ESP8266 Community Forum

- Wed Sep 17, 2014 3:13 am #691 Digikey , they have 3k on stock. around $1 each. For the breakout I have to order from DK anyway.

The nice thing on that antenna is that i don't have to adjust the groundplane. For the other chip antennas or pcb antennas you need a fairly large keep out area around the antenna.

- Wed Sep 17, 2014 9:28 am #695 Mar has Masters from MIT in radio design. I don't believe the Econotag is FCC approved. There is a loophole that lets him ship if there is no firmware installed. Until there is firmware FCC does not classify it as a radio. The end user then installs the firmware under FCC experimental rules. I picked it because the design is open.

He has other product that he sells. They have full FCC approval. He has all kinds of fancy spectrum analyzers and a network analyzer to work on antennas. I suspect those issues you see don't have any real effect on the antenna performance or he would fix them.

Where I get my modules

- Wed Sep 17, 2014 9:34 am #697 To hook up the spectrum analyzer he saws the PCBs up in to pieces and then tests the pieces. Econotag was designed to be very low cost at the time it was designed. Design is 6-7 years old now. His more expensive stuff has antenna jacks on it.

Where I get my modules

- Wed Sep 17, 2014 9:48 am #698 Poke around on the chip sites, there are lots of excellent app notes on how to make PCB antennas. Mar's opinion is that chip antennas aren't any better than PCB ones, they are just smaller and are often much worse than a PCB antenna. They only make sense when you are space constrained.

http://www.ti.com/lit/an/swra117d/swra117d.pdf
http://www.ti.com/lit/an/swru120b/swru120b.pdf
http://www.ti.com/lit/an/swra350/swra350.pdf

http://fabiobaltieri.com/2012/05/06/2-4 ... e-library/

The real art with antennas is making them disappear by turning the case into the antenna or some other part. For example the stick-n-find, https://www.sticknfind.com/, is an excellent example of this. Inside of it there is a simple metal disk that sits on top of three metal supports on the PCB. That disk does three things - it is a speaker, it is a mic, and it is the antenna.

Where I get my modules