Influence of cable routing for indoor multi-system omnidirectional antenna horizontal pattern ripple measurement

Horizontal pattern ripple or roundness is an important figure of merit for indoor omnidirectional antennas. The roundness measurement uncertainty due to test cable routing is investigated in this paper. Simulations on GSM, TD-SCDMA, WCDMA, wireless local area network (WLAN) and long term evolution (LTE) system have been done for eight kinds of testing cable routing influence for the indoor antenna roundness of horizontal pattern. By analyzing typical cases of ripple measurement, it is found that some kinds of testing cable routing could influence the roundness of antenna horizontal pattern significantly. Simulation and experimental results demonstrate that straight or spiral ripple has little influence for the antenna roundness measurement. This work will help standardize the measurement setup for the omnidirectional antennas.