Hi,
It depends on what circuit you are debugging. For example, if u find the sensitivity of a receiver is not enough. You should consider the RX path. LNA, downconverter and demodulation circuits are included in receiving path. In order to ensure to get enough sensitivity, you should ensure all parts in RX path are work fine. First, you should check the LNA. Critical parameters in LNA are noise figure and gain. If the NF is low enough and gain is high enough, then the LNA is okay. Second, you should check the mixer. If the IP3 and gain (if the mixer is active mixer) are high enough. Then the mixer is okay. Third, check the demodulation circuit, check whether it can demodualte the waveform correctly or not.
Finally, you should check the matching in interstage. Ensure each stage are well matched.
Debugging a RF circuit should be done step by step... I hope it can help u
yakult