Antenna Offset Compensation in Quiet Zone EIRP Measurements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring equivalent isotropic radiated power (EIRP) and effective isotropic sensitivity (EIS) in wireless communication devices with offset antennas in test chambers face challenges due to unknown antenna array offsets, leading to significant path loss differences and inaccurate power-based metrics, especially in near-field measurements.
Innovation Solution
A method involving a black box testing approach where a far-field probe antenna establishes an OTA connection with the device under test (DUT), locks the antenna beam in the desired direction, and performs near-field measurements using a near-field probe antenna, compensating for antenna offsets to ensure accurate EIRP and EIS measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If far-field measurements are performed, then measurement distance is large enough to satisfy far-field conditions, but measurement chamber size and path loss increase significantly
Solution Approach 1:
The patent changes the measurement parameter from far-field to near-field, allowing measurements to be performed at much shorter distances while still obtaining accurate EIRP and EIS values through appropriate signal processing and calibration techniques
2Adaptability or versatility
If AUT is offset from quiet zone center, then black box testing is enabled, but measurement accuracy deteriorates due to unknown path loss
Solution Approach 1:
The patent replaces the need for precise mechanical positioning and alignment with a signal processing approach, using reference measurements and calibration to compensate for the unknown offset between the AUT and quiet zone center
Solution Approach 2:
The patent introduces reference signals and calibration procedures as intermediaries to establish the relationship between the AUT position and the measured power, enabling accurate measurements without direct knowledge of the offset distance
3Length of stationary object
If near-field measurements are performed with offset AUT, then measurement distance is reduced, but measurement complexity increases due to offset compensation requirements
Solution Approach 1:
The patent performs preliminary calibration measurements and establishes reference data before conducting the actual EIRP/EIS measurements, which simplifies the main measurement process by pre-characterizing the system response
Data Source
AI summary
A system and method are provided to determine equivalent isotropic radiated power (EIRP), effective isotropic sensitivity (EIS) and/or signal quality of a DUT in a test chamber, where the DUT has an AUT that has beam-forming capability and is offset from a center of a quiet zone of the test chamber. The method includes establishing a connection with the DUT using a far-field probe antenna in a far-field of the test chamber relative to the AUT so that the AUT forms a beam in a beam peak direction towards the far-field probe antenna; locking the beam of the AUT in the beam peak direction to prevent subsequent beam forming; and performing a near-field measurement of the EIRP, the EIS and/or the signal quality of the AUT with the beam locked in the beam peak direction using a near-field probe antenna in a near-field of the test chamber.