Eight-channel microwave photonics transceiver photonic integrated circuit

Microwave photonics(MWP)studies the interaction between microwaves and light waves,including the generation,transmission,and processing of microwave signals.Integrated MWP using photonic integrated circuits(PICs)can achieve compact,reliable,and green implementation.However,most PICs have recently been developed that only contain one or a few devices.Here,we propose a multi-channel PIC that covers almost all devices in MWP.Our PIC integrates lasers,modulators,amplifiers,and detectors in the module,successfully manufacturing an eight-channel array transceiver module.We conducted performance tests on the encapsulated transceiver module and found that the cascaded bandwidth of the eightchannel transceiver module was greater than 40 GHz,and the spurious-free dynamic range(SFDR)of the broadband array receiver module was greater than 94 dBm·Hz2/3.The noise figure(NF)is less than-35 dB and the link gain is greater than-26 dB.The success of multi-channel PIC marks a crucial step forward in the implementation of large-scale MWP.

Photonic microwave true time delays for phased array antennas using a 49 GHz FSR integrated optical micro-comb source[Invited]

We demonstrate significantly improved performance of a microwave true time delay line based on an integrated optical frequency comb source. The broadband micro-comb(over 100 nm wide) features a record low free spectral range(FSR) of 49 GHz, resulting in an unprecedented record high channel number(81 over the C band)—the highest number of channels for an integrated comb source used for microwave signal processing. We theoretically analyze the performance of a phased array antenna and show that this large channel count results in a high angular resolution and wide beam-steering tunable range. This demonstrates the feasibility of our approach as a competitive solution toward implementing integrated photonic true time delays in radar and communications systems.

A broadband integrated microwave photonic mixer based on balanced photodetection

An integrated microwave photonic mixer based on silicon photonic platforms is proposed,which consist of a dual-drive Mach–Zehnder modulator and a balanced photodetector.The modulated optical signals from microwave photonic links can be directly demodulated and down-converted to intermediate frequency(IF)signals by the photonic mixer.The converted signal is obtained by conducting of-chip subtraction of the outputs from the balanced photodetector,and subsequent fltering of the high frequency items by an electrical low-pass flter.Benefting from balanced detection,the conversion gain of the IF signal is improved by 6 dB,and radio frequency leakage and common-mode noise are suppressed signifcantly.System-level simulations show that the frequency mixing system has a spurious-free dynamic range of 89 dB·Hz^(2/3),even with deteriorated linearity caused by the two cascaded modulators.The spur suppression ratio of the photonic mixer remains higher than 40 dB when the IF varies from 0.5 to 4 GHz.The electrical-electrical 3 dB bandwidth of frequency conversion is 11 GHz.The integrated frequency mixing approach is quite simple,requiring no extra optical flters or electrical 90°hybrid coupler,which makes the system more stable and with broader bandwidth so that it can meet the potential demand in practical applications.

Recent advances in microwave photonics

Microwave photonics （MWP） is an interdisci- plinary field that combines two different areas of microwave engineering and photonics. It has several key features by transferring signals between the optical domain and microwave domain, which leads to the advantages of broad operation bandwidth for generation, processing and distribution of microwave signals and high resolution for optical spectrum measurement. In this paper, we comprehensively review past and current status of MWP in China by introducing the representative works from most of the active MWP research groups. Future prospective is also discussed fi＇om the national strategy to key enabling technology that we have developed.

Photonic radio frequency channelizers based on Kerr optical micro-combs

We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.This approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.

基于薄膜铌酸锂的微波光子雷达芯片

微波光子雷达拥有分辨率高、处理速度快、同时多波段、多功能等优势,在航天系统中具有广阔的应用前景。为了满足航天应用对雷达系统体积、质量和功耗的严格要求,集成化已经成为微波光子雷达的重要发展方向。介绍了一款基于薄膜铌酸锂的微波光子雷达芯片,利用该芯片实现了雷达发射信号倍频产生和回波信号去斜接收,并对距离天线不同位置的目标进行了测距实验,得到的测量距离与实际距离基本相同,两者之间的误差小于4 mm。

基于无人机集群的综合一体化告警自卫系统设计

现代战争中,无人机已经成为各大军事强国的重要武器装备之一,可被应用于侦察、目标探测、情报搜集、攻击等多种作战任务中,无人机集群作为无人机发展的新方向,具有作用范围大、灵活性强、战术使用多样化等优点,能够更好地完成在复杂战场环境下的各种任务,大大提高了作战效能。传统的机载告警自卫系统功能较为单一,且智能化程度不够高,极大地限制了载机的作战能力和任务执行能力,并不能满足无人机集群的应用设想。文中基于当前无人机集群的应用方式和环境,提出一种多功能综合一体化的告警自卫系统设计架构,在满足传统告警功能的基础上额外增加了智能化和侦察对抗一体化的功能,并在硬件模块上做了一定的优化调整,基本上可以满足无人机集群的应用规划和设想。

