# 级联IIR和FIR滤波器的微波光子滤波器的特性分析The Characteristic Analysis of Microwave Photonic Filter Using Cascaded IIR Filter and FIR Filter

• 全文下载: PDF(1542KB)    PP.48-55   DOI: 10.12677/OE.2019.91008
• 下载量: 183  浏览量: 269   科研立项经费支持

Based on the thorough research of the technology of microwave filtering, a kind of microwave photonic filter (MPF) using cascaded IIR filter and FIR filter was theoretically analyzed. And the influences of the coupling coefficient of the IIR filter, the gain of Er-doped fiber ring, the reflectivity of the fiber Bragg gratings (FBGs), and the coupling coefficient of the FIR filter on the filtering performance of the MPF were discussed. The results show that the intermodulation of band pass and band stop filtering can be achieved by optimizing the coupling coefficient of the FIR filter, the coupling coefficient, the gain of Er-doped fiber ring and the reflectivity of FBGs of the IIR filter.

1. 引言

2. 级联IIR滤波器和FIR滤波器的MPF的结构和滤波原理

Figure 1. The structure diagram of the microwave photonic filter based on cascaded IIR filter and FIR filter

3. 分析和讨论

Figure 2. The signal flow diagram of the microwave photonic filter based on cascaded IIR filter and FIR filter

$H\left(\omega \right)=\left[\frac{\left(1-{k}_{1}\right){\text{e}}^{j\omega T}-\left(2{k}_{1}-1\right)\left(1-{k}_{1}\right){R}^{2}{g}^{2}}{{\text{e}}^{j\omega T}-{R}^{2}{g}^{2}{\left(1-{k}_{1}\right)}^{2}}\right]\left[{k}_{2}-\left(1-{k}_{2}\right){\text{e}}^{j\omega T}\right]$

$z={\text{e}}^{j\omega T}={\text{e}}^{j2\pi fT}$$f$ 是微波信号的基波频率， $T=\frac{2nL}{c}$ 是光信号在光纤环中的延迟时间， $n$ 为光纤环的

3.1. IIR滤波器中耦合器的耦合系数k1对MPF滤波性能的影响

3.2. FIR滤波器中耦合器的耦合系数k2对MPF滤波性能的影响

Figure 3. The effect of coupling coefficient k1 with IIR filter on the performance of the microwave photonic filter

Figure 4. The effect of coupling coefficient k2 with FIR filter on the performance of the microwave photonic filter

3.3. IIR滤波器中的掺饵光纤环的增益g对MPF滤波性能的影响

Figure 5. The effect of the gain of the erbium-doped fiber on the performance of the microwave photonic filter

3.4. IIR滤波器中FBGs的反射率R对MPF滤波性能的影响

3.5. 掺饵光纤环的长度L对MPF滤波性能的影响

3.6. 平坦带阻MPF的实现

Figure 6. The effect of the reflectivity of the fiber Bragg grating on the performance of the microwave photonic filter

Figure 7. The effect of the length of the fiber ring on the performance of the microwave photonic filter

4. 结束语

Figure 8. The effect of coupling coefficient k2 with FIR filter on the performance of the bandstop microwave photonic filter

 [1] Capmany, J., Mora, J., Gasulla, I., et al. (2013) Microwave Photonic Signal Processing. Journal of Light Wave Technology, 31, 571-586. https://doi.org/10.1109/JLT.2012.2222348 [2] Minasian, R.A. (2006) Photonic Signal Processing of Microwave Signals. IEEE Transactions on Microwave Theory and Techniques, 54, 832-846. https://doi.org/10.1109/TMTT.2005.863060 [3] Capmanyj, N.D. (2007) Microwave Photonics Combines Two Worlds. Nature Photonics, 1, 319-330. [4] Dolfi, D. (2011) New Trends in Optoelectronics for Radar, EW and Communication Systems. IEEE International Topical Meeting on Microwave Photonics, Singapore. [5] Liu, J., Guo, N., Li, Z., et al. (2013) Ultrahigh-Q Microwave Photonic Filter with Tunable Q Value Utilizing Cascaded Optical-Electrical Feedback Loops. Optics Letters, 38, 4304-4307. https://doi.org/10.1364/OL.38.004304 [6] Capmany, J., Pastor, D. and Ortega, B. (1999) New and Flexible Fiber-Optic Delay-Line Filters Using Chirped Bragg Grattings and Laser Arrays. IEEE Transactions on Microwave theory and Techniques, 47, 1321-1326. https://doi.org/10.1109/22.775473 [7] Hamidi, E., Leaird, D.E. and Weiner, A.M. (2010) Tunable Programmable Microwave Photonic Fitlers Based on Anoptical Frequency Comb. IEEE Transactions on Microwave theory and Techniques, 58, 3269-3278. https://doi.org/10.1109/TMTT.2010.2076970 [8] Zhangy, P.S. (2013) Tunable Multitap Microwave Photonic Filter with All Complex Coefficients. Optics Letters, 38, 802-804. https://doi.org/10.1364/OL.38.000802 [9] Wang, Q. and Yao, J.P. (2008) Multitap Photonic Microwave Filters with Arbitrary Positive and Negative Coefficients Using a Polarization Modulator and an Optical Polarizer. IEEE Photonics Technology Letters, 20, 78-80. https://doi.org/10.1109/LPT.2007.912562 [10] Manzanedo, M.D., Mora, J. and Campmany, J. (2008) Continuously Tunable Microwave Photonic Filter with Negative Coefficients Using Cross-Phase Modulation in an SOA-MZ Interferometer. IEEE Photonics Technology Letters, 20, 526-528. https://doi.org/10.1109/LPT.2008.918884 [11] Zeng, F., Wang, J. and Yao, J. (2005) All-Optical Microwave Bandpass Filter with Negative Coefficients Based on a Phase Modulator and Linearly Chirped Fiber Bragg Gratings. Optics Letters, 30, 2203-2205. https://doi.org/10.1364/OL.30.002203 [12] Yan, Y. and Yao, J. (2007) A Tunable Photonic Microwave Filter with a Complex Coefficient Using an Optical RF Phaseshifter. IEEE Photonics Technology Letters, 19, 1472-1474. https://doi.org/10.1109/LPT.2007.903753 [13] Qi, C.H., Pei, L., Ning, T.G., et al. (2010) Flat Microwave Photonic Filter Based on Hybrid of Two Filters. Journal of Optics, 12, Article ID: 055402.