Chip (ceramic) antenna superior to basic wifi dipole.

[MMliam]

Controlled tests comparing a chip (ceramic) antenna to a basic wifi dipole with ESP8266 modules, demonstrated a commensurate transmission distance under varying weather conditions with the chip-antenna. The judged superiority of the ceramic antenna is do to the diminutive size of ceramic antenna as compared to the dipole.

I have only found ESP8266 modules with the chip-antenna.
I have been unable to find ANY ESP32 modules with the chip-antenna.

The chip-antenna has several advantages over a basic dipole; smaller, and no losses with higher frequency. Chip-antennas are particularly more efficient than the typical meandered-inverted-F antenna utilized on most modules.
This begs the question; why aren't there any ESP32 modules that utilize the ceramic chip-antenna?
And, does Espressif have any plans to address this apparent oversight?

[ESP_Sprite]

Do you have a source for this information? Asking because from what I read, a meandered-F, when implemented correctly, is actually the better antenna in all aspects but size.

[MMliam]

My source is the controlled tests I ran comparing meandered inverted-F, half-wave dipole, and the ceramic chip antenna.

The ceramic chip antenna and dipole providing equivalent transmission distance performance. However, the ceramic chip antenna is less that 1cm. The meandered inverted-F does not come close to the performance of either the dipole or the chip. The meandered invered-F only connects at less than half the distance of the dipole & chip, and the meandered inverted-F does not have an omni-directional toroidal pattern as both the dipole & chip have.

The tests were run using the ESPNow protocol. The receiver station had a dipole, and two senders were used, one with a dipole and the other with the chip antenna. If a message sent was acknowledged by the receiver, the sender would flash it's led; effectively determining communication distance.

The same test was performed using a sender with a meandered inverted-F antenna. The meandered inverted-F unit achieved less than half the distance of the dipole, or chip units, and also suffered from erratic performance due to the lack of an omni-directional pattern.

[WiFive]

Can you give more details about the hardware used? There are a lot of third party modules and boards I wouldn't really trust the matching and impedance control and coupling of the pcb antenna.

[MMliam]

I've used D1 Mini Pro modules and ESP-07 modules (in a programming fixture) both types with the same results. These modules are offered by many sellers, but there is no indication as to what company is the actual manufacturer.

I've also used numerous ESP versions (01S, 12E&F, 32) with a meandered inverted-F antenna, and ESP-32u with half-wave dipole antenna.

MM

[WiFive]

You may consider trying an official espressif development board to test pcb antenna performance which uses an espressif module that is mounted properly with the antenna sticking off the board.