Patent ID: 7221228

Claim:
A radio frequency power amplifier module comprising: a first transistor to amplify a signal inputted through an input or inter-stage impedance matching circuit and output a first amplified signal; a second transistor to amplify the first amplified signal inputted through an output terminal of said first transistor and output a second amplified signal to and output impedance matching circuit; a first terminal to supply a driving voltage to an output terminal of said second transistor; a first interconnection to couple said first terminal and the output terminal of said second transistor; a second terminal to supply current to an input terminal of said first transistor; a second interconnection to couple said second terminal and the input terminal of said first transistor; a first through hole, provided on a first dielectric plate for electrically connecting said second interconnection and second terminal; a second through hole, provided on the first dielectric plate for electrically connecting said first interconnection and the output terminal of said second transistor; a third through hole, provided on a second dielectric plate for electrically connecting said second interconnection and second terminal; a fourth through hole, provided on the second dielectric plate for electrically connecting said first interconnection and the output terminal of said second transistor; a first ground part An electromagnetic shielding being mounted on a back side of said second dielectric plate and provided between said first terminal and second terminal; a second ground part for electromagnetic shielding being mounted on main front side of said first dielectric plate and provided between said first through hole and said second through hole; and a third ground part for electromagnetic shielding being mounted on main front side of said second dielectric plate and provided between said third through hole and said fourth through hole, wherein at least a through hole is provided on a region of a third dielectric plate on whose back side said second ground part for electromagnetic shielding is mounted, and wherein said input or inter-stage impedance matching circuit and said output impedance matching circuit are formed above the region of the third dielectric plate.