scholarly journals First demonstration and performance of an injection locked continuous wave magnetron to phase control a superconducting cavity

2011 ◽  
Vol 14 (3) ◽  
Author(s):  
A. C. Dexter ◽  
G. Burt ◽  
R. G. Carter ◽  
I. Tahir ◽  
H. Wang ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Phase Control ◽  
Superconducting Cavity ◽  
And Performance

scholarly journals Electrically Tunable Hydrogen-Bonded Liquid Crystal Phase Control Device

2018 ◽  
Vol 8 (12) ◽  
pp. 2478 ◽  
Author(s):  
Ryota Ito ◽  
Michinori Honma ◽  
Toshiaki Nose
Keyword(s):  
Liquid Crystal ◽  
Phase Shifter ◽  
Continuous Wave ◽  
Phase Control ◽  
Terahertz Wave ◽  
Control Device ◽  
Absorption Properties ◽  
Control Devices ◽  
Wave Control ◽  
Hydrogen Bonded

Terahertz waves have attracted much attention mainly because of their potential in imaging, security checking, nondestructive testing, and information and communication technologies. In the past few years, there has been an extensive effort to investigate terahertz wave control devices. Liquid crystal (LC) devices are strong candidates for high-performance terahertz wave control devices because of their controllability at low drive voltages and their low power consumption. In this study, we fabricated an electrically tunable phase control device by using a hydrogen-bonded LC material. We investigated the performance of the LC phase shifter by using a far infrared continuous wave laser. We also estimated the birefringence and absorption properties of the hydrogen-bonded LC at 2.5 THz by using Jones matrix calculations. The measurements and calculation results indicated that the hydrogen-bonded LC showed no dichroism at 2.5 THz. Based on the absorption properties, we believe that it could be a strong candidate for use in future terahertz devices.

Continuous-wave terahertz system with electro-optical terahertz phase control

2008 ◽  
Vol 44 (14) ◽  
pp. 863 ◽  
Author(s):  
T. Göbel ◽  
D. Schoenherr ◽  
C. Sydlo ◽  
M. Feiginov ◽  
P. Meissner ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Phase Control ◽  
Continuous Wave Terahertz System

scholarly journals Bow-Tie Cavity for Terahertz Radiation

Photonics ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Luigi Consolino ◽  
Annamaria Campa ◽  
Davide Mazzotti ◽  
Miriam Vitiello ◽  
Paolo De Natale ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Resonant Cavity ◽  
Thz Radiation ◽  
Wire Grid ◽  
Quantum Cascade ◽  
Spherical Mirrors ◽  
And Performance ◽  
Quality Factor Q ◽  
Wire Grid Polarizer ◽  
Bow Tie

We report on the development, testing, and performance analysis of a bow-tie resonant cavity for terahertz (THz) radiation, injected with a continuous-wave 2.55 THz quantum cascade laser. The bow-tie cavity employs a wire-grid polarizer as input/output coupler and a pair of copper spherical mirrors coated with an unprotected 500 nm thick gold layer. The improvements with respect to previous setups have led to a measured finesse value F = 123, and a quality factor Q = 5.1·105. The resonator performances and the relevant parameters are theoretically predicted and discussed, and a comparison among simulated and experimental spectra is given.

scholarly journals High-Efficiency Super-Resolution FMCW Radar Algorithm Based on FFT Estimation

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4018
Author(s):  
Bong-seok Kim ◽  
Youngseok Jin ◽  
Jonghun Lee ◽  
Sangdong Kim
Keyword(s):  
High Efficiency ◽  
Continuous Wave ◽  
Super Resolution ◽  
Music Algorithm ◽  
Multiple Signal Classification ◽  
Fmcw Radar ◽  
Similar Performance ◽  
Average Complexity ◽  
Resolution Algorithm ◽  
And Performance

This paper proposes a high-efficiency super-resolution frequency-modulated continuous-wave (FMCW) radar algorithm based on estimation by fast Fourier transform (FFT). In FMCW radar systems, the maximum number of samples is generally determined by the maximum detectable distance. However, targets are often closer than the maximum detectable distance. In this case, even if the number of samples is reduced, the ranges of targets can be estimated without degrading the performance. Based on this property, the proposed algorithm adaptively selects the number of samples used as input to the super-resolution algorithm depends on the coarsely estimated ranges of targets using the FFT. The proposed algorithm employs the reduced samples by the estimated distance by FFT as input to the super resolution algorithm instead of the maximum number of samples set by the maximum detectable distance. By doing so, the proposed algorithm achieves the similar performance of the conventional multiple signal classification algorithm (MUSIC), which is a representative of the super resolution algorithms while the performance does not degrade. Simulation results demonstrate the feasibility and performance improvement provided by the proposed algorithm; that is, the proposed algorithm achieves average complexity reduction of 88% compared to the conventional MUSIC algorithm while achieving its similar performance. Moreover, the improvement provided by the proposed algorithm was verified in practical conditions, as evidenced by our experimental results.

scholarly journals Implementation and evaluation of coherent synthetic aperture radar processing for level measurements of bulk goods with an FMCW-system

2010 ◽  
Vol 8 ◽  
pp. 7-11 ◽  
Author(s):  
M. Vogt ◽  
M. Gerding ◽  
T. Musch
Keyword(s):  
Synthetic Aperture Radar ◽  
Continuous Wave ◽  
Industrial Process ◽  
Radar System ◽  
Synthetic Aperture ◽  
Fmcw Radar ◽  
Spatially Resolved ◽  
Single Antenna ◽  
And Performance ◽  
Aperture Radar

Abstract. In industrial process measurement instrumentation, radar systems are well established for the measurement of filling levels of liquids in tanks. Level measurements of bulk goods in silos, on the other hand, are more challenging because the material is heaped up and its surface has typically a relatively complex shape. In this paper, the application of synthetic aperture radar (SAR) reconstruction with a frequency modulated continuous wave (FMCW) radar system for level measurements of bulk goods is evaluated. In the proposed monostatic setup, echo signals are acquired at discrete antenna positions on top of the silo. Spatially resolved information about the surface contour of a bulk good heap is reconstructed by coherent 'delay and sum' processing. The concept has been experimentally evaluated with a 24 to 26 GHz FMCW radar system mounted on a linear stepping motor positioning unit. Measurements on a thin metal wire at different range and on a curved test-object with a diffusely scattering surface have been performed to analyze the system's point spread function (PSF) and performance. Constant range and azimuth resolutions (−6 dB) of 15 cm and 8 cm, respectively, have been obtained up to a range of 6 m, and results of further evaluations show that the proposed concept allows more accurate and reliable level reconstructions of surface profiles compared to the conventional approach with measurements at a single antenna position.

A high-resolution Raman gain spectrometer for spectral lineshape studies

1991 ◽  
Vol 69 (5) ◽  
pp. 558-563 ◽  
Author(s):  
J. W. Forsman ◽  
P. M. Sinclair ◽  
P. Duggan ◽  
J. R. Drummond ◽  
A. D. May
Keyword(s):  
High Resolution ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Integration Time ◽  
Raman Gain ◽  
Spectral Lineshape ◽  
Spectral Profiles ◽  
And Performance

The details and performance of a shot-noise-limited high-resolution (≤ 2 MHz) Raman gain spectrometer are discussed and compared to a "standard" continuous wave (cw) spectrometer. For a single pass cell and 1 s integration time, a signal-to-noise ratio greater than 1000 is obtained for the Q(2) line of D2 at pressures above a few atmospheres. The quality of the spectrometer for the determination of spectral profiles is demonstrated by examining the Dicke narrowing of the line.

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