Other Parts Discussed in Thread: FDC2112
Hello,
we are using FDC2112 on our module along with GNSS receiver (in combination with chip antenna). The chip antenna is 15 mm away from the FDC LC tank.
During GNSS testing on our module, we found we have a very large interference (relatively large, from GNSS perspective). So we did some measurements at the GNSS antenna with active probe and LNA, and found that antenna sees harmonics from FDC LC tank (we measure frequency at LC tank about 4.5 MHz and it looks very similar to the sine wave) at 1575 MHz. Those are cca 300th harmonics, and we measure them at the level of about -100 dBm (about 25dBm above noise floor). This usualy isn't some significant interference for the rest of the circuitry, but it is for GNSS receiver.
Has anyone had any similar experience, or any advice on how to remove those higher harmonics? We tried inserting ferrite beads with 1kOhm at 1.5 GHz, but they removed about 10 dB "only".
We appreciate any help!
