Correcting Antenna Pattern in Offset Measurements Based on Equivalent Dipole Moments

Ahstract-A correct antenna pattern is required to ensure the accurate evaluation of antenna design, total radiated power (TRP), total isotropic sensitivity (TIS), receiver sensitivity and etc. However, in some cases the antenna pattern is obtained off-center, which degrades its accuracy. In this paper, an algorithm based on the equivalent dipole moment method is proposed to correct the offset antenna pattern. Detailed derivations and workflow are presented. Besides, the dipole moment extraction is automated by optimization algorithms. A numerical test case is used to benchmark the proposed antenna pattern correction algorithm.

I. Introduction

With the rapid development of the consumer electronic devices, more and more antennas are integrated into a device, such as a cellphone, a pad, a laptop, a TV set and etc. Antennas' performance plays a significant role in determining the signal quality, data rate and thus the user experience. The antenna performance is essentially characterized by the antenna pattern. An antenna pattern directly reflects several critical antenna characteristics including gain, main lobe, side lobes, beamwidth and etc. An antenna pattern is also utilized to calculate the total radiated power (TRP) [1] and total isotropic sensitivity (TIS) [2]. These characteristics in turn facilitate the system design and debugging. Furthermore, antenna patterns are further exploited to benefit throughput tests, receiver sensitivity tests and desense diagnosis [3], [4]. It is becoming increasingly important to obtain an accurate antenna pattern. Fig. 1.

OTA tests with AUT off-center.