v0.1: Antenna should be covered in solder mask
al177 opened this issue · 1 comments
The PCB trace inverted F antenna KiCad library has no solder mask on top of the antenna. Per the TI DN007 appnote describing the design, the thickness should be 1oz copper. Without soldermask the antenna is covered in plating, increasing the thickness beyond the 1oz copper layer. Additionally, the mask protects from direct contact with other metal objects. The appnote does not specifically mention putting mask over the antenna, but the example photos show green mask over the antenna.
The antenna performance is decent on the v0.1 protos, which may be due to a consistent ENIG finish used by the board house. But if the board were to be built using HASL the thickness and consistency may change enough to detune the antenna.
Fix is to clone the symbol to the project library and add a mask.
Fixed in v0.2. Updated the antenna part to put mask on all the copper traces.