Optimization of Josephson oscillators requires a quantitative understanding of their microwave properties. A Josephson junction has a geometry similar to a microstrip patch antenna. However, it is biased by a dc current distributed over the whole area of the junction. The oscillating electric field is generated internally via the ac-Josephson effect. In this work, I present a distributed, active patch antenna model of a Josephson oscillator. It takes into account the internal Josephson electrodynamics and allows for the determination of the effective input resistance, which couples the Josephson current to cavity modes in the transmission line formed by the junction. The model provides full characterization of Josephson oscillators and explains the origin of the low radiative power efficiency. Finally, I discuss the design of an optimized Josephson patch oscillator capable of reaching high efficiency and radiation power for emission into free space.
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http://dx.doi.org/10.3762/bjnano.14.16 | DOI Listing |
Sci Rep
January 2025
Department of Electronic Engineering, Hanyang University, Seoul, 04763, South Korea.
This paper presents novel MIMO microstrip patch antennas with dimensions of 40 × 80 × 1.6 mm³ incorporating a decoupling and pattern correction structure (DPCS) designed to mitigate mutual coupling and radiation pattern distortion, operating within 3.6-3.
View Article and Find Full Text PDF3D Print Addit Manuf
December 2024
Escuela de Ingeniería Eléctrica, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
This article presents a high-frequency characterization from 1 up to 10 GHz of electroplated conductive filaments in 3D printed microwave topologies. This study implements different microstrip lines and antennas to compare their performance as-is and with the electroplating process. The results for the microstrip lines show a significant decrease in losses for the electroplated devices, even reaching loss levels of pure copper devices.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China.
A microwave dielectric ceramic based on lithium aluminum silicate (LiAlSiO) with ultralow permittivity was synthesized using the traditional solid-state reaction technique, and its dielectric characteristics at microwave frequencies are presented. The nominal LiAlSiO ceramic exhibited a relative permittivity of 3.95.
View Article and Find Full Text PDFSensors (Basel)
November 2024
School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China.
Miniature patch antenna sensors have great potential in the field of structural health monitoring for crack propagation detection due to their small size and high sensitivity. A primary research focus has been achieving efficient miniaturization, with the performance of the dielectric layer playing a pivotal role. Studies have demonstrated that increasing the relative dielectric constant (ε) of the dielectric layer can reduce antenna size, but higher dielectric losses (tanδ) can lower radiation efficiency.
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November 2024
Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada.
The rise of CubeSats has unlocked opportunities for cutting-edge space missions with reduced costs and accelerated development timelines. CubeSats necessitate a high-gain antenna that can fit within a tightly confined space. This paper is primarily concerned with designing a compact Ku-band offset cylindrical reflector antenna for a CubeSat-based Earth Observation mission, with the goal of monitoring Arctic snow and sea ice.
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