volume | PIER Journals

Abstract

In this paper, dual-chirped arbitrary microwave waveform has been generated through photonics, incorporated with single dual parallel mach-zehnder modulator (DPMZM) inbuilt mach zehnder interferometer (MZI) structure. We have taken two cases of chirping i.e. linear and nonlinear chirps. A case of linear chirping has been explored previously. However, to the best of the authors' knowledge effect of nonlinear chirping in this paper is evaluated for the first time. Other photonics approaches are also available, such as spectra shaping and wavelength to time mapping. But due to fixed spectral response of spectral shaper, center frequency of linear chirp generated waveform is fixed. To get the large center frequency again we have to use large number of spectral shapers which will increase the system complexity. DPMZM avoids such difficulties. These MZMs are biased at the minimum transmission point to get carrier suppressed modulation. Product modulator (PM) is cascaded to the lower arm of DPMZM. Here by using DPMZM we get two advantages. First we have two complimentarily chirped microwave waveforms and second up conversion of the frequency of microwave carrier. A dual-chirped microwave waveform with centre frequency 6 GHz with bandwidth 200 MHz and 2 GHz is generated. The paper gives specific details about various performance parameters such as input signal frequency and power, output signal parameters viz output frequency, chirp rate, chirp bandwidth, time bandwidth product (TBW), etc. The overall model and its performance parameters are computed through MATLAB simulation.

1. Seeds, A. J., "Microwave photonics," IEEE Trans. Microwave Theory Tech., Vol. 50, No. 3, 877-887, Mar. 2002.
doi:10.1109/22.989971 Google Scholar

2. Seeds, A. J. and K. Williams, "Microwave photonics," J. Lightwave Technol., Vol. 24, No. 12, 4628-4641, Dec. 2006.
doi:10.1109/JLT.2006.885787 Google Scholar

3. Capmany, J. and D. Novak, "Microwave photonics combines two worlds," Nature Photonics, Vol. 1, 319-330, Sep. 2007.
doi:10.1038/nphoton.2007.89 Google Scholar

4. Richards, M. A., Fundamentals of Radar Signal Processing, 2 Ed., McGraw-Hill, New York, NY, USA, 2014.

5. Skolnik, M. I., Introduction to Radar Systems, 2 Ed., McGraw-Hill, New York, NY, USA, 2001.

6. Fitzgerald, R. J., "Effects of range-doppler coupling on chirp radar tracking accuracy," IEEE Trans. Aerosp. Electron. Syst., Vol. 10, No. 4, 528-532, Jul. 1974. Google Scholar

7. Amar, A. and Y. Buchris, "Asynchronous transmitter position and veloc-ity estimation using a dual linear chirp," IEEE Signal Process. Lett., Vol. 21, No. 9, 1078-1082, Sep. 2014.
doi:10.1109/LSP.2014.2321330 Google Scholar

8. Dotan, A. A. and I. Rusnak, "Method of measuring closing velocity by transmitting a dual-chirp signal," Proc. 26th IEEE Conf. Elect. Electron. Eng. Israel, 000258-000262, Eilat, Israel, Nov. 2010. Google Scholar

9. Zhu, D. and J. Yao, "Dual-chirp microwave waveform generation using a dual-parallel Mach- Zehnder modulator," IEEE Photonics Technology Letters, Vol. 27, No. 13, Jul. 1, 2015. Google Scholar

10. Iwashita, K., T. Moriya, N. Tagawa, and M. Yoshizawa, "Doppler measurement using a pair of FM-chirp signals," Proc. IEEE Symp. Ultrason., 1219-1222, Honolulu, HI, USA, Oct. 2003. Google Scholar

11. Middleton, R. J. C., D. G. Macfarlane, and D. A. Robertson, "Range autofocus for linearly frequency-modulated continuous wave radar," IET Radar, Sonar Navigat., Vol. 5, No. 3, 288-295, Mar. 2011.
doi:10.1049/iet-rsn.2010.0097 Google Scholar

12. Weigel, R., et al. "Microwave acoustic materials, devices, and applications," IEEE Trans. Microw. Theory Techn., Vol. 50, No. 3, 738-749, Mar. 2002.
doi:10.1109/22.989958 Google Scholar

13. Panasik, C. M., "Multiple frequency acoustic reflector array and monolithic cover for resonators and method,", U.S. Patent 6 441 703, Aug. 27, 2002. Google Scholar

14. Symons, P., Digital Waveform Generation, Cambridge University Press, New York, NY, USA, 2013.
doi:10.1017/CBO9781139108072

15. Gomez-Garcia, D., C. Leuschen, F. Rodriguez-Morales, J.-B. Yan, and P. Gogineni, "Linear chirp generator based on direct digital synthesis and frequency multiplication for airborne FMCW snow probing radar," Proc. IEEE MTT-S Int. Microw. Symp. (IMS), 1-4, Tampa, FL, USA, Jun. 2014. Google Scholar

16. Yao, J., "Photonic generation of microwave arbitrary waveforms," Opt. Commun., Vol. 284, No. 15, 3723-3736, Jul. 2011.
doi:10.1016/j.optcom.2011.02.069 Google Scholar

17. Khan, M. H., et al. "Ultrabroad-bandwidth arbitrary radiofrequency waveform generation with a silicon photonic chip-based spectral shaper," Nature Photon., Vol. 4, 117-122, Feb. 2010.
doi:10.1038/nphoton.2009.266 Google Scholar

18. Kanno, A. and T. Kawanishi, "Broadband frequency-modulated continuous-wave signal generation by optical modulation technique," J. Lightw. Technol., Vol. 32, No. 20, 3566-3572, Oct. 15, 2014.
doi:10.1109/JLT.2014.2318724 Google Scholar

19. Yao, T., D. Zhu, S. Liu, F. Zhang, and S. Pan, "Wavelength-division multiplexed fiber-connected sensor network for source local-ization," IEEE Photon. Technol. Lett., Vol. 26, No. 18, 1874-1877, Sep. 15, 2014. Google Scholar

20. Li, W. and J. P. Yao, "Microwave frequency multiplication using two cascaded Mach-Zehnder modulators," Proc. 2009 Asia-Pacific Microwave Photonics Conf., Beijing, China, Apr. 2009. Google Scholar

21. Li, W. and J. P. Yao, "Investigation of photonically assisted microwave frequency multiplication based on external modulation," IEEE Trans. Microw. Theory Tech., Vol. 58, No. 11, 3259-3268, Nov. 2010.
doi:10.1109/TMTT.2010.2075671 Google Scholar

Dr. Sanjeev Kumar Raghuwanshi

Dr. Ritesh Kumar

Dr. Nimish Kumar Srivastava