IMP003 FCC-CA WiFi Capacitor

Hardware
1

My first prototype IMP003 design has been assembled and is in the post. Woo hoo!

While waiting for it to arrive I re-reviewed the design requirements and specifications of some of the components (first mistake) and found the WiFi capacitor (C14, CL05C100CB5NCNC) identified in the impee-fcc003-ca-bom.xls is a general purpose capacitor which surprised me somewhat as I don’t think this spec is suitable for reliable high frequency operation. Shouldn’t C14 be a high Q capacitor, like the Amy Dev Board C20 (GJM1555C1HR30BB01)? I imagine a suitable spec for the FCC-CA C14 would be GJM1555C1H100GB01D (I couldn’t work out how to specify a Samsung high Q cap using the MLCC product guide).

Am I way off or is the FCC-CA C14 spec incorrect?

2

The FCC tests were done with the component in the BOM, so it’s recommended you use that one (which is cheaper anyway).

imp005 confusingly also has a non-high-Q cap actually within the antenna structure, but that’s what the antenna engineers insisted on…

3

No worries, thanks Hugo.