Analysis of hybrid-passive-active phased array configurations based on an SNR approximation

In this work, the impact of different system configurations on the SNR performance of hybrid-passive-active phased arrays is studied. The separation of the functional core components of active arrays into active and passive parts provides the possibility to reduce power consumption, size and cost, which is of interest especially in mobile applications. Power consuming and expensive active components, such as LNAs, can be shared by multiple antenna elements, whereas passive components, e.g. passive phase shifters, are assigned to each antenna element for beam steering. To estimate the performance of such systems, a noise model is derived for a planar M × N, corporate fed array in tile construction. With this model, it is possible to determine an optimum array configuration in terms of array size and LNA distribution for a given SNR design goal and a given set of limiting factors. Finally, the applicability of this method is demonstrated for a 60 GHz scenario.