Hybrid adaptive antenna array

Abstract

Disclosed is a hybrid antenna array (100) comprising a plurality of digital branches (145), each digital branch including an analogue beamforming sub-array (e.g. 110-1), each sub- array having a plurality of antenna elements (120), a phase shifter (130) adapted to apply a phase shift to the signal from each antenna element, and a combiner (e.g. 135-1) adapted to combine the phase-shifted signals. Each digital branch also includes a signal chain (e.g.140-1) adapted to convert the output of the sub-array to baseband. The hybrid antenna array also comprises a digital processing module (150), including: an angle of arrival estimation sub-module (155) adapted to estimate an angle of arrival of a signal at the antenna elements; a phase control sub-module (170) adapted to control the phase shift applied by each phase shifter depending on the estimated angle of arrival; and a digital beamformer (165) adapted to combine the baseband signals from the digital branches using a weight vector to form an output signal (180).

Description

technical field [0001] The present invention relates generally to antenna design, and more particularly to architecture and methods for adaptive antenna arrays. Background technique [0002] Adaptive antennas are important subsystems for long-range, mobile and ad hoc wireless communication and sensing networks. The most powerful adaptive antenna architecture is a digital beamforming array, where each antenna element has an associated signal chain to convert the received signal from RF (radio frequency) to baseband, and the digital beamformer uses adaptive filtering techniques to baseband The signal is processed. Digital beamforming antenna arrays have the ability to simultaneously generate multiple antenna patterns, perform high-precision beamforming such as nulling, and generate output signals with maximum signal-to-noise-interference ratio (SNIR). Another advantage of the digital beamforming array architecture is that the online calibration of the different branches can ...

AI Technical Summary

Problems solved by technology

However, analog beamformers have specific disadvantages

First, calibration of large analog arrays is labor-intensive, and in-line calibration is particularly difficult

second, special equipment must be used to implement beam tracking, thus increasing complexity and cost

Third, since the phase-shifted IF or RF signals are combined before conversion to baseband, there is no access to the baseband signals of the individual analog branches, limiting the ability to form selective beam patterns

These problems are especially acute for large analog arrays, where component defects and aging can severely degrade antenna performance

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