A Millimeter-Wave Front-End for FD/FDD Transceivers Featuring an Embedded PA and an N-Path Filter Based Circulator Receiver

Masoud Pashaeifar*, Leo C. N. de Vreede, Morteza S. Alavi

*Corresponding author for this work

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

1 Citation (Scopus)
10 Downloads (Pure)


This work presents an ultra-compact single-antenna FD/FDD transceivers front-end. It comprises a nonreciprocal circulator, RX, and an integrated power amplifier (PA). In the proposed circulator, we devise a ring quarter-wave transmission line topology with adjusted characteristic impedances to improve TX-to-antenna insertion loss and TX-to-RX isolation. Besides, an AND-gate switching-based N-path filter is proposed to realize the circulator's nonreciprocal gyrator while acting as a mixer-first RX. Owing to the ultra-compact N-path filter structure, the circulator occupies only 0.38mm 2 core area. Over a 27.1-to-31.1GHz band, the realized front-end offers >20dB TX-to-RX isolation while its measured TX-to-antenna insertion loss is 1.7~2.2dB. The RX path tolerates the PA's blocker signal, achieving 5dBm in-band and 13dBm out-of-band B 1dB. Moreover, the PA delivers 15.15dBm peak output power with 33% drain efficiency. Our front-end prototype occupies only 0.7mm 2 , including circulator, PA, quadrature hybrid coupler LO generators, and baseband circuits.
Original languageEnglish
Title of host publicationProceedings of the 2022 IEEE Radio Frequency Integrated Circuits Symposium (RFIC)
Place of PublicationDanvers
Number of pages4
ISBN (Electronic)978-1-6654-9611-7
ISBN (Print)978-1-6654-9612-4
Publication statusPublished - 2022
Event2022 IEEE Radio Frequency Integrated Circuits Symposium (RFIC) - Denver, United States
Duration: 19 Jun 202221 Jun 2022

Publication series

NameDigest of Papers - IEEE Radio Frequency Integrated Circuits Symposium
ISSN (Print)1529-2517


Conference2022 IEEE Radio Frequency Integrated Circuits Symposium (RFIC)
Country/TerritoryUnited States

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-care
Otherwise 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.


  • Blocker-tolerant receiver
  • CMOS circulator
  • FDD
  • full-duplex
  • mm-wave
  • N-path filter
  • power amplifiers

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