Push-pull class E amplifier

A push-pull class E amplifier, comprising:

• an input configured for receiving a signal to be amplified;
• an output configured for outputting the signal after amplification;
• a printed circuit board having a first dielectric layer and a second dielectric layer;
• a first amplifying unit having a first input and a first output;
• a second amplifying unit having a second input and a second output, the first and second amplifying unit being configured to operate in class E;
• a balun having an unbalanced port connected to the input, and a first balanced port connected to the first input and a second balanced port connected to the second input;
• a capacitive unit comprising a capacitor coupled between the first output and ground and a capacitor between the second output and ground, or a capacitor coupled between the first and second outputs;
• a first line segment having a first end and a second end, the first end of the first line segment being coupled to the first output;
• a second line segment having a first end and a second end, the first end of the second line segment being coupled to the second output, and the second ends of the first and second line segments being connected to each other, the first and second line segments and the capacitive unit forming part of a class E matching network for the first and second amplifying units;
• wherein the first line segment and the second line segment are arranged on the first dielectric layer;
• the push-pull class E amplifier further comprising:
• a third line segment arranged in between the first and second dielectric layers and having a first and second end, wherein the first end is connected to ground;
• a fourth line segment arranged on the second dielectric layer on a side facing away from the first dielectric layer and having a first end and a second end, the first end of the fourth line segment being connected to the second end of the third line segment through a via extending through the second dielectric layer, and the second end of the fourth line segment being connected to the amplifier output;
• wherein a combined length of the third line segment and the fourth line segment corresponds to a quarter wavelength at a frequency lying within an operational frequency range of the amplifier;
• wherein the first and second line segments form a first loop;
• wherein the third line segment forms a second loop comprising m turns;
• wherein the fourth line segment forms a third loop comprising n turns;
• wherein a length of the first line segment and a length of the second line segment each corresponds to an eighth of a wavelength divided by (n+m) at the frequency lying within the operational frequency range of the amplifier;
• wherein the first line segment, second line segment, and the third line segment are formed using coupled transmission lines;
• and
• wherein the third line segment and the fourth line segment are formed using coupled transmission lines.