一种新型自封焊小型化光电探测模块

提出了一种基于LTCC陶瓷基板的自封焊小型化光电探测模块,通过LTCC内埋电阻发热快速实现器件的密封。该模块不仅可以支持内部集成多种功能的光电芯片,还可与外部单元实现平面化、表贴式贴装,大幅提升模块安装适配性与可靠性。通过测试,模块在18GHz频率范围内具有高响应度与高平坦度,在体积上相较分立器件缩小了一个数量级,同时模块成本预计可降低一半以上,在机载、星载、弹载等平台的宽带相控阵系统中具有广阔的应用前景。

集成互注入半导体激光器的微波光子学应用

光源是微波光子(microwave photonic,MWP)系统的“发动机”,从根本上决定了系统性能的上限。光注入半导体激光器集聚诸多优势,但离散器件引发的系统集成度低、结构复杂、体积大、稳定性差等弊端明显,大大限制了MWP系统的工程化应用。集成化是解决目前MWP技术实用化等瓶颈问题的关键,轻量级、高性能、多功能的激光器光源是集成MWP系统的关键。基于此,本文综述了近年来集成互注入半导体激光器在高效电光转换、微波信号产生、MWP变频、弱信号探测以及光学频率梳源等MWP应用方面的创新研究,期望为集成MWP系统提供可行的高性能集成光源,推动集成MWP技术的工程化应用尽快实现。

Ultra-high suppression microwave photonic bandstop filters

A bandstop radio frequency(RF)filter can enhance the capabilities of RF communication systems by removing unwanted signal components such as distortion,or interference.In modern cognitive radio systems,frequency agile filters are desired to block interferers with dynamically changing frequencies and powers.These filters should be tunable over a broad frequency range,and they should be capable of suppressing very strong signals with a high resolution.To simultaneously meet these requirements with traditional RF filters are highly challenging.Microwave photonic(MWP),a technology that primary deals with the generation,distribution,and processing of high speed RF signals using photonic techniques and components,is promising for creating frequency agile RF filters.However,traditional MWP filters are lacking the high resolution and peak suppression exhibited by state-ofthe-art RF electrical filters.We recently introduced a new class of MWP notch filter which is free from this limitation.This scheme allowed the creation of anomalously high suppression MWP notch filter from virtually any kind of optical resonance,irrespective of its type(gain or absorption),or its magnitude.This enabled,for the first time,simultaneous optimization of the MWP filter resolution,peak attenuation,and frequency tuning range.In this paper,we present the analysis of notch filter response creation using the novel sideband processing technique.We thenshow the applicability of this technique to a wide range of optical filters.We compare simulated and experimental results of the notch filter response created using three types of optical filter commonly used in MWP signal processing,namely stimulated Brillouin scattering(SBS),an integrated optical ring resonator(ORR),and a phase-shifted fiber Bragg-grating(FBG).

小型化高隔离度平衡光电探测器阵列研究

针对传统微波光子应用平衡光电探测器体积大、集成度低的问题,设计了一种基于光电混合集成封装技术的小型化、高隔离度平衡光电探测器阵列,通过集成多个平衡光电二极管芯片及其偏置与匹配电路,实现了4个独立通道的平衡光电探测功能,每个通道平均体积仅为588 mm3。此外,搭建了测试系统,对平衡光电探测器阵列的性能进行测试。测试结果表明:该平衡光电探测器阵列各个通道的响应度大于0.9 A/W,3 dB带宽约为12 GHz,带宽范围内的通道一致性优于±0.43 dB,共模抑制比大于30 dB,通道隔离度在50 dBc以上,在10 GHz处的饱和输入光功率大于8.4 dBm。

微波光子集成及前沿展望(特邀)

微波光子学是一门融合了微波技术和光子技术的交叉学科,是研究光波和微波在媒质中的相互作用以及在光频域实现微波信号的产生、处理、传输及接收的微波光波融合系统。由于现有的微波光子系统大多由分立器件组成,在体积、功耗、稳定性、成本等方面仍有待提升,因此集成化是微波光子技术发展的必然趋势。文中探讨了微波光子集成技术面临的主要科学与技术问题,总结了该技术的发展现状和前沿研究进展,并对其未来发展前景进行了展望。

微波光子与多学科交叉融合的前景展望(特邀)

