RF Test

  • RF
  • RVR
  • Wi-Fi
  • iperf
  • RF calibration
  • NVS
  • PHY
  • Deep-sleep
  • I/Q
  • partial calibration
  • full calibration
  • no calibration

What is the standard process for Wi-Fi module RVR (Rate vs Range) testing?

RVR (Rate vs Range) testing evaluates Wi-Fi throughput at different signal strengths (RSSI). To make results comparable, use a consistent test method:

  • Use a fixed AP and lock parameters such as channel and bandwidth.
  • Keep device settings consistent, including TX power, power-save mode, and firmware version.
  • Run a baseline throughput test under strong-signal, short-distance conditions.
  • Gradually reduce RSSI by increasing distance or adding attenuation, and record performance at each RSSI point.
  • In weak-signal conditions, for example below -80 dBm, observe throughput changes and whether disconnection occurs.

Use the same iperf version across tests and measure both uplink and downlink throughput.

Additional recommendations:

  • Test environment: use a fixed AP, disable automatic channel selection and load balancing, and use an RF chamber or attenuator when reproducibility is required.
  • Device configuration: keep AP channel, bandwidth, and encryption fixed; keep STA TX Power fixed, disable power saving, and use the same firmware version.
  • Test method: establish the near-range baseline first, then repeat tests at multiple RSSI points and average the results.
  • Result analysis: plot RSSI vs throughput, and watch the throughput drop trend, packet loss, and disconnection point. The disconnection point is often around -85 ~ -90 dBm, but it varies by environment.

What does automatic RF calibration on a module include, and which calibration modes are supported?

Calibration coverage:

To compensate for performance variations in the RF transceiver, the chip's automatic RF calibration mainly includes carrier leakage cancellation, I/Q phase matching, baseband nonlinearity suppression, RF nonlinearity suppression, and antenna matching.

Calibration modes:

  1. Partial calibration (default): During normal startup, the module performs RF calibration using the full calibration data stored in NVS, allowing a faster startup.
  2. Full calibration: Full RF calibration is triggered on the module's first startup, or when NVS is missing or erased, the hardware MAC address changes, the PHY library version changes, or the RF calibration data in NVS is corrupted. Compared with partial calibration, full calibration takes approximately 100 ms longer.
  3. No calibration: Automatic calibration is not performed when the module wakes from Deep-sleep.