Wifi Antenna Performance

A project log for Small ESP32 Module for Easier Custom Design

Unhappy with the ESP32-WROOM module, I designed an ESP32 D2WD module to ease custom board assembly and enable small, wearable ESP32 devices

Kris WinerKris Winer 03/04/2018 at 19:420 Comments


I ran a simple wifi scan program as a test of the antenna performance and found the chip antenna quite disappointing. For the 1.2-inch wire antenna, I found the two wifi hotspots in my house (router and extender) at RSSI of -27 and -59 dB, on average, and about half the time I also detected the neighbor's wifi at -93 dB. With the ESP-WROOM dev board and its pcb antenna I did a little worse, finding the two in-house stations at -30 and -67 dB and once I also found the neighbors at -91 dB. Worst of the three was the chip antenna, which found both in-house hotspots at -38 and -71 dB and never saw the neighbors wifi. This is only a semi-quantitative result but it is clear that either the chip antenna is improperly designed (I guessed, after all) or the matching circuit is way off. I think this means short of a network vector analysis and pi match tuning, I am going back to the wire antenna solution...