Лабораторная 6.3 — AD9363 settings and iio_attr¶
Lab 6.3 — AD9363 Settings and iio_attr Quick Reference¶
Goal¶
Create a reproducible checklist for configuring an AD9363-based RF frontend and documenting the exact settings used during an SDR experiment.
The lab answers the practical question:
Which AD9363 parameters must be recorded and controlled so that an RF measurement can be repeated later?
Engineering context¶
In a real SDR experiment, the observed signal depends not only on DSP code. It also depends on RF frontend settings:
- LO frequency;
- RF bandwidth;
- sampling frequency;
- gain mode;
- hardware gain;
- enabled channels;
- analog filter state;
- external attenuation;
- AGC/manual gain behaviour.
If these settings are missing, the IQ recording is not reproducible.
Typical IIO device naming¶
Exact names depend on the board image and Linux/IIO configuration. Common names are:
ad9361-phy
cf-ad9361-lpc
cf-ad9361-dds-core-lpc
Some boards expose an AD9363 transceiver through an ad9361-phy compatible IIO device name. Always inspect the available devices on your system.
Discovery commands¶
List IIO devices:
iio_info -s
Inspect device attributes:
iio_attr -d ad9361-phy
Inspect channel attributes:
iio_attr -c ad9361-phy
Inspect one channel:
iio_attr -c ad9361-phy voltage0
Common RX parameters¶
| Purpose | Example command | Notes |
|---|---|---|
| RX LO frequency | iio_attr -c ad9361-phy altvoltage0 frequency 915000000 |
channel name may differ |
| RX RF bandwidth | iio_attr -c ad9361-phy voltage0 rf_bandwidth 2000000 |
Hz |
| RX sampling frequency | iio_attr -c ad9361-phy voltage0 sampling_frequency 2400000 |
Hz |
| RX gain control mode | iio_attr -c ad9361-phy voltage0 gain_control_mode manual |
prefer manual for measurements |
| RX hardware gain | iio_attr -c ad9361-phy voltage0 hardwaregain 10 |
dB, range depends on hardware |
Common TX parameters¶
| Purpose | Example command | Notes |
|---|---|---|
| TX LO frequency | iio_attr -c ad9361-phy altvoltage1 frequency 915000000 |
channel name may differ |
| TX RF bandwidth | iio_attr -c ad9361-phy voltage0 rf_bandwidth 2000000 |
output channel naming may differ |
| TX sampling frequency | iio_attr -c ad9361-phy voltage0 sampling_frequency 2400000 |
check TX device/channel |
| TX attenuation / gain | iio_attr -c ad9361-phy voltage0 hardwaregain -20 |
sign/range is board dependent |
Board-specific names
The exact channel names for RX/TX LO and voltage channels may differ. Treat the commands above as a checklist pattern, not as a guaranteed universal command set.
Minimal configuration checklist¶
Before capture or transmission, record:
| Field | Value |
|---|---|
| Board name | |
| Linux image / firmware | |
| IIO context URI | |
| PHY device name | |
| RX LO frequency | |
| TX LO frequency | |
| RX sample rate | |
| TX sample rate | |
| RX RF bandwidth | |
| TX RF bandwidth | |
| RX gain mode | |
| RX hardware gain | |
| TX attenuation/gain | |
| External attenuation | |
| Signal type | |
| Expected baseband offset |
Safe configuration procedure¶
- Connect attenuator before enabling TX.
- Use low TX level / high TX attenuation.
- Use manual RX gain for repeatability.
- Set LO frequencies.
- Set sample rates.
- Set RF bandwidths.
- Generate a low-level single tone.
- Observe spectrum for overload.
- Save settings and IQ metadata.
- Only then proceed to modulation experiments.
Example session log¶
# Discover devices
iio_info -s
# Inspect the PHY
iio_attr -d ad9361-phy
# Set center frequency examples
iio_attr -c ad9361-phy altvoltage0 frequency 915000000
iio_attr -c ad9361-phy altvoltage1 frequency 915000000
# Set bandwidth and sample rate examples
iio_attr -c ad9361-phy voltage0 rf_bandwidth 2000000
iio_attr -c ad9361-phy voltage0 sampling_frequency 2400000
# Set manual gain example
iio_attr -c ad9361-phy voltage0 gain_control_mode manual
iio_attr -c ad9361-phy voltage0 hardwaregain 10
What to include in the report¶
- exact commands used;
- command outputs or screenshots;
- frequency plan from Lab 6.1;
- gain plan from Lab 6.2;
- IQ metadata file;
- spectrum screenshot or generated FFT;
- overload check conclusion.
Engineering conclusion template¶
The AD9363 frontend was configured with RX LO = ____ MHz, TX LO = ____ MHz,
RX sample rate = ____ MS/s, RF bandwidth = ____ MHz and RX gain mode = ____.
The settings were recorded through iio_attr and linked to the IQ metadata file.
The observed spectrum confirms / does not confirm the expected RF configuration because ______.