Wideband waveform distortion and compensation techniques

Belcher, M.L.; Howard, Robert; Mitchell, Mark A.

doi:10.1109/ntc.1991.147998

Cited by 6 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, represents the filter coefficient and represents the convolution function. Finally, the compensation function is given by (3) where represents the filter frequency response and is the distorted DAC output frequency response. In (2), the linear error, , represents the phase offset and it can be corrected by internal calibration.…”

Section: System Predistortion Coefficient Characterizationmentioning

confidence: 99%

“…1 diagram of a wideband LFM waveform system with a baseband waveform generator and predistortion coefficients extraction module. Generally, system errors originate from imbalances, the intermediate frequency and radio frequency filter's group delay, the digital-to-analog converter's (DAC's) sample and hold characteristics, high speed local oscillation (LO) band selection switching time, and other nonlinear effects [3], [4].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Wideband Linear Frequency Modulated Waveform Compensation Using System Predistortion and Phase Coefficients Extraction Method

Kim

Myung

2007

IEEE Microw. Wireless Compon. Lett.

View full text Add to dashboard Cite

This letter presents an effective method to compensate for the wideband linear frequency modulated waveform errors using system predistortion coefficients. The coefficients can be readily extracted by measuring and analyzing the changing rates of the period of non-constant beat frequencies generated from a nonlinear system in the time domain. The amplitude distortion components are examined using the polynomial curve-fitting method. In order to experimentally validate the practical feasibility of the waveform generator and the predistortion coefficients extraction module, the waveform's amplitude ripple, range resolution, and peak sidelobe ratios are measured and analyzed. The measured amplitude ripple at 5.3 GHz is improved from 1.835 to 0.333 dB and from 2.793 to 0.75 dB within 50 and 85 MHz bandwidth, respectively. Finally, the range resolution is improved from 4.102 to 3.103 m for 50 MHz bandwidth and the peak sidelobe ratio is improved from 7.78 to 20.55 dB for 85 MHz bandwidth with the applied predistortion.Index Terms-Frequency linearity, linear frequency modulated (LFM) waveform compensation, memory map, peak sidelobe ratio (PSR), predistortion coefficient, range resolution.

show abstract

Section: System Predistortion Coefficient Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Wideband Linear Frequency Modulated Waveform Compensation Using System Predistortion and Phase Coefficients Extraction Method

Kim

Myung

2007

IEEE Microw. Wireless Compon. Lett.

View full text Add to dashboard Cite

show abstract

“…A wideband chirp signal is necessary for obtaining high‐resolution images in a synthetic aperture radar (SAR). There are many waveform generation methods for synthesizing a wideband chirp signal: frequency multiplication SAW filtering, memory mapping, and direct digital synthesis . In particular, a bandwidth expansion technique using frequency multiplication and memory mapping is generally used in advanced space‐borne SAR systems such as TerraSAR‐X, Cosmo‐skymed, and RADARSAT 2 .…”

Section: Introductionmentioning

confidence: 99%

Analysis on spectral regrowth of chirp bandwidth expansion technique in high‐resolution SAR system

Kim

Sung

2013

Micro & Optical Tech Letters

View full text Add to dashboard Cite

This article presents an analysis of the root causes of the spectral regrowth due to the higher‐order intermodulation in a chirp bandwidth expansion scheme using a single‐sideband modulator and frequency multipliers. The spectral regrowth of synthetic aperture radar waveform was reduced by minimizing the gain and phase imbalances between the I and the Q channels. Further, the gain and phase imbalance requirements were defined on the basis of the evaluation of the impulse response function. The 150‐MHz bandwidth of a chirp signal at 2.4 GHz was expanded to 600 MHz at 9.6 GHz. By adjusting the dc offset and the gain imbalance between the I and the Q channels, the carrier level was reduced from −28.7 to −53.4 dBm and the sidelobe levels caused by the spectral regrowth were reduced by approximately 8–9 dB. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:400–404, 2014

show abstract

Wideband Phased Arrays Distortion of Short Pulses

Rotman

Israel²,

Green³

2005 IEEE Antennas and Propagation Society International Symposium

View full text Add to dashboard Cite

Wideband waveform distortion and compensation techniques

Cited by 6 publications

References 4 publications

Wideband Linear Frequency Modulated Waveform Compensation Using System Predistortion and Phase Coefficients Extraction Method

Wideband Linear Frequency Modulated Waveform Compensation Using System Predistortion and Phase Coefficients Extraction Method

Analysis on spectral regrowth of chirp bandwidth expansion technique in high‐resolution SAR system

Wideband Phased Arrays Distortion of Short Pulses

Contact Info

Product

Resources

About