Table of Contents

OTA vs. conducted testing

Wireless test methods include conducted and over-the-air (OTA) testing. Conducted tests are performed without antennas via 50 coaxial cabling connected to the DUT antenna ports. An OTA test setup has to couple a 3-dimensional electromagnetic energy field into the test instrumentation, which is considerably more challenging to do in a controlled and repeatable manner.

ota vs conducted

Ideal field pattern of a dipole antenna

Figure 5: Standing waves create signal fluctuation vs. time

An example field pattern of a phone against a human head with some of the energy absorbed by the head

OTA testing is necessary to test antenna contribution to the performance of the device or to measure 3D radiation patterns.

OTA testing is also desirable in production since modern devices often have integrated antennas that are difficult to remove for testing.

Common radio performance metrics, including TX EVM (error vector magnitude), RX sensitivity, blocker testing, channel emulation and other tests can be performed either conducted or OTA.

OTA testing takes into account antenna field pattern and can be performed over a spherical space around the device or at a variety of DUT orientations.

OTA testing is becoming increasingly important with the emergence of smart antenna technologies such as MIMO and beamforming.

With its superior isolation, far field conditions and field stability, octoBox supports both OTA and conducted testing.