Determination of Sweep Linearity Requirements in FMCW Radar Systems Based on Simple Voltage-Controlled Oscillator Sources

Brennan, Paul V.; Huang, Yanchuan; Ash, Matthew; Chetty, Kevin

doi:10.1109/taes.2011.5937252

Cited by 59 publications

(23 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resolution of the signal generator is 12 bits which for the maximum bandwidth of 4 GHz leads to an unambiguous range of over 100 m (where the behavior is FMCW type). The RF VCO block is a low-cost X-band VCO with 15% linearity (defined as the ratio between the maximum frequency deviation of the characteristic from linear and the total sweep bandwidth [18], [19]) which provides the local oscillator (LO) signal. The high nonlinearity of this VCO can be software corrected and is no need of an expensive YIG-based VCO.…”

Section: Short-range Fmcw Radar Architecturementioning

confidence: 99%

See 1 more Smart Citation

Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements

Anghel¹,

Vasile

Cacoveanu

et al. 2014

IEEE Trans. Geosci. Remote Sensing

118

View full text Add to dashboard Cite

Abstract-The frequency modulated continuous wave (FMCW) radar is an alternative to the pulse radar when the distance to the target is short. Typical FMCW radar implementations have a homodyne architecture transceiver which limits the performances for short-range applications: the beat frequency can be relatively small and placed in the frequency range affected by the specific homodyne issues (DC offset, self-mixing and 1/f noise). Additionally, one classical problem of a FMCW radar is that the voltage controlled oscillator adds a certain degree of nonlinearity which can cause a dramatic resolution degradation for wideband sweeps. This paper proposes a short-range X-band FMCW radar platform which solves these two problems by using a heterodyne transceiver and a wideband nonlinearity correction algorithm based on high-order ambiguity functions and time resampling. The platform's displacement measurement capability was tested on range profiles and synthetic aperture radar (SAR) images acquired for various targets. The displacements were computed from the interferometric phase and the measurement errors were situated below 0.1 mm for metal bar targets placed at a few meters from the radar.

show abstract

Section: Short-range Fmcw Radar Architecturementioning

confidence: 99%

“…The slope of the frequency-voltage characteristic for some radio frequency VCOs may be reasonably approximated by a quadratic curve [19]. However, a more general approach is to assume a polynomial frequency-voltage dependence.…”

Section: Nonlinearity Correction Algorithmmentioning

confidence: 99%

Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements

Anghel¹,

Vasile

Cacoveanu

et al. 2014

IEEE Trans. Geosci. Remote Sensing

118

View full text Add to dashboard Cite

show abstract

“…The slope of the frequency-voltage characteristic for some radio frequency VCOs may be reasonably approximated by a quadratic curve [11]. However, a more general approach is to assume a polynomial frequency-voltage dependence.…”

Section: Nonlinearity Correction Algorithm a Nonlinear Fmcw Signmentioning

confidence: 99%

FMCW transceiver wideband sweep nonlinearity software correction

Anghel¹,

Vasile

Cacoveanu

et al. 2013

2013 IEEE Radar Conference (RadarCon13)

View full text Add to dashboard Cite

Abstract-This paper presents a novel wideband sweep nonlinearity software correction method for a frequency modulated continuous wave (FMCW) transceiver based on the high-order ambiguity function (HAF) and time resampling. By emphasizing the polynomial-phase nature of the FMCW signal, it is shown that the HAF processing algorithm is well suited for estimating the sweep nonlinearity coefficients. The estimated coefficients are used to build a correction function which is applied by resampling the beat signal on each sweep interval. The sweep nonlinearity correction procedure is validated on real data acquired with a low-cost X-band T/R module.

show abstract

“…Among its various characteristics, the linearity of the VCO's output frequency tuning is a critical figure-of-merit in most applications. For example, the linearity of the output frequency sweep is directly connected to the range accuracy of the frequency modulation continuous wave (FMCW) radar system [1]. In phase-locked loop circuits, it is known that the nonlinear frequency tuning characteristic in a VCO is one of the main sources affecting phase noise degradation [2].…”

Section: Introductionmentioning

confidence: 99%

“…First, we sought the kind of C-V response characteristic necessary to achieve the linear frequency tuning. Then a MEMS varactor satisfying the required C-V response characteristic was designed and fabricated using Open Access *Correspondence: jbyoon@kaist.ac.kr 1 School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea Full list of author information is available at the end of the article surface micromachining. At this step, the core concept for this kind of varactor was adopted from the previous paper [13].…”

Section: Introductionmentioning

confidence: 99%

Linear frequency tuning in an LC-resonant system using a C–V response controllable MEMS varactor

Han

Yoon

et al. 2017

Micro and Nano Syst Lett

View full text Add to dashboard Cite

This paper proposes a device level solution to achieve linear frequency tuning with respect to a tuning voltage (V tune ) sweep in an inductor (L)-capacitor (C) resonant system. Since the linearity of the resonant frequency vs. tuning voltage (f-V) relationship in an LC-resonant system is closely related to the C-V response characteristic of the varactor, we propose a C-V response tunable varactor to realize the linear frequency tuning. The proposed varactor was fabricated using microelectromechanical system (MEMS) surface micromachining. The fabricated MEMS varactor has the ability to dynamically change the C-V response characteristic according to a curve control voltage (V curve-control ). When V curvecontrol was increased from zero to 9 V, the C-V response curve was changed from a linear to a concave form (i.e., the capacitance decreased quickly in the low tuning voltage region and slowly in the high tuning voltage region). This change in the C-V response characteristic resulted in a change in the f-V relationship, and we successfully demonstrated almost perfectly linear frequency tuning in the LC-resonant system, with a linearity factor of 99.95%.

show abstract

Determination of Sweep Linearity Requirements in FMCW Radar Systems Based on Simple Voltage-Controlled Oscillator Sources

Cited by 59 publications

References 8 publications

Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements

Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements

FMCW transceiver wideband sweep nonlinearity software correction

Linear frequency tuning in an LC-resonant system using a C–V response controllable MEMS varactor

Contact Info

Product

Resources

About