Peter Neufeld Boosts the Espressif ESP32-C3 "SuperMini" Module's Wi-Fi Range — with a Bit of Wire

Maker Peter Neufeld has demonstrated how to boost the range of Espressif ESP32-C3-based SuperMini development boards' wireless connectivity — with a carefully-sized piece of bent wire.

"The [Espressif] ESP32-C3 SuperMini modules are incredibly affordable, costing around €2 (around $2.20), and are equipped with a compact SMD [Surface Mount Device] antenna," Neufeld explains. "However, this tiny antenna significantly limits the usable Wi-Fi range due to its design. To address this issue with minimal effort, I implemented a simple antenna modification that drastically improved performance."

When Neufeld says "simple," he's not over-egging the pudding: the modification needs nothing more than a piece of wire, cut to a very specific length. "This modification involves adding a 31mm length of 1.0mm silver-plated wire, configured as a quarter-wavelength (λ/4) antenna," Neufeld explains. "The bottom section of the wire is bent into a horizontal loop (approximately 16mm of the wire length, forming a loop with a diameter of about 8mm), while the remaining section is angled vertically upwards."

The loop portion is then opened enough to clip onto either end of the on-board chip antenna, which should be left in place. Solder either end, and you've effectively made a bypass — resulting in the wire antenna being used in favor of the SMD antenna fitted at the factory.

"On average, the improvement in signal strength was at least approximately 6dB," Neufeld says of his testing. "In many cases, particularly at the edges of the Wi-Fi signal range or in environments with more interference, the improvement even exceeded 10dB. This difference in signal strength had a significant impact on the stability of the connection. The modified module maintained a stable connection while the unmodified module was more prone to disconnections or performance degradation."

Neufeld's full write-up is available on his website, along with an ANNEX32 BASIC program for signal strength testing.