Thermal-Aware Synthesis of 5G Base Station Antenna Arrays: An Overview and a Sparsity-Based Approach

Multiple Beam Synthesis of Passively Cooled 5G Planar Arrays Using Convex Optimization

“…For such systems, intuitively, it can be inferred that more elements (chips) should be placed at the edges of the aperture since otherwise, the heat gets trapped in the middle of the array. However, as explained in [9], such traditional arrays are not preferred in 5G since they are incompact and they need a large number of RF boards with additional cabling for signal routing. What industry prefers today for 5G is a single, multi-layer RF board antenna that is low-cost and low-profile.…”

“…In 5G, as suggested in [9], the commercially available, lowcost and reliable passive CPU coolers with large heat removal capabilities can directly be used for cooling by attaching the transceiver chips to the baseplate of the cooler. An example of a standard CPU cooler [11] is given in Fig.…”

Active Multiport Subarrays for 5G Communications

“…(D-ii) The number of simultaneously served far-away users (that need the gain from all the subarrays) is limited by the number of BM ports. However, in [32], it was shown that the number of users cannot be very large (K, P < 8 for the current chip technologies) due to the thermal management problems which is preferred to be handled passively via natural convection [33].…”

“…(D-iii) Due to large spacing between the subarrays, grating lobes (GLs) will occur in the field of view which may create very large interference if not suppressed. Besides, ZF algorithm does not work for two users located near each other's grating lobes [33]. However, placing the subarrays smartly can help suppress the GLs and allow us to use CB or ZF [33] with sufficiently low interference.…”

“…Besides, ZF algorithm does not work for two users located near each other's grating lobes [33]. However, placing the subarrays smartly can help suppress the GLs and allow us to use CB or ZF [33] with sufficiently low interference. An alternative way to dissolve the GLs is to use overlapped subarrays [34] (with a more complex analog beamformer) instead of the contiguous ones, which is not discussed in this paper.…”