The Dropout's Guide to PCB Trace Antenna Design – Colin Karpfinger
Feature Request] Change the orientation of the ESP32 module/antenna so WiFi signal will interfere less with Zigbee · Issue #2 · fairecasoimeme/ZiGate-Ethernet · GitHub
The Many Ways You Can Easily Ruin Your PCB Antenna Design | Hackaday
ESP8266EX ceramic antenna design - Project Guidance - Arduino Forum
PCB antenna design problem: too short range? - Nordic Q&A - Nordic DevZone - Nordic DevZone