Controls the Rohde & Schwarz Phase Noise Analyzer via REST API. Use this skill when the user wants to measure phase noise, start PNA sweeps, check instrument health, or read frequency-domain data. Triggers include: "PNA", "phase noise", "sweep", "measure noise", "start measurement", "/measure/", "/health/". Also use when user mentions "Rohde & Schwarz", "spectrum", "PNR", or asks about "carrier suppression", "SSB phase noise". Do NOT use for general network requests unrelated to PNA instruments.
