True-Time-Delay Beamforming Receiver With RF Re-Sampling

Research output: Contribution to journalArticleScientificpeer-review

181 Downloads (Pure)


Analog domain true-time-delays (TTD) are desired in hybrid beamforming receivers with large relative bandwidths to mitigate the problem of beam squint. We propose a true-time-delay beamforming receiver architecture which enables squint-free wideband spatial filtering prior to the A/D conversion. The receiver implements true-time-delay with delayed re-sampling of the discrete-time output of a passive mixer. The receiver has the capability to extend the range of the beamforming delays from one to several carrier periods of the RF signal with pulse-skipped local oscillator (LO) signals, thereby enabling TTD beamforming with large antenna arrays. Further, a polyphase structure with parallel mixers is proposed to prevent spectral aliasing resulting from the lowered sample rate of the pulse-skipped LO signals. In addition, the maximum beamforming delay scales with the LO frequency, supporting large arrays also at low frequencies where the antenna separation set by the wavelength is large. We verify the proposed concepts with transistor-level simulation of the receiver implemented with a 28-nm CMOS process. The design achieves a squint-free beamforming for a 400 MHz RF bandwidth, and a maximum beamforming delay of three carrier time periods. The power consumption for a 3 GHz carrier frequency is 4 mW per antenna.
Original languageEnglish
Pages (from-to)4457-4469
Number of pages13
JournalIEEE Transactions on Circuits and Systems - I: Regular Papers
Issue number12
Early online date2020
Publication statusPublished - Dec 2020
MoE publication typeA1 Journal article-refereed


  • Analog beamforming
  • hybrid beamforming
  • true-time-delay
  • spatial filtering
  • RF sampling
  • re-sampling
  • beam squint
  • phased array
  • radio receiver
  • CMOS


Dive into the research topics of 'True-Time-Delay Beamforming Receiver With RF Re-Sampling'. Together they form a unique fingerprint.

Cite this