A 28GHz MIMO Receiver with Spatial Filtering and Frequency-Division Multiplexing
The evolution of mm-wave phased array receivers (RX) from multiple-input single-output (MISO) to multiple-input multiple-output (MIMO) RX promises multi-beamforming and improved capacity. While digital beamforming (DBF) provides the highest flexibility, digitization in the beam space instead of element space enables ADC power/dynamic range (DR) scalability as the number of beams (≤4) scale. Additionally, spatial filtering prior to the ADC relaxes the DR requirements for the ADC. Mm-Wave MIMO arrays must also address the challenge of increased IO routing while supporting dense fill-factors with λ/2 antenna spacing.
In this work we present a MIMO beam-space RX array architecture with simultaneous spatial filtering and single wire frequency-domain multiplexing (FDM). The reconfigurable weighted multi-phase mixing based beam-space RX scheme achieves both (a) multi-beam formation/spatial filtering and (b) FDM of multiple beam-space outputs. Additionally, it preserves full MIMO field-of-view while ensuring a single IF interface to ensure reduced I/O.
Major Advisor: Arun S Natarajan
Committee: Andreas Weisshaar
Committee: Matthew Johnston
Committee: Tejasvi Anand
GCR: Karl Haapala
Friday, October 30 at 2:00pm to 4:00pmVirtual Event