Engim Inc., a fabless silicon design start-up that has designed a chipset to boost the capacity of wireless LAN (WLAN) access points by up to 50 times, has raised US$18.5 million in a second round of equity financing.

The Acton, Mass., company recently started sampling its chipset and apparently, investors liked what they saw.

The latest cash infusion came from Engim’s existing investors, Matrix Partners and Bessemer Venture Partners, plus two new ones, Benchmark Capital, which led the latest round, and Adams Street Partners. First round funding in late 2001 netted US$16 million.

Money from the second round funding will be used to integrate the Engim chipset with WLAN access points, and to expand the chip technology into unnamed new markets and applications.

Engim’s silicon can “see” and manipulate all possible WLAN channels in the WLAN radio spectrum. Sophisticated signal processing technologies wring out what is otherwise inherent radio interference between these channels. By doing so, the chipset lets access points broadcast at the same time on multiple channels, boosting WLAN throughput and range.

In June, Engim hired as CEO Nick Finamore, a former general manager of Intel’s network processor division. Several integrated circuit design experts from the Massachusetts Institute of Technology, Motorola Inc. and Texas Instruments Inc. founded Engim in January 2001.