[New Feature - 5.11.0] Antenna gain profile

Products ePMP
1

Applicable versions: 5.11.0 and above
Applicable platforms: AX radios with integrated antenna

Traditionally, Cambium radios used a fixed antenna gain value (e.g., 25 dBi) across the entire operating frequency range. While simple, this approach does not reflect how real antennas behave – their gain varies with frequency.

The Antenna Gain Profiles feature introduces a more accurate way to handle antenna performance by using up to 8 data points per antenna that map gain vs. frequency. This allows the system to calculate the actual gain at a specific operating frequency and adjust transmit power accordingly.

ePMP 4500 8x8 5GHz Integrated Sector Antenna 17dB Gain

image
image762×545 159 KB

Imprortance

  • More realistic modeling: Antenna gain is no longer treated as a flat number but as a curve derived from real antenna measurements.

  • Better regulatory compliance: Transmit power (EIRP) calculations are based on true antenna performance, ensuring limits are respected.

  • Optimized performance: Where the antenna is less efficient at a frequency, the radio can safely increase transmit power to compensate.

Feature operation

  1. Profiles per antenna
    Each Cambium antenna has a profile derived from its lab-measured gain chart. The profile contains up to 8 points that map gain across frequencies.

  2. Gain calculation
    The system uses linear interpolation between the points. Precision is 1 dB for now, which simplifies implementation without sacrificing accuracy.

  3. Automatic adjustments

  • At driver start or when frequency changes, the gain is recalculated.

  • If the actual antenna gain is lower than the maximum expected, the radio can boost TX power by the delta.

  • This happens in the background – no GUI controls are required.

  1. Supported integrations
    The feature has been integrated with key subsystems like ACS, DCS, and DFS. It also works with AP and SM modes.

Improvements

  • Radios will automatically apply the antenna profile in the background.

  • No additional configuration is required.

  • Users benefit from optimized TX power and more accurate EIRP validation without needing to manage profiles manually.

2 Likes
2

Is there a reason this could not apply to connectorized radios like the 4600AP? There is no 6ghz AP with integrated antennas and I am sure the Cambium 4x4 6ghz sector does not have even gain across the whole 6ghz band. Would be nice to be able to have this feature for tested and supported antennas, or at least for any Cambium branded antennas.

2 Likes
3

Hi @terintamel,

it may be implemented in the next stage of the feature development.
Thank you!