Balun transformer with improved harmonic suppression

An electronic assembly comprising:

• a substrate;
• a balun transformer formed on the substrate and comprising a first winding and a second winding, each of the first and second windings having respective first and second ends;
• an antenna formed on the substrate and electrically coupled to the first end of the first winding of the balun transformer;
• a ground terminal on the substrate and electrically coupled to the second end of the first winding of the balun transformer;
• an amplifier electrically coupled to the first end of the first winding of the balun transformer;
• and
• a reaction circuit component formed on the substrate and electrically coupled to the second winding between the first and second ends thereof, wherein the balun transformer and the reaction circuit component jointly form a harmonically suppressed balun transformer having a fundamental frequency and wherein the reaction circuit component is tuned such that the harmonically suppressed balun transformer resonates at a selected harmonic of the fundamental frequency.

A method for forming an electronic assembly comprising:

• forming a first winding on a substrate, the first winding having first and second ends;
• forming a second winding on the substrate, the second winding having first and second ends, the first and second windings jointly forming a balun transformer;
• forming a reaction circuit component on the substrate, the reaction circuit component being electrically coupled to the second winding between the first and second ends thereof;
• tuning the reaction circuit component such that the balun transformer and the reaction circuit component jointly form a harmonically suppressed balun transformer having a fundamental frequency and that resonates at a selected harmonic of the frequency;
• and
• forming an antenna on the substrate, the antenna being electrically coupled to the first end of the first winding,
• wherein the reaction circuit component comprises a capacitor and the selected harmonic frequency is a second harmonic of the fundamental frequency.