RF Micro deal is aimed at expanding its presence in WiMax, broadband, cable TV, and wireless infrastructure Mobile phone chip maker RF Micro Devices plans to buy Sirenza Microdevices in a $900 million deal aimed at expanding its presence in WiMax, broadband, cable TV, and wireless infrastructure.The deal is a sign that merger and acquisition activity in the technology sector is not over, despite credit industry problems that have roiled global stock markets.RF Micro, of Greensboro, North Carolina, will pay $300 million in cash and the rest in stock for Sirenza. Each outstanding share of Sirenza stock will be exchanged for 1.78 shares of RF Micro stock, as well as $5.56 in cash to close out the deal. The transaction is expected to be completed by Dec. 29 of this year, the companies said in a joint statement on Monday. The acquisition will reduce RF Micro’s dependence on the mobile phone market, said Stan Bruederle, an analyst at Gartner, in a report. RF Micro has been hurt this year by troubles at Motorola, a major handset customer that has faced declining revenue and profit in the face of stiff competition.“The acquisition of Sirenza reduces RFMD’s dependency on the mobile-handset market from 94 percent to 77 percent, bringing more stability to the company’s business and strengthening RFMD’s profits,” Bruederle wrote.Some Sirenza executives will move to North Carolina after the deal is completed to become part of RF Micro. Sirenza is located in Broomfield, Colorado. Bob Van Buskirk, the president and CEO of Sirenza, will lead RF Micro’s new Multi-Market Products Group, while Bob Bruggeworth, president and CEO of RF Micro will continue on in his current role of the combined company. Technology Industry