Other your company China support, they suggest me to tune AT1 and AT2 matching value in passive mode and do not supply 3VDC. And Network Analyzer RF in connect on the M20057 module C2 component pad. Can you advise which method is more accurate for matching value.
At the same time, I also try to tune matching value by passive mode. But I cannot match to 50ohm at module C2 pad. I found AT1 and AT2 value will not move toward smith chart standard circle line. I try to place different capacitor/inductor/0R value in AT1 and AT2 pads. The smith chart result point also place on the upper of half circle. The return loss value also cannot get under -10dB in 1559MHz-1609MHz. The optimistic return loss result is just -4.7dB (AT1=1.3nH and AT2=0.4nH).
Thanks in advance.
Tim Lin email:
My tuning result: