A syndicate of strategic and financial investors participated. India's Reliance Technology Ventures Ltd. led the deal, which included previous investors ADC Telecommunications of Eden Prairie, Minn., Express Ventures of San Diego, Hercules Technology Growth Capital Inc. of Palo Alto, Calif., Investec of South Africa and an unnamed wireless carrier.

The deal comes on top of $3.2 million in Series A investment in 2006, and it is expected to take the company to profitability in 2009.

E-Band co-founder and vice president of marketing Saul Umbrasus said the company was formed with angel funding in 2003 with an eye to the opening up of new wireless spectrum for extremely fast, high-capacity point-to-point wireless transmission, but the company did not raise development money until the U.S. Federal Communications Commission authorized opening of the 70/80 GHz millimeter-wave spectrum in 2005.

As part of its early development, E-Band contracted with Northrop Grumman Corp. for proprietary gallium arsenide semiconductors for use in its transmission equipment, which allowed the company to accelerate development after the spectrum was opened.

Umbrasus said E-Band's equipment allows carriers and enterprises to transmit gigabits of bandwidth over the air to satisfy numerous high-speed broadband network and access applications. The equipment is used by carriers and enterprises to replace physical fiber optic lines, which typically require expensive installation and are widely used in backhaul systems to sell sites by wireless carriers and by universities, hospitals and corporate campuses for enterprise networks.

Umbrasus said the company operates in an area that only recently could be served by wireless technology, allowing potential customers to expand coverage that would be much more expensive using fiber optic cable. The sector has drawn much interest from investors and startups serving the carrier market, and last month, Seattle-based Telecom Transport Management Inc. raised $120 million in a venture investment to build out backhaul networks for cellular carriers in several U.S. markets using wireless equipment similar to E-Band's.

Umbrasus said the company had initiated some fundraising discussions when it was approached by Reliance Technology Ventures, the corporate venture capital arm of the Indian conglomerate Reliance ADA Group.

"ADA was the best of both worlds, with the financial resources behind it and as a major customer," Umbrasus said. "The team at E-Band Communications Corp. is delighted to have the support of such a world-class group of investors."

E-Band used no outside financial adviser for the round. It had legal work on the deal from Jeffrey Higgins of Gunderson Dettmer Stough Villeneuve Franklin & Hachigian LLP in San Diego. Latham & Watkins LLP, also in San Diego, represented investors.