True-Time-Delay Beamforming Receiver With RF Re-Sampling
Autor: | Jussi Ryynanen, Marko Kosunen, Kalle Spoof, Mahwish Zahra, Kari Stadius, Vishnu Unnikrishnan |
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Přispěvatelé: | Jussi Ryynänen Group, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University |
Rok vydání: | 2020 |
Předmět: |
Beamforming
radio receiver Phased array Computer science spatial filtering Local oscillator CMOS 020208 electrical & electronic engineering Bandwidth (signal processing) 020206 networking & telecommunications Analog beamforming 02 engineering and technology true-time-delay True time delay RF sampling hybrid beamforming re-sampling 0202 electrical engineering electronic engineering information engineering Electronic engineering Polyphase system phased array Radio frequency Electrical and Electronic Engineering Wideband beam squint |
Zdroj: | IEEE Transactions on Circuits and Systems I: Regular Papers. 67:4457-4469 |
ISSN: | 1558-0806 1549-8328 |
Popis: | openaire: EC/H2020/704947/EU//ADVANTAG5 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. |
Databáze: | OpenAIRE |
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