Transmission Loss in Coplanar Waveguide and Planar Goubau Line between 0.75 THz and 1.1 THz

Cabello-Sanchez, Juan; Rodilla, Helena; Drakinskiy, Vladimir; Stake, Jan

doi:10.1109/irmmw-thz.2018.8510326

“…The CPW was designed to suit both the measurement probe's pitch (25 µm) and characteristic impedance (50 Ω) [22], yielding a central strip width of 23.5 µm and a ground separation of 1.5 µm. The CPW was designed on a ultra-thin 23 µm thick polyethylene terephthalate (PET) film substrate ( ′ = 3.15 and tan( ) = 0.017 at 1 THz [24]), to avoid power leakage [25] to undesirable substrate modes [26]. The CPWs and their dedicated calibration standards were fabricated using e-beam lithography and evaporation of 20 nm Ti and 350 nm Au on top of the PET substrate.…”

Section: Methodsmentioning

confidence: 99%

On-Chip Characterization of High-Loss Liquids Between 750 and 1100 GHz

Cabello-Sanchez

¹

,

Drakinskiy

²

,

Stake

³

et al. 2021

IEEE Trans. THz Sci. Technol.

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Terahertz spectroscopy is a promising tool for analyzing the picosecond dynamics of biomolecules, which is influenced by surrounding water molecules. However, water causes extreme losses to terahertz signals, preventing sensitive measurements at this frequency range. Here, we present sensitive on-chip terahertz spectroscopy of highly lossy aqueous solutions using a vector network analyzer, contact probes, and a coplanar waveguide with a 0.1 mm wide microfluidic channel. The complex permittivities of various deionized water/isopropyl alcohol concentration are extracted from a known reference measurement across the frequency range 750-1100 GHz and agrees well with literature data. The results prove the presented method as a highsensitive approach for on-chip terahertz spectroscopy of high-loss liquids, capable of resolving the permittivity of water.

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“…The CPW was designed to suit both the measurement probe's pitch (25 µm) and characteristic impedance (50 Ω) [22], yielding a central strip width of 23.5 µm and a ground separation of 1.5 µm. The CPW was designed on a ultra-thin 23 µm thick polyethylene terephthalate (PET) film substrate ( = 3.15 and tan(δ) = 0.017 at 1 THz [24]), to avoid power leakage [25] to undesirable substrate modes [26]. The CPWs and their dedicated calibration standards were fabricated using e-beam lithography and evaporation of 20 nm Ti and 350 nm Au on top of the PET substrate.…”

Section: Methodsmentioning

confidence: 99%

On-Chip Characterization of High-Loss Liquids between 750 GHz and 1100 GHz

Cabello-Sánchez,

Drakinskiy,

Stake

et al. 2020

Preprint

0

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Terahertz spectroscopy is a promising tool for analyzing the picosecond dynamics of biomolecules, which is influenced by surrounding water molecules. However, water causes extreme losses to terahertz signals, preventing sensitive measurements at this frequency range. Here, we present sensitive on-chip terahertz spectroscopy of highly lossy aqueous solutions using a vector network analyzer, contact probes, and a coplanar waveguide with a 0.1 mm wide microfluidic channel. The complex permittivities of various deionized water/isopropyl alcohol concentration are extracted from a known reference measurement across the frequency range 750-1100 GHz and agrees well with literature data. The results prove the presented method as a highsensitive approach for on-chip terahertz spectroscopy of high-loss liquids, capable of resolving the permittivity of water.

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“…Its propagation conditions depend on the electrical thickness of its substrate [16], where electrically-thin substrates minimize losses and dispersion. The PGL has shown to have one of the highest power efficiencies for metal planar waveguides [17], thus being a good candidate for circuit design at THz frequencies.…”

Section: Introductionmentioning

confidence: 99%

Capacitively-coupled resonators for terahertz planar-Goubau-line filters

Cabello-Sanchez¹,

Drakinskiy²,

Stake³

et al. 2022

Preprint

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Low-loss planar Goubau lines show promising potential for terahertz applications. However, a single-wire waveguide exhibits less design freedom than standard multi-conductor lines, which is a significant constraint for realizing standard components. Existing filters for planar Goubau line lack clear design procedures preventing the synthesis of an arbitrary filter response. In this work, we present a design for a bandpass/bandstop filter for planar Goubau line by periodically loading the line with capacitively coupled ∕2 resonators, which can be easily tuned by changing their electrical length. The filter's working principle is explained by a proposed transmission-line model. We designed and fabricated a passband filter centered at 0.9 THz on a 10-m silicon-membrane substrate and compared measurement results between 0.5 THz and 1.1 THz to electromagnetic simulations, showing excellent agreement in both 11 and 21 . The measured passband has an insertion loss of 7 dB and a 3-dB bandwidth of 31%. Overall, the proposed filter design has good performance while having a simple design procedure.

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Transmission Loss in Coplanar Waveguide and Planar Goubau Line between 0.75 THz and 1.1 THz

Cited by 12 publications

References 11 publications

On-Chip Characterization of High-Loss Liquids Between 750 and 1100 GHz

On-Chip Characterization of High-Loss Liquids Between 750 and 1100 GHz

On-Chip Characterization of High-Loss Liquids between 750 GHz and 1100 GHz

Capacitively-coupled resonators for terahertz planar-Goubau-line filters

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