A common question to our support team is "how do I verify my antenna is really X dBi gain?"
Gain inflation is rampant online (see related article), and because the gain of an antenna varies based on frequency, advertised gain may be true but misleading. For example, a multispectrum 600-2700 MHz antenna may have 8 dBi at 2.4 Ghz but only 4 dBi at 900 Mhz. So if the antenna is advertised as 8 dBi, it's not wrong, but it may not be the right antenna for you if shopping for a lower frequency (see related article discussing multi-spectrum vs. tuned antennas).
Antenna gain measurement- three ways to ensure gain accuracy
- Buy from a reputable antenna manufacturer or designer like Rokland. Big box stores and general retail distributors rely on scant information given to them from a manufacturer about a product. If you are buying from a general retailer and not an antenna manufacturer, designer, or company that specializes in antenna technology, you are more likely to encounter inaccurate or misleading information, such as outline above about multi spectrum antennas and gains
- Request VSWR reports and beamwidth charts from the retailer. While this information will not tell you exactly what the gain is at a specific frequency, it can help you understand if you are using a multi spectrum antenna or one tuned to a specific frequency range.
- Lab test. This is costly and will vastly exceed the price of a single antenna. Single antenna customers will generally need to rely on documentation provided by the antenna retailer. If you are looking for a volume purchase for mass deployment however, and performance is critical, securing a test laboratory that specializes in antenna testing can help ensure you are getting what is advertised and needed.
If you are interested in making a volume purchase, please contact us. We can provide documentation or help arrange additional lab testing.