The cheap ESP8266 boards are offered on ebay with two built-in antenna options:
(PCB photographs see below.)
Has somebody bought both and compared their signal quality?
Or can somebody from looking a the desing hazard a guess how signal qualities will compare?
I've been playing with ESP01 and ESP03 and the ceramic antenna beats the PCB antenna by far.
While doing throughput tests I could not get the ESP01 to reliably get more than 1mbps until I touched the antenna with my hand (getting 10mbps). With the same program on the ESP03 the rate was always 10mbps.
Also with ESP01 I get 20-90ms of RTT in my home WLAN and with ESP03 I get a steady 2-3ms.
I'm definitely not an expert on this, but considering they put effort in building it with the ceramic antenna, I'm assuming that that version should be better somehow (because a PCB trace is much easier to produce).
I've been playing a little with the ESP8266 myself lately; with the PCB trace antenna. It's reception is extremely good. In a typical neighbourhood my smartphone (Sony XPeria M) sees eight networks; my laptop (Lenovo U410) six (bit disappointing really) but the ESP8266 leads with a whopping ten networks!
Of course, part of this is at what signal strength the device thinks the signal is poor enough to exclude it from the list. I think my laptop stops earlier because it relies on more internet traffic than my phone. The ESP may not have a threshold at all, I'm not sure.
In any case, I did some testing with putting many devices around the chip (oscilloscope, laptop downloading some data, phone downloading some data, ham transceiver) and the ESP8266 doesn't really seem to care. It still sees ten networks and the connection is about as fast.
So for normal operation I think you're fine with the PCB trace antenna. I didn't try putting the chip in a metal case though, so if you're going to demand a lot environment-wise from it, you may need the ceramic one.
