US Patent 9634619 Power amplifier bias circuit having parallel emitter follower

Improved power amplifier (PA) bias circuit having parallel emitter follower. In some embodiments, a bias circuit for a PA can include a first bias path implemented to couple a base node of an amplifying transistor and a supply node, with the first bias path being configured to provide a base bias current to the base node. The PA can further include a second bias path implemented to be electrically parallel with the first bias path between the base node and the supply node. The second bias path can be configured to provide an additional base bias current to the base node under a selected condition.