arXiv subjects

Vladimir Drakinskiy

Publications and source records attributed to Vladimir Drakinskiy.

8 recordsLinked to original sources

arXiv2026

Broadband 600- and 1200-GHz Subharmonically Pumped Schottky Diode Mixers

A subharmonic mixer topology is introduced that uses quarter-wave stubs to create virtual RF/LO grounds and provide impedance matching in close proximity to the antiparallel Schottky barrier diode pair, thereby reducing the electrical length and enabling broadband operation. The RF/LO matching topology is demonstrated at 600 GHz and 1200 GHz, with good agreement between measured and simulated performance. The 600-GHz mixer demonstrates approximately 20% RF bandwidth with a DSB receiver noise temperature below 1300 K across most of the measured band, while the 1200-GHz implementation achieves DSB receiver noise temperatures below 3000 K over a broad frequency range. Both mixers are characterized at room temperature with approximately 2 mW of LO power. The 600-GHz mixer is used in the Submillimeter Wave Instrument (SWI) onboard ESA's Jupiter Icy Moons Explorer. Overall, these results demonstrate state-of-the-art room-temperature performance for broadband receiver front ends targeting atmospheric research and remote-sensing applications.

physics.ins-det↗

arXiv2026

Compact Dual-Polarization Schottky Barrier Diode Receivers for Submillimeter Wave Remote Sensing

Dual-polarization heterodyne receivers operating at 325 GHz, 424 GHz, and 650 GHz at room temperature are presented. Polarimetric measurements are enabled by two orthogonal open-ended E-field probes, co-optimized and integrated with two subharmonic GaAs Schottky-barrier diode mixers. The down-converted signals (IF) are amplified using low-noise InP HEMT amplifiers integrated into the receiver module, along with IF matching networks, dc-bias boards, a shared local oscillator (LO) distribution network, and a single smooth-walled, conical, spline-horn antenna. Maximum cross-polarization isolation of 25 dB, 34 dB, and 25 dB was achieved at 315 GHz, 421 GHz, and 650 GHz, respectively. The measured double-sideband (DSB) receiver noise temperatures are 833 K, 835 K, and 1623 K at 315 GHz, 421 GHz, and 630 GHz, respectively. Stability measurements, with an integration Allan time of more than 10 s, were obtained for all receivers. Overall, the integrated dualpolarization receiver topology achieves excellent sensitivity in a highly compact package, offering an efficient and scalable solution for polarimetric applications in submillimeter-wave remote sensing

physics.ins-det↗

arXiv2023

A corrugated planar-Goubau-line termination for terahertz waves

The planar Goubau line is a promising low-loss metal waveguide for terahertz interconnects. To enable advanced system architectures and multi-port measurements based on planar Goubau lines, there is a strong need for broadband impedance-matched loads, which can be used to absorb the energy and minimize standing waves in a system. In this work, we propose a matched load for planar Goubau lines based on an exponentially-tapered corrugated line, gradually increasing conductor losses while maintaining small reflections. The corrugation density is high enough to increase conductor losses without requiring an auxiliary low-conductivity material, simplifying the fabrication process. A 400-$μ$m long planar Goubau line load was fabricated on a 10-$μ$m thick silicon substrate suspended in the air. Electromagnetic simulations of the load show excellent agreement with calibrated reflection measurements in the frequency range 0.5 THz - 1.1 THz. Above the cut-off frequency of around 580 GHz, the measured reflections are much less than -19 dB, below the noise floor of the characterization setup.

physics.app-ph↗

arXiv2022

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

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 λ/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-μm silicon-membrane substrate and compared measurement results between 0.5 THz and 1.1 THz to electromagnetic simulations, showing excellent agreement in both S11 and S21. 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.

physics.app-ph↗

arXiv2021

A 3.5-THz, x6-Harmonic, Single-Ended Schottky Diode Mixer for Frequency Stabilization of Quantum-Cascade Lasers

Efficient and compact frequency converters are essential for frequency stabilization of terahertz sources. In this paper, we present a 3.5-THz, x6-harmonic, integrated Schottky diode mixer operating at room temperature. The designed frequency converter is based on a single-ended, planar Schottky diode with a sub-micron anode contact area defined on a suspended 2-$μ$m ultra-thin GaAs substrate. The dc-grounded anode pad was combined with the radio frequency E-plane probe, which resulted in an electrically compact circuit. At 200 MHz intermediate frequency, a mixer conversion loss of about 59 dB is measured and resulting in a 40 dB signal-to-noise ratio for phase locking 3.5-THz quantum-cascade laser. Using a quasi-static diode model combined with electromagnetic simulations, good agreement with the measured results was obtained. Harmonic frequency converters without the need of cryogenic cooling will help in the realization of highly sensitive space and air-borne heterodyne receivers.

physics.ins-det↗

arXiv2020

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

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 high-sensitive approach for on-chip terahertz spectroscopy of high-loss liquids, capable of resolving the permittivity of water.

physics.app-ph↗

arXiv2020

IR- and visible- light single photon detection in superconducting $MgB_{2}$ nanowires

State-of-the-art Superconducting Nanowire Single Photon Detectors based on low-Tc materials reach 100% quantum efficiency. However, the response time is limited to >1-10 ns. Recently, it has been shown that due to a much lower kinetic inductance, a 100 ps response rate can be achieved in 120 $μ$m-long $MgB_{2}$ nanowires. In this work, we demonstrate experimentally that such $MgB_{2}$ nanowires function as single-photon detectors for both visible ($λ$= 630 nm) and infrared ($λ$= 1550 nm) photons when biased close to the critical current, with a dark count rate of <10 cps. $MgB_{2}$ photodetectors over-perform NbN SNSPDs in speed by at least an order of magnitude for similar nanowire lengths. Such photodetectors offer a platform for single-photon detectors with a long thought-after combination of a large detector area and a response rate of up to 10 GHz with a single readout line.

physics.app-ph↗

arXiv2020

Low kinetic inductance superconducting $MgB_{2}$ nanowire photon detectors with a 100 picosecond relaxation time

Properties of superconducting nanowires set the performance level for Superconducting Nanowire Single Photon Detectors (SNSPD). Reset time in commonly employed large area SNSPDs,5-10ns,is known to be limited by the nanowires kinetic inductance.On the other hand, reduction of the kinetic inductance in small area (waveguide integrated) SNSPDs prevents biasing them close to the critical current due to latching into a permanent resistive state.In order to reduce the reset time in SNSPDs, superconducting nanowires with both low kinetic inductance and fast electron energy relaxation are required. In this paper, we report on narrow (15-100nm) and long (up to 120 $μ$m) superconducting $MgB_{2}$ nanowires offering such combination of properties.In 5 nm-thick $MgB_{2}$ films, grown using Hybrid Physical Chemical Vapor Deposition, the electron relaxation time was 12ps, the critical temperature was 32K, and the critical current density was 5x$10^{7}$ A/$cm^{2}$ (at 4.8K). Using microwave reflectometry, we measured a kinetic inductance of Lk0(4.8K)=1.3-1.6 pH/sqr regardless of the nanowire width, which results in a magnetic field penetration depth of 90 nm. These values are very close to those in pristine $MgB_{2}$. For 120 $μ$m long nanowires the response time was only 100ps, i.e. 1/80 of that in previously reported NbN nanowire photon detectors of similar dimensions.

cond-mat.supr-con↗