Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics

Xiangzhi Xie; Hanke Feng; Yuansheng Tao; Yiwen Zhang; Yikun Chen; Ke Zhang; Zhaoxi Chen; Cheng Wang

doi:10.23919/emsci.2024.0046

Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics

Xiangzhi Xie^* (Co-first Author), Hanke Feng (Co-first Author), Yuansheng Tao, Yiwen Zhang, Yikun Chen, Ke Zhang, Zhaoxi Chen, Cheng Wang^*

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

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Abstract

Frequency mixers are fundamental components in modern wireless communication and radar systems, responsible for up- and down-conversion of target radio-frequency (RF) signals. Recently, photonic-assisted RF mixers have shown unique advantages over traditional electronic counterparts, including broad operational bandwidth, flat frequency response, and immunity to electromagnetic interference. However, current integrated photonic mixers face significant challenges in achieving efficient conversion at high frequencies, especially in millimeter-wave bands, due to the limitations of existing electro-optic (EO) modulators. Additionally, high-frequency local oscillators (LOs) in the millimeter-wave range are often difficult to obtain and expensive, leading to unsatis-factory cost and restricted operational bandwidth in practice. In this paper, we harness the exceptional EO property and scalability of thin-film lithium niobate (TFLN) photonic platform to implement a high-performance harmonic-reconfigurable millimeter-wave mixer. The TFLN photonic circuit integrates a broadband EO modulator that allows for extensive frequency coverage, and an EO frequency comb source that significantly reduces the required carrier frequency of the LO. We experimentally demonstrate fully re-configurable frequency down-conversion across a broad operational bandwidth ranging from 20 GHz to 67 GHz, with a large intermediate frequency of 20 GHz, as well as up-conversion to frequencies up to 110 GHz. Our integrated photonic mixing system shows dramatically improved bandwidth performance, along with competitive frequency conversion efficiency and spurious suppression ratio, positioning it as a promising solution for future millimeter-wave transceivers in next-generation communication and sensing systems.

© 2025 The Author(s)

Original language	English
Article number	0090462
Pages (from-to)	0090462-1-0090462-10
Journal	Electromagnetic Science
Volume	3
Issue number	1
DOIs	https://doi.org/10.23919/emsci.2024.0046
Publication status	Published - Mar 2025

Funding

This work was supported by the Research Grants Council, University Grants Committee (Grant Nos. CityU 11212721, CityU 11204022, C1002-22Y, and N_CityU113/20), the Croucher Foundation (Grant No. 9509005), and City University of Hong Kong (Grant No. 9610682). The authors would like to thank the technical support of Mr. Chun Fai Yeung, Ms. Chan Olive, Mr. C. W. Lai, and Mr. Li Ho at the Nanosystem Fabrication Facility (NFF), Hong Kong University of Science and Technology, Hong Kong, China, for the stepper lithography and PECVD process. They thank Dr. Wing-Han Wong and Dr. Keeson Shum at City University of Hong Kong, Hong Kong, China, for their help in measurement and device fabrication.

Research Keywords

Integrated microwave photonics
Thin-film lithium niobate
Millimeter-wave frequency mixing

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This full text is made available under CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/

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10.23919/emsci.2024.0046

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YCRG: Large-scale Lithium Niobate Photonic Integrated Circuits for Neuromorphic Computing
WANG, C. (Principal Investigator / Project Coordinator), HUANG, C. (Co-Principal Investigator), LIU, Y. (Co-Principal Investigator) & PUN, K. P. (Co-Principal Investigator)
1/06/23 → …
Project: Research
GRF: An Integrated Millimeter-wave Photonic Phased Array Receiver System
WANG, C. (Principal Investigator / Project Coordinator) & CHAN, C. H. (Co-Investigator)
1/01/23 → …
Project: Research
GRF: Programmable On-chip Electro-optic Frequency Comb Generation for DWDM Applications
WANG, C. (Principal Investigator / Project Coordinator)
1/01/22 → …
Project: Research

Cite this

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title = "Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics",

abstract = "Frequency mixers are fundamental components in modern wireless communication and radar systems, responsible for up- and down-conversion of target radio-frequency (RF) signals. Recently, photonic-assisted RF mixers have shown unique advantages over traditional electronic counterparts, including broad operational bandwidth, flat frequency response, and immunity to electromagnetic interference. However, current integrated photonic mixers face significant challenges in achieving efficient conversion at high frequencies, especially in millimeter-wave bands, due to the limitations of existing electro-optic (EO) modulators. Additionally, high-frequency local oscillators (LOs) in the millimeter-wave range are often difficult to obtain and expensive, leading to unsatis-factory cost and restricted operational bandwidth in practice. In this paper, we harness the exceptional EO property and scalability of thin-film lithium niobate (TFLN) photonic platform to implement a high-performance harmonic-reconfigurable millimeter-wave mixer. The TFLN photonic circuit integrates a broadband EO modulator that allows for extensive frequency coverage, and an EO frequency comb source that significantly reduces the required carrier frequency of the LO. We experimentally demonstrate fully re-configurable frequency down-conversion across a broad operational bandwidth ranging from 20 GHz to 67 GHz, with a large intermediate frequency of 20 GHz, as well as up-conversion to frequencies up to 110 GHz. Our integrated photonic mixing system shows dramatically improved bandwidth performance, along with competitive frequency conversion efficiency and spurious suppression ratio, positioning it as a promising solution for future millimeter-wave transceivers in next-generation communication and sensing systems.{\textcopyright} 2025 The Author(s)",

