Design of Terahertz SIS Mixers Using Nb/AlN/Nb Junctions Integrated With All-NbTiN Tuning Circuits

Uzawa, Yoshinori; Kroug, M.; Kojima, Takafumi; Makise, Kazumasa; González, Álvaro; Saito, Shingo; Fujii, Yasunori; Kaneko, Keiko; Terai, Hirotaka; Wang, Zhen

doi:10.1109/tasc.2016.2632628

Cited by 11 publications

(5 citation statements)

References 18 publications

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“…Due to the lack of high power and stable radiation sources operating at higher frequency, the mixing technology has received rising popularity for the design of sub-millimeter wave or terahertz system. For example, the harmonic mixers with Schottky Barrier Diodes (SBDs) [9]- [11], Hot Electron Bolometer [12], [13] and Super-conductor Insulator Super-conductor [14], [15] have been extensively applied in the conversion of high frequency to relatively low frequency for the purpose of signal amplification and measurement. Especially when the RF operating…”

Section: Introductionmentioning

confidence: 99%

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Cui

Zhang

et al. 2020

IEEE Access

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For the terahertz harmonic mixer, a design model based on Half-Subdivision and Half-Global Design Method (HS-HGDM) with a single functional unit is proposed. The single functional unit circuit of the mixer, such as LO or IF Low Pass Filter (LPF), is designed by Subdivision Design Method (SDM), and the rest circuits of the mixer are designed by Global Design Method (GDM). The harmonic mixer based on this model is characterized by simple circuit structure, low conversion loss, small circuit size and high stability. In this paper, an improved Compact Suspended Micro-strip Resonators (CSMRs) filter is developed for the IF part of sub-harmonic mixer. The remaining circuits consist of some basic transmission units, such as the High-Z Low-Z impedance Transmission Lines (H-Z L-Z TLs) applied for main circuit, and full/reduced height WR4.3/WR8 applied for providing RF/LO signal. In RF frequency range 200-240 GHz, a Single Sideband (SSB) conversion loss of 7.36±0.76 dB operating at IF frequency 1.8 GHz, and a Double Sideband (DSB) noise temperature below 1034 K with the LO power of 2-5 mW and the LO frequency of 107 GHz were achieved. This broadband sub-harmonic mixer operates at room temperature, which makes it applicable to sub-millimeter wave or terahertz wireless communication systems and imaging inspection systems. INDEX TERMS Terahertz sub-harmonic mixer, CSMRs filter, wireless communication systems.

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Section: Introductionmentioning

confidence: 99%

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Cui

Zhang

et al. 2020

IEEE Access

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“…In principle, an all-Nb tunnel junction can operate up to twice its gap frequency ( f gap ≈ 680 GHz) [9][10][11], but the mixer operation becomes less ideal and the performance starts to deteriorate rapidly at a higher frequency. Furthermore, approaching frequency close to 2 × f gap , a large portion of the photon step would be suppressed, hence limiting the range where an optimal biasing point can be located.…”

Section: Junction and Planar Circuit Technology Considerationsmentioning

confidence: 99%

“…Yassin et al [13] a Karpov et al [12] b Uzawa et al [11] Kojima et al [10] a The report highlighted some fabrication issues when embedding the junction between NbTiN layers, and suggested a thin gold interface layer between the NbTiN and the junction electrode. The authors only reported on the tunnel junction characterisations without full mixer operation.…”

Section: Referencementioning

confidence: 99%

Comparing the performance of 850 GHz integrated bias-tee superconductor-insulator-superconductor (SIS) mixers with single- and parallel-junction tuner

Tan

Rudakov²,

Koshelets

et al. 2022

Supercond. Sci. Technol.

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We present and compare the design and performance of two 850 GHz radial probe fed superconductor-insulator-superconductor mixers, where the antenna is aligned perpendicular to the E-Plane of the input full-height rectangular waveguide connected to a multiple flare-angles smooth-walled horn. Both designs are comprised of 0.5 µm2 hybrid niobium/aluminium-nitride/niobium-nitride tunnel junction, fabricated on top of a niobium titanium nitride ground plane with an Al wiring layer. The entire superconducting circuit is supported with a 40 µm thick quartz substrate. The major difference between the two designs is the method used to cancel out the parasitic junction capacitance for broadband performance. The first design utilises two identical junctions connected in parallel with a short transmission line to convert the capacitance of one junction into the equivalent inductance of the other junction, commonly known as the twin-junction tuning scheme; whilst the second design employs an end-loaded scheme with only one tunnel junction. We found that both methods offer similar radio frequency performances, with close to 2× the double sideband quantum noise temperature, but the twin-junction design is more resilient to fabrication tolerances. However, the end-loaded design offers a much better intermediate frequency (IF) bandwidth performance, made possible by the sub-micron and high current density tunnel junction technology. The improved IF performance is important for many millimetre (mm) and sub-mm observatories, such as future upgrades of Atacama Large Millimetre/sub-mm Array receivers, as well as forthcoming space-borne far-infrared missions. Therefore, we conclude that the single-junction mixer design is the preferred option for THz applications, as long as the fabrication error can be minimised within a certain limit.

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“…Superconductor-insulator-superconductor (SIS) tunnel junctions based on niobium are the main elements of ultrasensitive receivers for radioastronomy [1,2]. The adjusting structures of materials with high limiting frequency, such as NbTiN, are used to increase the operating frequency of the receivers above 700 GHz (the gap frequency of niobium) [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Optimization of fabrication processes for Nb, NbN, NbTiN films and high-quality tunnel junctions for terahertz receiving circuits.

et al. 2022

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This paper describes the optimization of the existing technology for the fabrication of superconducting films and high-quality tunnel junctions on a magnetron sputtering facility. To expand the frequency range to 1.1 THz and to obtain the limiting parameters of superconducting elements, the regimes of production of Nb, NbN, NbTiN films were optimized. These films are used to fabricate superconductor-insulator-superconductor Nb/Al--AlN/NbN tunnel junctions. Al and NbTiN films are required to create receiving elements at frequencies above 700 GHz (the cutoff frequency for niobium); such structures are being developed for the radio astronomy array receiver located in the Atacama Pathfinder Experiment telescope. Keywords: superconductivity, tunnel junctions, magnetron sputtering, thin films.

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Design of Terahertz SIS Mixers Using Nb/AlN/Nb Junctions Integrated With All-NbTiN Tuning Circuits

Cited by 11 publications

References 18 publications

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Comparing the performance of 850 GHz integrated bias-tee superconductor-insulator-superconductor (SIS) mixers with single- and parallel-junction tuner

Optimization of fabrication processes for Nb, NbN, NbTiN films and high-quality tunnel junctions for terahertz receiving circuits.

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