Hi,
nRF9151 + Kyocera AVX P822601 internal SMT antenna: 8 dB RSRP loss vs external antenna — possible PCB layout issue?
Test Results
Test 1 — Out of Faraday cage, internal P822601 antenna:
WR-2370 CONNECTED — RSRP: -66 dBm, RSRQ: -5 dB
Test 2 — Out of Faraday cage, external Taoglas FXUB65.07.0180C via SMA:
WR-XXX-2149 CONNECTED — RSRP: -65 dBm, RSRQ: -6 dB
Test 3 — Inside Faraday cage, internal P822601 antenna:
WR-2370 FAILED — no message received
Test 4 — Inside Faraday cage, external Taoglas FXUB65.07.0180C:
WR-XXX-2149 CONNECTED — RSRP: -65 dBm, RSRQ: -6 dB
Reference device for comparison:
WR-8738 (Taoglas FXUB65 external) CONNECTED — RSRP: -58 dBm, RSRQ: -5 dB
Summary of Issue
- Approximately 8 dBm RSRP difference between internal P822601 and external Taoglas FXUB65 antenna
- External antenna works reliably inside Faraday cage
- Internal antenna completely fails inside Faraday cage
- Both devices use the same nRF9151 SiP and same firmware
- RF switch configuration confirmed:
- R42 = DNP
- R43 = 0Ω (internal antenna path active)
We designed the RF layout same as the Nordic nRF9151 DK board reference design.
https://devzone.nordicsemi.com/support/348377
Attached Files:
- Schematic (RF section)
- PCB layout
drive.google.com/.../1tCCkOSTPwavuZT4Ztj6aebqibDN27iHo
Thank you for your support. We look forward to your guidance and hope you can help us resolve this issue.