One of the reasons why Broadcom has mounted its eye-watering bid for Qualcomm now is, of course, that the US firm’s value has been declining, hit by competitive challenges and, in particular, by the legal disputes with Apple. Most legal or antitrust battles do not have a direct, short term impact on quarterly results, but instead meander through appeals processes and endless compromises. But Qualcomm has been hit by two disputes which have shaken its usually solid financial performance. First, there was the Chinese probe of its business practices, which led to a large settlement and a permanent reduction in royalty rates in the country. That onerous agreement was nevertheless better than prolonging the pain of seeing royalties withheld by…