Design and implementation of an active array antenna with remote controllable radiation patterns for mobile communications

This paper presents an active array antenna for wideband code division multiple access (WCDMA) base station application with remote controllable radiation patterns. The proposed array consists of eight antenna elements and each element is integrated with a phase controllable radio frequency (RF) transceiver. The radiation pattern of the active array antenna or phased array antenna is consequently remote controllable. Meanwhile, due to the RF transceivers are directly connected to the antenna elements without any passive feed network, the feed line loss is greatly reduced and the efficiency is significantly improved. The local oscillator (LO) phase shifting technique based on a hybrid direct digital synthesizer (DDS) - phase-locked loop (PLL) approach is adopted to achieve high phase resolution. Consequently, a 360° phase shifting range with 0.35° tuning step can be achieved, which results in a 0.1° beam-steering resolution. To verify the proposed active array antenna, a prototype is developed and measured. The experiment data are in good agreement with the simulated results.