Abstract
Digital beamforming receivers (RXs) support MIMO operation and offer great flexibility and accuracy in multi-beam formation and calibration. However, compared with analog phased-array and hybrid systems, due to the absence of any rejection for spatial in-band blockers, the RX/ADC dynamic range and linearity should be high enough to prevent array saturation. Therefore, the use of self-steering spatial notch filters (SNFs) is necessary to aid the digital beamformers and reduce RX/ADC power consumption while strong blockers exist. To address that, the sub-6GHz RXs in [1], [2] synthesize a baseband spatial notch impedance and translate it to RF by passive mixers. However, this technique cannot be directly applied at mm-wave frequencies as the impedance translational performance of the passive mixers degrades significantly. Hence, the mm-wave beamformer in [3] realizes a cascadable SNF at an intermediate frequency (IF). However, the front-end mm-wave components like mixers and phase shifters have to tolerate strong blockers, thus degrading RX linearity. Besides, it uses multiple IF buffers and VGAs for signal scaling and combining, which could be power-hungry if a similar method is adopted to realize a mm-wave SNF. To improve on those limitations, we propose a scalable SNF structure, which (1) suppresses the strongest in-band blocker at mm-wave frequencies, (2) supports N-input-N-output MIMOs, and (3) requires no active blocks except the phase shifters. A two-step autonomous notch-steering technique is also developed to adjust the SNF notch direction power-efficiently and accurately.
Original language | English |
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Title of host publication | 2022 IEEE International Solid- State Circuits Conference (ISSCC) |
Subtitle of host publication | Digest of technical papers |
Editors | Laura C. Fujino |
Place of Publication | Danvers |
Publisher | IEEE |
Pages | 82-84 |
Number of pages | 3 |
ISBN (Electronic) | 978-1-6654-2800-2 |
ISBN (Print) | 978-1-6654-2801-9 |
DOIs | |
Publication status | Published - 2022 |
Event | 2022 IEEE International Solid- State Circuits Conference (ISSCC) - Online at San Francisco, United States Duration: 20 Feb 2022 → 26 Feb 2022 |
Publication series
Name | Digest of Technical Papers - IEEE International Solid-State Circuits Conference |
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Volume | 2022-February |
ISSN (Print) | 0193-6530 |
Conference
Conference | 2022 IEEE International Solid- State Circuits Conference (ISSCC) |
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Abbreviated title | ISSCC 2022 |
Country/Territory | United States |
City | Online at San Francisco |
Period | 20/02/22 → 26/02/22 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.