Recent years, HARRIS and MAR in USA, PHILIPS in HOLLAND, THOMSON in FRANCE and TOSHIBA, NEC in Japan have been doing efforts in researching and exploiting of new material and new kinds of transistor amplifier and have offered varieties of schemes.

• 近年来，美国的HARRIS和MAR、荷兰的PHILIPS、法国的THOMSON、日本的TOSHIBA和NEC等公司都在不断地致力于新材料和新型晶体管放大器件的研制开发，并提供各种应用解决方案。