Radio Frequency (RF) & Wireless Design

I have modeled some of the I-PEX connectors in the past up to 6 GHz for Wi-Fi and for cellular applications, but came across this article for the latest I-PEX connectors that are good to 9 GHz :

https://www.everythingrf.com/news/details/12932-i-pex-micro-coaxial-cable-connectors-small-form-factor-with-big-performance-up-to-9-ghz

What's important to understand from this is that even if you don't need beyond the 6 GHz in your application, the ability to reduce losses from connectors and cables (and coax has extremely high loss, especially the smaller diameter versions).

As a rule of thumb, if you want to reduce coax losses to reduce power output and improve sensitivity to receivers, larger diameter coaxes are better since they have lower losses. Use of double braids can also improve noise rejection.

But in mind that overall the best way to lower losses is just simply use the absolute minimum amount of coaxial cable.