Hi,
I'm making up a PCB for a software defined radio and I am wondering about the ramifications of placing a coax connector between the LNA output and mixer input. I want to be able test the LNA/mixer in isolation in circuit by lifting coupling capacitors/0R resistors to ensure they match the measurements I made before on isolated PCBs.
Assuming that I place the footprint for an SMA connector with the signal pin in line with the LNA and mixer to trace to avoid any extra trace length or stubs, will the presence of the footprint have any negative effects on the signal integrity? And what difference would there be between the effect of populating and not populating the connector?
If it's useful: I only really care about 1.575GHz (GPS), the LNA is 50 ohm output and the mixer IC input is 75 ohm so matching is used and the PCB will be standard FR4.
Thanks in advance for any help you can provide,
Tom