Carrier aggregation receiver employing direct recentred offset receivers

Carrier aggregation supports an increased total bandwidth, data rate and utilization of available fragmented spectrum, where the latter is a core component of next generation Wi-Fi and Cellular networks, including 5G. Wireless communications receivers with intra-band non-contiguous CA, employing conventional complex mixers and base-band circuitry, are desirable, however risks of VCO injection pulling and LO coupling may hinder adoption of simplistic parallel receive channels. Furthermore, in-band strong blockers are expected in such environment and the CA receiver should be designed to tolerate such signals. This paper introduces a scalable CA receiver architecture, enabling co-existence of multiple LO signals and respective down conversion of recentered, offset signals of flexibly spaced component carriers. The architecture presented here supports an aggregation of intra-band, inter-band and inter-standard component channels, employing conventional base-band signals, where the performance per receive channel is compatible with Legacy (single channel) performance. A flexible CA receiver demonstrating this architecture with 3 component channels is implemented in 65nm CMOS LP process and occupies a die area of 1mm², operating at 5.2-5.8GHz.