GainSpan, a Sunnyvale, Calif.-based innovator of Wi-Fi sensor network technology, has completed its Series B funding round, raising a total of $20 million. The round was led by Opus Capital with participation from returning investors Intel Capital, New Venture Partners, OVP Venture Partners and Sigma Partners. Opus General Partner Carl Showalter will join GainSpan's board of directors. www.gainspan.com