Journal of Electrical Engineering and Technology

The Korean Institute of Electrical Engineers (대한전기학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Study on Frequency Up-conversion in USPR using MATLAB

  • Roh, Young-Su (Dept. of Electrical and Electronic Engineering, Soongsil University)
  • Received : 2009.12.30
  • Accepted : 2010.06.10
  • Published : 2010.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the O-mode ultrashort-pulse reflectometry (USPR) millimeter-wave signals that propagate into the plasma and cover a frequency bandwidth of 33-158 GHz are examined numerically using MATLAB. Two important processes are involved in the computation: the propagation of the USPR impulse signal through a waveguide and the frequency up-conversion using millimeter-wave mixers. These mixers are limited to intermediate frequency signals that are less than 500 mV; thus, it is necessary to disperse the impulse signal into a chirped waveform using the waveguide. The stationary phase method is utilized to derive a closed-form formula for a chirped waveform under the assumption that the USPR impulse is Gaussian. In the process of frequency up-conversion, the chirped waveform is mixed with the mixer LO signal, and the lower frequency components of the RF signal are removed using high pass filters.

Keywords

References

  1. C. W. Domier, Y. Roh, and N. C. Luhmann, Jr., “Ultrashort Pulse Reflectometry for Electron Density Profile Measurements”, Rev. Sci. Instrum. Vol. 70, No. 1, pp. 1038-1040, Jan. 1999. https://doi.org/10.1063/1.1149530
  2. Y. Roh, C. W. Domier, and N. C. Luhmann, Jr., “Ultrashort Pulse Reflectometry for Electron Density Profile Measurements on SSPX”, Rev. Sci. Instrum. Vol. 72, No.1, pp. 332-334, Jan. 2001. https://doi.org/10.1063/1.1308999
  3. Y. Roh, C. W. Domier, and N. C. Luhmann, Jr., “Ultrashort Pulse Reflectometry for Density Profile and Fluctuation Measurements on SSPX”, Rev. Sci. Instrum. Vol. 74, No. 3, pp. 1518-1520, March 2003. https://doi.org/10.1063/1.1527254
  4. C. W. Domier, N. C. Luhmann, Jr., Y. Roh, H. S. McLean, E. B. Hooper, and D. N. Hill, “Ultrashort Pulse Reflectometer Performance on Sustained Spheromak Physics Experiment”, Rev. Sci. Instrum. Vol. 75, No. 10, pp. 3868-3670, Oct. 2004. https://doi.org/10.1063/1.1789604
  5. Y. Roh, “Ultrashort Pulse Reflectometry for the Measurement of Electron Density Profiles”, Trans. KIEE Vol.53C, No.1, pp. 8-14, Jan. 2004.
  6. H. S. McLean et al., “Plasma Diagnostics for the Sustained Spheromak Physics Experiment”, Rev. Sci. Instrum. Vol.72, No.1, pp. 556-558, Jan. 2001. https://doi.org/10.1063/1.1318246
  7. P. Stenius and B. York, “On the Propagation of Transients in Waveguides,” IEEE Antennas. Propag. Mag., Vol.37, No.2, pp. 39-44, April 1995. https://doi.org/10.1109/74.382337

Cited by

  1. Reconstruction of the Electron Density Profile in O-mode Ultrashort Pulse Reflectometry using a Two-dimensional Finite Difference Time Domain vol.27, pp.7, 2013, https://doi.org/10.5207/JIEIE.2013.27.7.052
  2. Improvement of Power Spectrum in Ultrashort Pulse Reflectometry Signals Using Three Chirp Configuration vol.28, pp.3, 2014, https://doi.org/10.5207/JIEIE.2014.28.3.051