Improved GPS reception with a ground plane
My poor-man’s 10 MHz reference based on the Ublox Neo-7M GPS module didn’t always receive GPS satellites reliably enough. Since I rely on reception indoors, conditions were sometimes too marginal to lock the oscillator output to 10 MHz. Inspired by the QRPlabs GPS module of Hans Summers (G0UPL) with its large 6 x 6 cm PCB groundplane, I therefore decided to do something similar.
It definitely helped make indoors reception in my shack much more reliable. The first picture shows the unit with the 8.5 x 6.5 cm single-sided PCB ground plane attached with double-sided tape. The picture below shows it prior to adding the ground plane. I also added a small LED to the right so that I could see from the outside whether the GPS locks properly.
This post is a continuation of these other posts about the 10 MHz reference:
- Just good enough 10 MHz reference (3 Oct 2015)
- Better with SMA (15 Oct 2015)
- Curing amnesia in the 10 MHz GPS reference (19 Nov 2015)
Ublox has a good application note regarding different GPS antennas which addresses patch antennas and ground plane size. A significant gain is realized with ground planes approaching 70mm sq. (and larger)
https://www.u-blox.com/sites/default/files/products/documents/GPS-Antenna_AppNote_%28GPS-X-08014%29.pdf?utm_source=en%2Fimages%2Fdownloads%2FProduct_Docs%2FGPS_Antennas_ApplicationNote%28GPS-X-08014%29.pdf