• New GPS Antenna!

    Eric Sims05/18/2019 at 23:28 0 comments

    I wasn't too happy with the original GPS chip antenna I chose for this board (1575AT43A40). It was really convenient though. It has a gain of  -2.5 dBi and I was not too happy with the rf radiation pattern. (you can find the datasheet here: https://www.sparkfun.com/datasheets/GPS/JTI_Antenna-1575AT43A40_2006-09.pdf)

    So I switched to a different ceramic chip antenna, the W3011A. This has a gain of +1.0 dBi and a return loss of -16 dB, which is much better than the -9.5 dB from the old antenna. In addtion, it doesn't need as much clear area around it, so I can make the board a little more narrow.

    (datasheet here: https://www.mouser.com/datasheet/2/336/-13567.pdf)

    Also, here is a picture of the board layout for one of the 5 antennas + passives + LNAs. You can see the chip antenna in the upper right with the keepout layer to restrict the ground plane.