JRC's linear power amplifier for mobile transceivers evolved to have SAFF (Self Adjusting Feed Forward), and has further evolved to have high speed FF (Feed Forward), and DPD (Digital Pre-Distortion). This amplifier also has come to have low electricity consumption, small size, and low price. In addition, these amplifiers have become self adjusting and have achieved dramatically higher productivity. On the other hand, with the emergence of a new generation of power devices, the structure of amplifiers has evolved from parallel configurations to the Doherty type, and their efficiency has continued to improve. We here introduce these evolutions in technology, and lastly describe current efforts to make further improvements.