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基于微环谐振腔和光纤布拉格光栅,利用相位-强度调制,实现了三种滤波响应可切换微波光子滤波器。通过改变光纤布拉格光栅反射谱、微环谐振腔陷波和光载波三者之间的相对波长,微波光子滤波器的滤波响应可以在带通、平顶带通和高通之间切换。制备了欧拉微环并搭建了微波光子滤波器系统,实现了上述三种响应。三种响应的带宽均具有一定的调谐能力,其调谐范围分别为5.56~7.68 GHz、6.23~11.92 GHz和5.83~10.86 GHz。三种响应下微环的插入损耗均小于10 dB。可切换的滤波响应使该微波光子滤波器具有更高的灵活性,在频率测量、杂散抑制等场景中具有广阔的应用空间。 相似文献
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基于单片微波集成电路技术设计了一款S波段频率可调谐滤波器芯片,该可调谐滤波器芯片采用信道化结构,通过选择不同通道实现宽调谐比。其中每个通道采用多级放大器与无源滤波网络级联的形式提高该滤波电路的选择性,通过在无源滤波网络引入变容二极管实现通道频率的连续调谐,该结构可在滤波器具备较高选择性的前提下实现宽调谐比。采用0.25 μm GaAs 赝配高电子迁移率晶体管(PHEMT)工艺设计了一款S波段双通道信道化可重构滤波器,仿真结果表明,在0~3 V控制电压范围下,该滤波器中心频率调谐范围为2.5~4 GHz,带宽变化范围为420~650 MHz,调谐比达到60%,滤波器芯片尺寸为3 mm×3.1 mm。该设计为片上可重构射频滤波实现宽频率调谐比提供了一条技术途径。 相似文献
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针对负系数微波光子滤波器很难用正系数的光学抽头来实现,提出了一款基于色散器件级联的可调谐、窄带宽、负系数微波光子滤波器。利用整形后的多波长光纤激光器的输出信号作为滤波器的抽头光源,将单模光纤与F-P光纤环级联作为延迟单元,实现滤波器的频率选择性。利用相位调制器和级联的色散器件共同作用,实现负系数的微波光子滤波器。实验得到了波长间隔为0.34 nm的多达37个激光信号的稳定输出,进而基于此实验结果仿真研究了F-P光纤环中C2、C3的耦合系数r、不同长度的可调谐光纤延迟线(TODL)和延迟单元中不同长度的单模光纤等参数对微波光子滤波器性能的影响。 相似文献
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基于偏振调制器(PolM)设计并实现具有可变系数特 性的可调谐微波光子滤波器,通过理论计算与实验证 实了设计方案的可行性。PolM可以对输入的微波信号实现两路正交反相的相位调 制,经强度调制转 换后,可以拍频恢复出原来的微波信号。仅需通过调节偏振控制器(PC)控制光信号的检偏方 向,即可实现恢复 出的微波信号π相位变化,进而实现滤波器抽头系数的正负变化。利用偏振分束器(PBS)实 现两路光信号检偏和 合并的同时,能够有效地避免两路光信号之间的干涉。通过调节光路中的光可调时延线(OTD L)改变两路光信号 间的时延差,能够改变滤波器的自由光谱范围(FSR),实现滤波 器的可调谐。通过实验验证了时延差分别为300ps和400ps 两种情况下正系数和负系数微波光子滤波器的频率响应,与理论计算值相吻合,验证了方案 正确性。 相似文献
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一种新型可调谐光子晶体滤波器的理论研究 总被引:8,自引:1,他引:7
建立了可调谐光子晶体滤波器的设计标准,作为设计的依据.通过数值计算和理论分析,得出了一维掺杂光子晶体的缺陷模随杂质光学厚度L和光子晶体折射率n2的变化特征.设计出的可调谐一维光子晶体滤波器在理论上能很好地满足设计标准,滤波通道的半高宽(FWHM)可调范围在1~4 nm间,波长λ可调范围达300 nm,透射率峰值大于0.95. 相似文献
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将铁电液晶作为缺陷层引入一维光子晶体中,基于液晶的电控双折射,形成快速窄带调谐滤波器.用传输矩阵法研究了铁电液晶缺陷光子晶体的可调谐滤波特性,计算了电场对滤波器透射峰的位置、强度、个数和带宽的影响,结果表明该滤波器呈现良好的滤波功能. 相似文献
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A novel approach for the implementation of microwave photonic filter with positive and negative coefficients based on an unbalanced Mach-Zehnder modulator(MZM) is proposed.In the proposed filter,a microwave signal to be filtered is applied to an unbalanced MZM.Thanks to the unbalance between the two arms of the modulator,a π phase shift is obtained by adjusting the wavelength interval between the adjacent wavelengths,which leads to the generation of the positive and negative coefficients.The theoretical fundamentals of the design are described,which show that the required unbalanced MZM in the scheme can be well fabricated by the current technology,and the required other components,including the wavelength multiplexer,are also commercially available devices.An eight-tap microwave photonic filter with positive and negative coefficients is demonstrated.The tunability and reconfigurability of the eight-tap microwave photonic filter are also investigated to verify our approach. 相似文献
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Reconfigurable Microwave Photonic Filter Using Multiwavelength Erbium-Doped Fiber Laser 总被引:1,自引:0,他引:1
Xinhuan Feng C. Lu H.Y. Tam P.K.A. Wai 《Photonics Technology Letters, IEEE》2007,19(17):1334-1336
A microwave photonic filter using a simple and novel multiwavelength erbium-doped fiber laser (EDFL) is proposed. The filter was experimentally demonstrated featuring tunability and reconfigurability by adjustment of the output from the EDFL. The experimental results show excellent agreement with the numerical simulations. 相似文献
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低相位噪声微波信号在通信、雷达、时频计量、深空探测等领域中不可或缺,光子学微波信号产生近年来发展快速,有望在载波频率、调谐性、相噪、可集成、功耗等多个方面突破传统电子学微波信号产生瓶颈。早期的光生微波系统复杂,激光器以及相关稳定设备体积庞大,难以在实验室以外的场所应用。近年来,基于微谐振腔的光学频率梳的迅速发展,凭借其低损耗、小体积、强稳定的优势,基于微腔光梳的微波光子学应用吸引了研究者们的广泛关注,其中基于微腔光梳的光生微波系统得到深入研究。文中将综述国内外近10年来基于微腔光梳的低相噪微波信号产生发展状况,并对基于微腔光梳的光生微波系统在未来应用中的主要挑战与发展趋势作以展望。 相似文献
