Distributed Active Power Combiners and Splitters for Multi-Antenna UWB Transceivers

This paper presents the design of CMOS active power combiners and splitters with wideband variable gain and delay using distributed architectures. The proposed circuits are the key components for use in multi-antenna (MA) ultra-wideband (UWB) communication systems with beamforming. The proposed distributed active power combiner and splitter operate across 1-10.6GHz bandwidth. Power gain of each path of the combiner and splitter is independently controllable from -15dB to 6dB and from -16dB to 9.5dB, respectively. The wideband variable delay of each path of the power combiner is 32 to 42 ps, and for each path of the power splitter is 43 to 53 ps across the UWB frequency range. Both power combiner and splitter have been fabricated in a 0.13mum CMOS process. Supplied from a 1.8V power-supply, the 2-stage distributed active power combiner consumes 8.5mA, and the 3-stage distributed active power splitter draws 11.4mA