosed "leading technology developers." The company plans to extend samples to "select customers" over the spring. It's pricing the tuner at less than $5 a unit in "volume quantities."

— Alan Breznick, Site Editor, Cable Digital News