A True Time Delay-based SiGe Bi-directional T/R Chipset for Large-Scale Wideband Timed Array Antennas

Cho, Moon-Kyu; Song, Ickhyun; Cressler, John D.

doi:10.1109/rfic.2018.8428977

Cited by 34 publications

(18 citation statements)

References 5 publications

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“…Delays can be introduced by transmission line[12]. But a more promising approach is to use digitally controlled analog circuits to apply delay either in RF[14] or baseband[15].…”

mentioning

confidence: 99%

Wideband Millimeter-Wave Beam Training with True-Time-Delay Array Architecture

Han

Boljanovic

Čabrić

2019

2019 53rd Asilomar Conference on Signals, Systems, and Computers

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Millimeter-wave communications rely on beamforming gain from both transmitters and receivers to compensate for severe propagation loss. To achieve adequate gain, beam training is required to identify propagation directions. The main challenge in beam training arises from maintaining low overhead with increased array size. This paper presents a novel one-shot beam training technique that utilizes the emerging architecture of true-time-delay (TTD) arrays. We first show that TTD arrays facilitate frequency dependent beam steering. The proposed training procedure with TTD arrays then exploits this fact by using a single radio-frequency-chain to multiplex different subcarriers into different sounding directions. We derive conditions on the parameters of TTD array configuration and physical layer to achieve scanning of the entire angular domain with a single orthogonal frequency-division multiplexing (OFDM) training symbol. The estimation of propagation directions with high resolution is achieved via low-complexity digital signal processing of spatially coded subcarriers. Simulation results show that this TTD array based approach requires an order-ofmagnitude fewer training symbols than those of phased arrays.

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“…Delays can be introduced by transmission line[12]. But a more promising approach is to use digitally controlled analog circuits to apply delay either in RF[14] or baseband[15].…”

mentioning

confidence: 99%

Wideband Millimeter-Wave Beam Training with True-Time-Delay Array Architecture

Han

Boljanovic

Čabrić

2019

2019 53rd Asilomar Conference on Signals, Systems, and Computers

View full text Add to dashboard Cite

show abstract

“…The result shows that the polyphase structure allows the pulse-skipped LOs without an increase in NF. Table I summarizes the measured performance of the prototype, and compares it to the state-of-the-art [5]- [8]. The proposed true-time-delay front-end provides the widest reported frequency range of 0.6-4.0 GHz, which is realized without area-consuming inductors.…”

Section: B Receiver Prototypementioning

confidence: 99%

“…Our implementation offers several improvements over published true-time-delay beamforming solutions [5]- [9]. The proposed RF-resampling TTD method is the only one published, which scales the delays with f c .…”

Section: Introductionmentioning

confidence: 99%

A 0.6–4.0 GHz RF-Resampling Beamforming Receiver With Frequency-Scaling True-Time-Delays up to Three Carrier Cycles

Spoof

Zahra

Unnikrishnan

et al. 2020

IEEE Solid-State Circuits Lett.

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True-time-delays enable wideband analog and hybrid beamforming by mitigating the beam squint problem. This paper reports a true-time-delay beamforming receiver supporting delays up to three carrier-frequency cycles. The implementation is the first published work in which the delays scale with the carrier frequency. The scaling enables true-time-delays for large arrays at low-GHz frequencies where long delays are required due to λc/2 antenna spacing. The delays are implemented through delayed resampling of a passive mixer's discrete-time output. Driving the mixers with pulse-skipped local oscillator (LO) signals allows the delay range to exceed one carrier cycle. A polyphase receiver structure prevents aliasing of noise and unwanted tones caused by LO pulse-skipping. Our prototype implementation demonstrates squint-free beamforming for an 800 MHz instantaneous RF bandwidth. The proposed true-timedelay is efficient for large arrays since the power consumption per antenna is only 5-13 mW across the 0.6-4.0 GHz frequency range. The prototype was implemented in 28-nm FD-SOI CMOS, and the die area including bonding pads is only 1.2 mm 2 .

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“…The published TTD elements for beamforming mainly fit two categories, passive and active. The passive solutions are based on LC delay lines [16], [17] or transmission lines [24]. The passive TTD elements support wide frequency ranges up to tens of GHz.…”

Section: Prior Art Of Integrated Analog Domain Ttd Elementsmentioning

confidence: 99%

“…Several TTD elements for wideband analog beamforming have been published. Elements based on delay lines, [16], [17], require inductors and hence large area. Active all-pass filter based TTD solutions [18]- [20] have high power consumption and limited operating frequencies.…”

mentioning

confidence: 99%

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

Spoof

Unnikrishnan

Zahra

et al. 2020

IEEE Trans. Circuits Syst. I

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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-timedelay beamforming receiver architecture which enables squintfree 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.

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A True Time Delay-based SiGe Bi-directional T/R Chipset for Large-Scale Wideband Timed Array Antennas

Cited by 34 publications

References 5 publications

Wideband Millimeter-Wave Beam Training with True-Time-Delay Array Architecture

Wideband Millimeter-Wave Beam Training with True-Time-Delay Array Architecture

A 0.6–4.0 GHz RF-Resampling Beamforming Receiver With Frequency-Scaling True-Time-Delays up to Three Carrier Cycles

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

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