Microtune Amplifies Set-Top Strategy

Moving ahead with a digital set-top component strategy it began last August, Microtune Inc. last week introduced a trio of broadband amplifier chips targeted for forthcoming OpenCable-based boxes.

Those three pieces of silicon — the MT1230 IF (intermediate-frequency) Amplifier, MT1535 Upstream Amplifier and the MT1110 RF (radio-frequency) Broadband Amplifier — function as RF companion components to Microtune's family of broadband tuners.

Though each chip targets a different area, all three can be used to amplify signals that will flow through OpenCable set-tops without simultaneously boosting noise — a situation more commonly referred to as the signal-to-noise ratio, explained company president Jim Fontaine.

Strengthening that signal becomes extremely important in a digital environment, especially if cable customers continue to split signals to other devices, he said. That's because if a digital signal becomes too weak, it falls over a so-called digital cliff, resulting in total picture loss.

When an analog signal is weakened, it becomes riddled with snow. Though such a picture may be annoyingly difficult to see, it's not totally lost.

Balancing the signal-to-noise ratio under OpenCable specifications is tricky at best, since cable infrastructure was not originally designed for bidirectional video and data channels, Fontaine said.

"You need to make sure you don't add too much noise in order to keep the picture strong. It's difficult to amplify the signal without adding more distortions," he added.

OpenCable requires all three of Microtune's component types, but the company is willing to sell them individually. The MT1535 is currently available, while the MT1110 RF and IF amplifiers are due out later this quarter.

Microtune believes the fact that all three of its chips work together — and come from the same vendor — will help it to gain customers.

Fontaine agreed that it's difficult to break into the set-top box sector. Presently, Microtune sells RF products to three manufacturers outside of the Scientific-Atlanta Inc.-Motorola Broadband Communications Sector duopoly: Sony Corp. of America (tuner for data), Pace Micro Technology plc (upstream amplifier) and DIC Information Technologies Co. (tuner).

In addition to making products for set-tops and cable-modems, Microtune also plans to target the cable-telephony equipment sphere. Operators are continuing to explore second-line voice services using Internet protocol, Fontaine said.

The company appears to have a bit of a head start in that area. Microtune already has started to ship its tuners and upstream amplifiers for a Cisco Systems Inc.-built product based on Data Over Cable Service Interface Specification version 1.1.