Low Loss Integrated N-Path-Filter-Based Circulator

Low Loss Integrated N-Path-Filter-Based Circulator
December, 24, 2017
in Room 1061 Electrical Eng. Building Technion City

Graduate Seminar

Speaker:    Roy Weiss

Affiliation:  Dept. of Electrical Engineering , Technion


Low Loss Integrated N-Path-Filter-Based Circulator
Full-duplex (FD) is a system architecture where the transmitter and the receiver operate at the same time and at the same frequency. Using a passive shared-antenna interface in a high-end FD system dictates the use of a circulator. Conventional circulators rely on magnetic materials and cannot be integrated on silicon. However, previous work have showed that an N-Path-Filter-Based circulator can be integrated in a standard CMOS process, which suits perfectly for mass production applications such as mobile communication.
In this seminar, the integrated N-Path-Filter-Based circulator will be thoroughly analyzed. Simplified linear time invariant (LTI) circuit models will be introduced in order to perform the analysis. These models will then be verified by comparison to the complex linear periodic time varying (LPTV) model of the circulator. Exploiting the insight acquired from the simplified models, a new and improved topology for the integrated circulator will be proposed. The simulated sum of Tx-to-Ant insertion losses and NF of the proposed circulator are less than 1dB at 100MHz and less than 2dB at 2GHz. These results are significantly better than the previously reported state-of-the-art integrated circulator. Finally, a test chip, sent for fabrication in TSMC 65nm process, and additional design considerations will also be presented.