Non-linear high-frequency amplifier arrangement

Abstract

A non-linear high-frequency amplifier arrangement suitable for generating power outputs >1kW at frequencies of >1MHz for plasma excitation is provided. The arrangement includes two LDMOS transistors each connected by their source connection to aground connection point, where the LDMOS transistors have the same design and are arranged in an assembly, a power transformer whose primary winding is connected to drain connections of the LDMOS transistors, a signal transformer whose secondary winding is connected by a first end to a gate connection of one LDMOS transistor and by a second end to a gate connection of the other LDMOS transistor, and a feedback path from the drain connection to the gate connection of each of the LDMOS transistors.

What is claimed is: 
     
         1 . A high-frequency amplifier arrangement for generating an output power of >1 kW at frequencies of >1 MHz for plasma excitation, the high-frequency amplifier arrangement comprising:
 a. first and second Laterally Diffused Metal Oxide Semiconductor (LDMOS) transistors, wherein each is connected to a ground connection point by their respective source terminals, and wherein the LDMOS transistors are embodied alike and are arranged in a package;   b. a power transformer, a primary winding of which is connected to drain terminals of the LDMOS transistors;   c. a signal transformer, a secondary winding of which is connected at a first end to a gate terminal of the first LDMOS transistor and at a second end to a gate terminal of the second LDMOS transistor; and   d. a first feedback path from the drain terminal of the first LDMOS transistor to the gate terminal of the first LDMOS transistor and a second feedback path from the drain terminal of the second LDMOS transistor to the gate terminal of the second LDMOS transistor.   
     
     
         2 . The high-frequency amplifier arrangement of  claim 1 , wherein each of the first and second feedback paths comprises a respective series circuit including a respective resistor and a respective capacitor. 
     
     
         3 . The high-frequency amplifier arrangement of  claim 2 , wherein each of the respective resistors has a resistance value in a range from 200 ohm to 600 ohm, and each of the respective capacitors has a capacitance in a range from 0.5 nF to 5.0 nF. 
     
     
         4 . The high-frequency amplifier arrangement of  claim 1 , wherein the secondary winding of the signal transformer is connected at the first end to the gate terminal of the first LDMOS transistor by one or more first resistive elements and is connected at the second end to the gate terminal of the second LDMOS transistor by one or more second resistive elements, such that a lossy gate circuit is produced. 
     
     
         5 . The high-frequency amplifier arrangement of  claim 4 , wherein each of the resistive elements is configured as a resistor having a resistance value in a range from 1 ohm to 100 ohm. 
     
     
         6 . The high-frequency amplifier arrangement of  claim 1 , wherein the drain terminals of the LDMOS transistors are respectively connected to ground by at least one capacitor. 
     
     
         7 . The high-frequency amplifier arrangement of  claim 6 , wherein the capacitors are connected to ground by one of a plurality of parallel vias and through-plating into a heat spreader of the LDMOS transistors. 
     
     
         8 . The high-frequency amplifier arrangement of  claim 1 , further comprising a circuit board that lies flat on a metal cooling plate and is connected to the cooling plate. 
     
     
         9 . The high-frequency amplifier arrangement of  claim 8 , wherein the circuit board is connected to the metal cooling plate by a plurality of ground connections, and the metal cooling plate is connected to ground. 
     
     
         10 . The high-frequency amplifier arrangement of  claim 8 , wherein the package is arranged on the circuit board. 
     
     
         11 . The high-frequency amplifier arrangement of  claim 1 , wherein a primary winding of the signal transformer is connected to a high-frequency input, and a secondary winding of the power transformer is connected to a high-frequency output.