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year = "2025",

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doi = "10.23919/emsci.2024.0046",

language = "English",

volume = "3",

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Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics. / Xie, Xiangzhi (Co-first Author); Feng, Hanke (Co-first Author); Tao, Yuansheng et al.
In: Electromagnetic Science, Vol. 3, No. 1, 0090462, 03.2025, p. 0090462-1-0090462-10.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics

AU - Xie, Xiangzhi

AU - Feng, Hanke

AU - Tao, Yuansheng

AU - Zhang, Yiwen

AU - Chen, Yikun

AU - Zhang, Ke

AU - Chen, Zhaoxi

AU - Wang, Cheng

PY - 2025/3

Y1 - 2025/3

N2 - Frequency mixers are fundamental components in modern wireless communication and radar systems, responsible for up- and down-conversion of target radio-frequency (RF) signals. Recently, photonic-assisted RF mixers have shown unique advantages over traditional electronic counterparts, including broad operational bandwidth, flat frequency response, and immunity to electromagnetic interference. However, current integrated photonic mixers face significant challenges in achieving efficient conversion at high frequencies, especially in millimeter-wave bands, due to the limitations of existing electro-optic (EO) modulators. Additionally, high-frequency local oscillators (LOs) in the millimeter-wave range are often difficult to obtain and expensive, leading to unsatis-factory cost and restricted operational bandwidth in practice. In this paper, we harness the exceptional EO property and scalability of thin-film lithium niobate (TFLN) photonic platform to implement a high-performance harmonic-reconfigurable millimeter-wave mixer. The TFLN photonic circuit integrates a broadband EO modulator that allows for extensive frequency coverage, and an EO frequency comb source that significantly reduces the required carrier frequency of the LO. We experimentally demonstrate fully re-configurable frequency down-conversion across a broad operational bandwidth ranging from 20 GHz to 67 GHz, with a large intermediate frequency of 20 GHz, as well as up-conversion to frequencies up to 110 GHz. Our integrated photonic mixing system shows dramatically improved bandwidth performance, along with competitive frequency conversion efficiency and spurious suppression ratio, positioning it as a promising solution for future millimeter-wave transceivers in next-generation communication and sensing systems.© 2025 The Author(s)

AB - Frequency mixers are fundamental components in modern wireless communication and radar systems, responsible for up- and down-conversion of target radio-frequency (RF) signals. Recently, photonic-assisted RF mixers have shown unique advantages over traditional electronic counterparts, including broad operational bandwidth, flat frequency response, and immunity to electromagnetic interference. However, current integrated photonic mixers face significant challenges in achieving efficient conversion at high frequencies, especially in millimeter-wave bands, due to the limitations of existing electro-optic (EO) modulators. Additionally, high-frequency local oscillators (LOs) in the millimeter-wave range are often difficult to obtain and expensive, leading to unsatis-factory cost and restricted operational bandwidth in practice. In this paper, we harness the exceptional EO property and scalability of thin-film lithium niobate (TFLN) photonic platform to implement a high-performance harmonic-reconfigurable millimeter-wave mixer. The TFLN photonic circuit integrates a broadband EO modulator that allows for extensive frequency coverage, and an EO frequency comb source that significantly reduces the required carrier frequency of the LO. We experimentally demonstrate fully re-configurable frequency down-conversion across a broad operational bandwidth ranging from 20 GHz to 67 GHz, with a large intermediate frequency of 20 GHz, as well as up-conversion to frequencies up to 110 GHz. Our integrated photonic mixing system shows dramatically improved bandwidth performance, along with competitive frequency conversion efficiency and spurious suppression ratio, positioning it as a promising solution for future millimeter-wave transceivers in next-generation communication and sensing systems.© 2025 The Author(s)

KW - Integrated microwave photonics

KW - Thin-film lithium niobate

KW - Millimeter-wave frequency mixing

U2 - 10.23919/emsci.2024.0046

DO - 10.23919/emsci.2024.0046

M3 - RGC 21 - Publication in refereed journal

SN - 2836-9440

VL - 3

SP - 0090462-1-0090462-10

JO - Electromagnetic Science

JF - Electromagnetic Science

IS - 1

M1 - 0090462

ER -

Broadband Millimeter-Wave Frequency Mixer Based on Thin-Film Lithium Niobate Photonics

Abstract

Funding

Research Keywords

Publisher's Copyright Statement

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Projects

YCRG: Large-scale Lithium Niobate Photonic Integrated Circuits for Neuromorphic Computing

GRF: An Integrated Millimeter-wave Photonic Phased Array Receiver System

GRF: Programmable On-chip Electro-optic Frequency Comb Generation for DWDM Applications

Cite this