Simulation of a Novel Phase Retrieval Technique for Multi-axis Robotic Arm Based Near-Field Antenna Measurements

The simulation of a novel robot-arm based near-field/far-field (NF/FF) antenna measurement system enabling the reconstruction of measured AUT phase without the need for a phase reference cable is described. The mathematical approach follows the principle used within GPS position and time recovery. This work addresses the need for industrial robot arm-based NF/FF antenna measurements at both microwave and importantly millimetrewave frequencies where the transmitting probe RF phase reference cannot be guaranteed to be provided with the necessary stability by cable management or rotary joints. To assess the viability a computer simulation of the measurement system is constructed, and its performance analysed in terms of the accuracy of reconstruction of the AUT phase and true NF probe location, as well as the NF/FF radiation pattern accuracy in terms of Equivalent Multipath Level (EMPL). We demonstrate that a microwave system can offer EMPL below -60dB and that a millimetrewave system operating from 40GHz to 100GHz can offer EMPL below -50dB.