Combiner/splitter

A circuitry comprising:

• a first trifilar transformer having a first outer transmission element electrically coupled between a first port node and a first intermediate node;
• a second trifilar transformer having a second outer transmission element electrically coupled between the first intermediate node and a second port node;
• a third trifilar transformer having a third outer transmission element electrically coupled between the first port node and a second intermediate node;
• and
• a fourth trifilar transformer having a fourth outer transmission element electrically coupled between the second intermediate node and a third port node, wherein the second port node and the third port node are different nodes through which different signals from different external sources can be received, and the first trifilar transformer, the second trifilar transformer, the third trifilar transformer, and the fourth trifilar transformer are fabricated from metal layers and integrated into an integrated circuit die.

A method of combining or splitting radio frequency (RF) signals using circuitry having a first port node, a second port node, and a third port node, the method comprising:

• routing an RF signal between the first port node and the second port node via a first signal path comprising a first trifilar transformer and a second trifilar transformer;
• and
• routing an RF signal between the first port node and the third port node via a second signal path comprising a third trifilar transformer and a fourth trifilar transformer,
• wherein the first, second, third, and fourth trifilar transformers are configured to provide an overall insertion loss of no more than 0.3 dB from 28 GHz to 32 GHz.

A method of operating a wireless communication device, the method comprising:

• receiving, at one or more antennas, an RF signal;
• routing the RF signal through antenna switching circuitry to a circuitry;
• and
• splitting or combining the RF signal using the circuitry, wherein the circuitry comprises:
• a first trifilar transformer having a first outer transmission element electrically coupled between a first port node and a first intermediate node;
• a second trifilar transformer having a second outer transmission element electrically coupled between the first intermediate node and a second port node;
• a third trifilar transformer having a third outer transmission element electrically coupled between the first port node and a second intermediate node;
• and
• a fourth trifilar transformer having a fourth outer transmission element electrically coupled between the second intermediate node and a third port node.