Abstract
Hybrid digital and analog beamforming is an emerging technique for high-data-rate communication at millimeter-wave (mm-wave) frequencies. Experimental evaluation of such techniques is challenging, time-consuming, and costly. This article presents a hardware-oriented modeling method for predicting the performance of an mm-wave hybrid beamforming transmitter. The proposed method considers the effect of active circuit nonlinearity as well as the coupling and mismatch in the antenna array. It also provides a comprehensive prediction of radiation patterns and far-field signal distortions. Furthermore, it predicts the antenna input active impedance, considering the effect of active circuit load-dependent characteristics. The method is experimentally verified by a 29-GHz beamforming subarray module comprising an analog beamforming integrated circuit (IC) and a 2 2 subarray microstrip patch antenna. The measurement results present good agreement with the predicted ones for a wide range of beam-steering angles. As a use case of the model, far-field nonlinear distortions for different antenna array configurations are studied. The demonstration shows that the variation of nonlinear distortion versus steering angle depends significantly on the array configuration and beam direction. Moreover, the results illustrate the importance of considering the joint operation of beamforming ICs, antenna array, and linearization in the design of mm-wave beamforming transmitters.
Highlights
T HE large available bandwidth in millimeter-wave bands can be explored to meet the demand for high-data-rate communication [1]–[3]
The subarray module consists of a two-by-two planar microstrip patch antenna array, which is connected to an evaluation board (EVB) of a quad-channel analog beamforming integrated circuit (IC)
We combined a load—pull-based nonlinear model of an analog beamforming unit with antenna characteristics to develop an iterative algorithm for prediction of hybrid beamforming transmitter performance at mm-wave frequencies
Summary
T HE large available bandwidth in millimeter-wave (mm-wave) bands can be explored to meet the demand for high-data-rate communication [1]–[3]. Only a limited number of studies have incorporated PA models into active antenna array simulations for evaluating transmitter performance [14], [18]–[22]. Considering the importance of evaluating nonlinear signal distortion in active antenna arrays, a dual-input behavioral model with memory has been developed [19] and later used in [21] and [22] to address transmitter signal nonlinearities This prediction method has not been validated beyond 3 GHz. the radiation pattern has not been studied in conjunction with the signal distortion. In the second part of this article, the proposed analysis method is exploited in a simulation-based study to predict nonlinear distortion in various large-scale beamforming transmitter configurations.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Microwave Theory and Techniques
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
