Patent ID: 7551036

Claim:
A power amplifier for amplifying high frequency (HF) signals comprising: several amplifier elements (T_ 1 , . . . , T_ 4 ) each with an amplifier channel (DS) and a gate terminal (G) for controlling the amplifier channel (DS), whereby the amplifier channels (DS) of the amplifier elements (T_ 1 , . . . , T_ 4 ) are connected in series; a supply voltage (U_d) for the amplifier elements (T_ 1 , . . . , T_ 4 ) that is applied to the serial connection; a selectable potential (U_g) that is present at the gate terminal (G) of the first amplifier element (T_ 1 ) of the serial connection; an HF input ( 2 ) that is connected to the gate terminal (G) of the first amplifier element (T_ 1 ) of the serial connection via a first adjustment network ( 3 ); an HF output ( 5 ) that is connected to a drain (D) of the last amplifier element (T_ 4 ) of the serial connection via a second adjustment network ( 6 ); at least one capacitor (C_ 2 , . . . , C_ 4 ) connected to ground potential, each at the gate terminal (G) of the second amplifier element (T_ 2 ) and to the last amplifier element (T_ 4 ); and at least one resistor (R_ 2 , . . . , R_ 4 ), each between the gate terminals (G) of adjacent amplifier elements (T_ 1 , T_ 2 ; T_ 2 , T_ 3 ; T_ 3 , T_ 4 ), at least one resistor (R_ 5 ) between the gate terminal (G) and the drain terminal (D) of the last amplifier element (T_ 4 ), characterized by at least one limiting path ( 7 ) that is connected between the drain terminal (D) and the gate terminal (G) of at least one amplifier element of the serial connection from the first amplifier element (T_ 1 ) to the next to the last amplifier element (T_ 3 ), whereby the limiting path ( 7 ) can be toggled between a conducting state and a blocking state corresponding to a voltage (U — GD ) that is present between the drain terminal (D) and the gate terminal (G) of the amplifier elements (T_ 1 , . . . , T_ 3 ).