Change has been in the air at RPX Corp., the San Francisco-based defensive patent aggregator.

Three new members have joined RPX's board of directors in the last year. Founder and CEO John Amster resigned in February after he and the board reached impasse on Amster's plan for a private sale. General counsel Marty Roberts was promoted to CEO. Andy Block and Neal Rubin joined as senior vice presidents from Time Warner Cable and Cisco Systems Inc., respectively.

Then last week Mallun Yen announced that she is moving on from her executive vice president role in September. Yen is a former intellectual property chief at Cisco who worked with RPX from its 2008 inception as a client and then formally came aboard in 2010. But Yen isn't leaving RPX altogether. She too is taking a position on RPX's board of directors.