Oregon State University

Can’t find an event? We’re busy migrating to a new event calendar. Try looking new calendar



Event Details

PhD Final Examination – Abhishek Agrawal

Monday, June 12, 2017 9:00 AM - 11:00 AM

Scalable array transceivers with wide frequency tuning range for next generation radios
Scalable array transceivers with wide frequency tuning range are attractive for next-generation radios. Key challenges for such radios include generation of LO signals with wide frequency tuning range, scalable synchronization between multiple array unit cells and tolerance to in-band and out-of-band interferers. This thesis presents approaches to address these challenges in commercial CMOS technologies.

The first part focuses on a series resonant mode-switching VCO architecture that achieves both state-of-art area and power efficiency with an octave frequency tuning range from 6.4 GHz-14 GHz in 65nm CMOS.

In the second part a scalable, single-wire coupled-PLL architecture for RF/mm-wave arrays is presented. The proposed architecture preserves the simplicity of a daisy-chained LO distribution, compensates for phase offset due to interconnect, and provides phase noise improvement commensurate to the number of coupled PLLs. Measurements on a 28 GHz CMOS prototype demonstrate the feasibility of this scheme.

The third part of this thesis presents filtering techniques for in-band blocker suppression. A spatial/spectral notch filter design for MIMO/digital beam forming arrays is proposed to relax the ADC dynamic range requirement. Orthogonal properties of Walsh functions incorporated into passive N-path approach enable reconfigurable notches at multiple frequencies and angles of incidence.

Finally, A code-domain N-path RX is proposed based on pseudo random (PN) code modulated LO pulses for simultaneous transmission and reception (STAR) applications. A combination of Walsh-Function and PN sequence is proposed to create code-domain matched filter at the RF frontend which reflects unknown in-band blockers and rejects known in-band TX self-interference (SI) by using orthogonal codes at receiver input thereby maximizing the SNR of the received signals. Additionally, a concurrent reception of two code-modulated signals signal is demonstrated.

Major Advisor: Arun Natarajan
Committee: Andreas Weisshaar
Committee: Un-Ku Moon
Committee: Karti Mayaram
GCR: Zhenxing Feng

Kelley Engineering Center (campus map)
Calvin Hughes
1 541 737 3168
Calvin.Hughes at oregonstate.edu
Sch Elect Engr/Comp Sci
This event appears on the following calendars: