Distributed broad-band frequency translator and its use in a 1-3-GHz coherent reflectometer

Akkaraekthalin, Prayoot; Kee, S.; Weide, Daniel W. van der

doi:10.1109/22.739205

Cited by 14 publications

(4 citation statements)

References 29 publications

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“…This implies that the phase shifter can be used as a frequency translator. To perform in this way, the most important fact is that the phase variation should be a linear function over time to minimize the spurious in the output In that sense, an LH‐NLTL structure exhibits good performance because it is possible to translate frequency with minimized spurious . The phase constant of an LH‐NLTL phase shifter is linearly proportional to its bias voltage:

β true(V true) = \frac{1 + \frac{V_{b i a s}}{V_{b i}}}{ω \sqrt{\frac{L \cdot C_{j 0}}{2}}} \propto V_{b i a s}

where

V_{b i}

is the built‐in diode voltage and

C_{j 0}

is the zero‐bias diode capacitance.…”

Section: Structure Of the Reflectometermentioning

confidence: 99%

“…We applied series‐connected 6‐dB bridged‐T attenuators as a dual directional coupler for the compactness of the proposed system. The structure of the suggested coupler is shown in Figure .…”

Section: Structure Of the Reflectometermentioning

confidence: 99%

“…To overcome the inaccuracy of the system from the low performance of the resistive directional coupler, we employed a four‐port calibration technique . Figure shows the signal flow diagram of the proposed system.…”

Section: Structure Of the Reflectometermentioning

confidence: 99%

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Compact and low-cost reflectometer using a LH-NLTL frequency translator

Park

Kim

2017

Microw. Opt. Technol. Lett.

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In this study, we fabricated a low‐cost, miniaturized reflectometry system using a left‐handed nonlinear transmission line (LH‐NLTL) and compared its performance with that of a commercial vector network analyzer (VNA). In the system, we used the LH‐NLTL as a frequency translator to replace a bulky and expensive frequency synthesizer. In addition, instead of using a bulky broadband coupler, we used a compact resistive coupler to minimize the size of the overall system. To improve system accuracy, we employed a four‐port network calibration equation. The resulting system exhibits highly similar performance compared to a commercial VNA. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:873–876, 2017

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β true(V true) = \frac{1 + \frac{V_{b i a s}}{V_{b i}}}{ω \sqrt{\frac{L \cdot C_{j 0}}{2}}} \propto V_{b i a s}

where

V_{b i}

is the built‐in diode voltage and

C_{j 0}

is the zero‐bias diode capacitance.…”

Section: Structure Of the Reflectometermentioning

confidence: 99%

Section: Structure Of the Reflectometermentioning

confidence: 99%

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Compact and low-cost reflectometer using a LH-NLTL frequency translator

Park

Kim

2017

Microw. Opt. Technol. Lett.

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“…Our use of stable and frequency-offset synthesizers gives a user-selectable beat frequency that is low enough for processing by conventional 100 kHz instrumentation. We have also implemented a frequency offset generator (single-sideband modulator) that can enable the system to be produced using integrated circuits (Akkaraekthalin et al . 1998).…”

Section: Application Of Pulsed Electronic Spectrometermentioning

confidence: 99%

Potential for detection of explosive and biological hazards with electronic terahertz systems

Choi

Bettermann

Weide

2003

Philosophical Transactions of the Royal Society of London. Seri

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The terahertz (THz) regime (0.1-10 THz) is rich with emerging possibilities in sensing, imaging and communications, with unique applications to screening for weapons, explosives and biohazards, imaging of concealed objects, water content and skin. Here we present initial surveys to evaluate the possibility of sensing plastic explosives and bacterial spores using field-deployable electronic THz techniques based on short-pulse generation and coherent detection using nonlinear transmission lines and diode sampling bridges. We also review the barriers and approaches to achieving greater sensing-at-a-distance (stand-off) capabilities for THz sensing systems. We have made several reflection measurements of metallic and non-metallic targets in our laboratory, and have observed high contrast relative to reflection from skin. In particular, we have taken small quantities of energetic materials such as plastic explosives and a variety of Bacillus spores, and measured them in transmission and in reflection using a broadband pulsed electronic THz reflectometer. The pattern of reflection versus frequency gives rise to signatures that are remarkably specific to the composition of the target, even though the target's morphology and position is varied. Although more work needs to be done to reduce the effects of standing waves through time-gating or attenuators, the possibility of mapping out this contrast for imaging and detection is very attractive.

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Electronic Sources and Detectors for Wideband Sensing in the Terahertz Regime

Weide¹

2003

Springer Series in Optical Sciences

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Distributed broad-band frequency translator and its use in a 1-3-GHz coherent reflectometer

Cited by 14 publications

References 29 publications

Compact and low-cost reflectometer using a LH-NLTL frequency translator

Compact and low-cost reflectometer using a LH-NLTL frequency translator

Potential for detection of explosive and biological hazards with electronic terahertz systems

Electronic Sources and Detectors for Wideband Sensing in the Terahertz Regime

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