How do I do a push-push port?

Geometry Elements - Ports

All ports with the same number are electrically connected together. As many physical ports as desired may be given the same numeric label. Such ports are sometimes called ”even-mode” or ”push-push” ports and have many uses, including the even-mode response of a circuit.

For a detailed discussion with more detail on how an even mode port is modeled in Sonnet, see Using Even and Odd Mode Parameters.

For a procedure which details how to set up ports with the same numbers, see How do I do a push-pull port?