微波光子学可借助光电子器件实现微波信号的产生、处理、接收和分配等功能,具有宽带、低传输损耗、轻重量、快速可重构及抗电磁干扰等优势。随着微波光子学的理论方法和技术应用的不断发展,微波光子与多学科交叉融合成为其核心发展方向。文中对微波光子与部分学科交叉融合的现状进行了总结,并对微波光子与激光技术、集成光电子学、量子技术和人工智能等前沿学科的交叉融合进行了展望。

异质集成微波光子器件发展现状

微波光子学利用光子技术实现微波信号的产生、传输、处理及控制,可突破传统微波技术在带宽、传输损耗和抗电磁干扰等方面的瓶颈,提升雷达、电子战等信息系统的综合性能。激光器、电光调制器和光电探测器是微波光子技术中的三种核心光电子器件,其性能对微波光子链路的噪声和动态等指标具有决定性的影响,但基于分立器件的微波光子系统体积、重量较大,难以满足雷达、电子战等系统的阵列化需求,硅基异质集成技术以及高密度低损耗片上光传输互连技术是解决有源器件集成和无源器件集成的关键技术。文章介绍了用于微波光子的硅基激光器、电光调制器、光电探测器和波导的异质集成技术的发展现状,并探讨了集成微波光子技术的发展趋势。

高集成硅基微波光子芯片的研究进展及趋势

随着微波光子技术的发展,在解决传统射频领域无法直接实现的功能方面已经有了很大的成就,同时大大促进了光电子通信技术的发展。然而,微波光子技术仍面临着新的挑战:现有的光通信系统由分立的光/电、电/光等元器件构成,在不断追求更高速率、更大带宽和更强处理能力的通信系统的现状下,要求器件和系统的尺寸更小、功耗更低及抗干扰能力更强。因此,通过硅基集成技术和微波光子技术的结合实现微波光子学系统芯片集成化,从而降低整个系统的成本、缩小尺寸、降低功耗,是微波光子学发展的必然趋势。文章总结了微波光子集成技术和硅基光子器件的发展现状,指出可调谐、可编程的硅基微波光子芯片必将成为军事领域和民用方面发展的关键技术。

一种微波光子探测器组件的封装设计与实现

为实现微波光子系统的高集成度、高可靠性,进行了一种微波光子探测器组件的封装设计与实现。介绍了定制化封装设计思路,选择可伐合金作为壳体材料,采用的卧式贴装方案中选用斜面透镜光纤,给出了封装工艺流程和关键工艺点,最终封装的组件光电耦合效率在68%~79%之间,满足总体指标需求。该组件通过混合集成封装方法,实现了微波芯片与光子芯片在同一封装内的阵列化集成及气密性封装。该组件的封装设计与实现方法,可用于其他微波光子产品,有助于提升光载射频传输系统的集成度与可靠性。

集成光子学微波移相器研究进展

从集成光子学多路、高精度微波移相器在光控相控阵雷达系统中的应用背景出发,探讨了该器件的研究进展和应用前景。

基于微波光子的灵活有效载荷系统研究

目前卫星载荷的设计寿命一般在15年左右,期间通信技术已发生了日新月异的变化。现有多频段、多波束卫星在入轨以后,其单端口的技术状态基本固定,一旦投入使用,针对不同波束业务需求,难以灵活地对卫星工作频率和带宽等资源进行重新分配。针对传统微波技术在多频段通用、可重构的技术瓶颈,探讨宽可调谐本振及分发技术、全光变频技术、光控波束形成技术和射频光交换技术等关键技术在一体化、通用化和在轨可重构卫星转发器方面的潜在应用价值。

新型紧凑硅基电光调制器研究

设计了一种应用于微波光子学的硅基锗硅电吸收调制器。调制器基于Franz-Keldysh电吸收调制效应,通过硅基锗硅的选择外延形貌控制实现了调制器有源区单模传输和较大的限制因子。形貌控制同时可形成三维渐变耦合结构,减小了硅脊形波导与Ge Si有源区波导的输入输出损耗。为了优化电学结构,调制器采用了硅和锗硅并联。设计表明,对于70μm长有源区,调制器消光比为8.4 d B,3 d B带宽50 GHz,同时具有较低的插损3.6 d B。

基于光子谐振环的波束形成网络研究

现代相控阵雷达对小重量、低损耗和低成本持续要求,同时获得宽角扫描时的大即时带宽和无波束偏斜扫描,针对上述要求,对基于微环谐振腔的连续可调的时间延迟网络进行了研究。为了实现最少延迟单元,研究了二进制树形拓扑结构和单边带抑制强度直接调制、双周期群延迟响应直接探测机制。作为特例,对于8单元的一维线阵进行了具体设计。设计结果显示,该网络具有显著的大带宽2 GHz,最大延迟时间400 ps,延迟抖动小于0.15倍的环周延迟。