Vista, California-based Pacific Microwave Research, a developer of analog and digital microwave video transmission technology, has been acquired by Visilink plc, a Masachusetts-based firm. Visilink plc did not disclose financial terms of the deal. Pacific Microwave Research provides products used for covert surveillance, unmanned and aerial vehicle control, and evidence collection by the law enforcement, homeland security, and military. Visilink plc said the acquisition would "significantly" enhance its product offerings for law enforcement and security markets.