Abstract: In one embodiment, an LSAS base station has a tree architecture including a central controller at the tree root, one or more intermediate levels of hubs forming tree branches, and an antenna module for each service antenna at a tree leaf. To calibrate an overall ratio characterizing differences between downlink and uplink channels between the central controller and each antenna module, neighbor-calibration procedures are calibrate neighbor ratios between parent nodes and their child nodes. Appropriate neighbor ratios are multiplied to generate overall ratios. To reduce time required to perform the neighbor-calibration procedures, odd and even phases are performed. In the odd phase, neighbor ratios are generated between parents in all odd levels and their children in even levels, and analogously for the even phase for even-level parents and odd-level children. Within each phase, independent parent-child pairs can be calibrated simultaneously.

Abstract: In one embodiment, an LSAS base station has a tree architecture including a central controller at the tree root, one or more intermediate levels of hubs forming tree branches, and an antenna module for each service antenna at a tree leaf. To calibrate an overall ratio characterizing differences between downlink and uplink channels between the central controller and each antenna module, neighbor-calibration procedures are calibrate neighbor ratios between parent nodes and their child nodes. Appropriate neighbor ratios are multiplied to generate overall ratios. To reduce time required to perform the neighbor-calibration procedures, odd and even phases are performed. In the odd phase, neighbor ratios are generated between parents in all odd levels and their children in even levels, and analogously for the even phase for even-level parents and odd-level children. Within each phase, independent parent-child pairs can be calibrated simultaneously.

Abstract: In a symmetric crossover structure of two lines formed of a lower conductor layer and a higher conductor layer above a substrate, each of the two lines is branched to two routes at where they are crossed over to each other. The first route of the first line uses the higher layer to cross the first route of the second line and the lower layer to cross over the second route of the second line. The second route of the first line uses the lower layer to cross over the first route of the second line and the higher layer to cross over the second route of the second line. The two lines therefore have symmetric coupling effects to the substrate.