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This paper first presents the fundamental principles of the microwave photonic filters.As an example to explain how to implement a microwave photonic filter, a specific finite impulse response (FIR) filter is illustrated.Next, the Q value of the microwave photonic filters is analyzed theoretically, and methods around how to gain high Q value are discussed.Then,divided into FIR filter, first-order infinite impulse response (IIR) filter, and multi-order IIR filter, several novel microwave photonic filters with high Q value are listed and compared.The technical difficulties to get high Q value in first-order IIR filter and multi-order IIR filter are analyzed concretely.Finally, in order to gain higher Q value, a multi-order IIR microwave photonic filter that easily extends its order is presented and discussed. 相似文献
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A new microwave photonic filter structure realising fully programmable RF filtering that can tune the filter centre frequency and also reconfigure the filter shape, while exhibiting multiple taps and bipolar taps, is presented. It is based on a new arbitrary spectrum slicing technique using a multi-port programmable wavelength processor, based on liquid crystal on silicon pixels, which offers programmable finite impulse response filtering using software control. Experimental results demonstrate a high-order microwave filter with tunability, reconfigurability, bipolar taps, and with high free spectral range. 相似文献
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A continuously tunable photonic microwave bandpass filter with positive and negative coefficients implemented using an optical phase modulator and chirped fiber Bragg gratings (FBGs) is proposed and experimentally demonstrated. The positive and negative coefficients are generated through optical phase-modulation to intensity-modulation conversion by reflecting the phase-modulated optical carrier from linearly chirped FBGs (LCFBGs) with positive and negative dispersions. The tunability of the filter is realized by changing the wavelength of the optical carrier such that it is reflected at different physical locations in the LCFBGs. A two-tap microwave bandpass filter with a free spectral range tunable from 1.14 to 4.55 GHz is experimentally demonstrated. 相似文献
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We have demonstrated a tapped delay line microwave filter based on the use of high dispersion fiber as the tunable time delay. This system offers advantages of high bandwidth and tunability over current methods of time delay filtering 相似文献
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基于可调谐真相移的可调谐光电振荡器 总被引:3,自引:3,他引:0
提出一种基于真相移(TPS)实现可调谐光电振荡器( OEO)的方案。只需通过调谐Mach-Zehnder 调制器(MZM)的偏置电压,就可以实现可谐滤波器的频谱响应的改变,即可实现TPS滤波器。 其中,两个抽头的可调谐滤波器是由双光源、双调制器以及叠印光栅来实现。OEO的输出频 率由二抽头可调 谐滤波器的峰值频率决定,而滤波器可调谐,这样就可以实现输出OEO的输出频率可调。 仿真结果表明,输出频率可以实现5~10GHz宽带宽可调谐。 相似文献
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A tunable microwave photonic bandpass filter with high mainlobe-to-sidelobe ratio (MSR) based on a phase modulator and a dispersive device is proposed. The multi-tap characteristics of the filter are realized by slicing a broadband source using a Mach-Zehnder interferometer (MZI) which results in a high MSR of 25 dB. The tunability of the filter is realized by an optical variable delay line (OVDL) in one arm of the MZI, which changes the wavelength spacing of the sliced broadband source and results in a tunable free spectrum range (FSR) of the filter. The central frequency of the bandpass filter is tunable from 10.7 GHz to 27 GHz by changing the wavelength spacing from 0.145 nm to 0.054 nm. 相似文献