Our customer is using ADF4355 and ADF5355 by same circuit and layout. But, the output level of ADF4355 is lower than ADF5355. The output level is around -5dBm at 3400MHz and -30dBm at 6000MHz. The register setting of ADF4355 is also same as ADF5355. Do you have any idea about the cause of the power degradation?
I attached the circuit around output pins of ADF4355. THe output lines are connected to transformer (TCM1-83X+) by Mini-Circuit.
I worry about a connection of 15 pin. It is GND pin for ADF5355, but it is RFoutB- for ADF4355. Do the out ut level of RFoutA+/A- degrade when we connect 15pin of ADF4355 to GND?