Quarter‐Wave Plates to Improve Rotational Misalignment Robustness in Medical Telemetry

2021 ◽  
Author(s):  
John Blauert ◽  
Asimina Kiourti
Keyword(s):  
Quarter Wave ◽  
Medical Telemetry

Design and Measurement of a Terahertz Large-Aperture Quarter-Wave Plate with Double-layer Metal Cut Wires on a Flexible and Thin Film

2015 ◽  
Vol 135 (11) ◽  
pp. 478-479
Author(s):  
Takehito Suzuki ◽  
Ryuji Ohuchi ◽  
Nozomu Koja ◽  
Koki Ishihara
Keyword(s):  
Thin Film ◽  
Double Layer ◽  
Quarter Wave Plate ◽  
Wave Plate ◽  
Large Aperture ◽  
Quarter Wave

Geosynchronous orbit and laboratory irradiation of SAS (Silver-Alumina-Silica) quarter-wave thermal control surfaces

1985 ◽  
Author(s):  
D. MOSSMAN ◽  
W. SUTHERLAND ◽  
M. BARSH
Keyword(s):  
Thermal Control ◽  
Geosynchronous Orbit ◽  
Quarter Wave ◽  
Control Surfaces

scholarly journals None sharp corner localized surface plasmons resonance based ultrathin metasurface single layer quarter wave plate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qinyu Qian ◽  
Pengfei Liu ◽  
Li Fan ◽  
Liang Zhao ◽  
Chinhua Wang
Keyword(s):  
Surface Plasmons ◽  
Amplitude Ratio ◽  
Single Layer ◽  
Quarter Wave Plate ◽  
Localized Surface Plasmons ◽  
Sharp Corner ◽  
Wave Plate ◽  
Nanophotonic Devices ◽  
Elliptical Ring ◽  
Quarter Wave

AbstractWe report on a non-sharp-corner quarter wave plate (NCQW) within the single layer of only 8 nm thickness structured by the Ag hollow elliptical ring array, where the strong localized surface plasmons (LSP) resonances are excited. By manipulating the parameters of the hollow elliptical ring, the transmitted amplitude and phase of the two orthogonal components are well controlled. The phase difference of π/2 and amplitude ratio of 1 is realized simultaneously at the wavelength of 834 nm with the transmission of 0.46. The proposed NCQW also works well in an ultrawide wavelength band of 110 nm, which suggests an efficient way of exciting LSP resonances and designing wave plates, and provides a great potential for advanced nanophotonic devices and integrated photonic systems.

Design of CPW-fed Mini Dual-Frequency Implantable Antenna for Medical Telemetry

2020 ◽  
Author(s):  
Yang Feng ◽  
Pan Chen ◽  
Shaopeng Pan ◽  
Dong Cheng ◽  
Gaosheng Li
Keyword(s):  
Dual Frequency ◽  
Implantable Antenna ◽  
Medical Telemetry

scholarly journals Investigation on Wireless Link for Medical Telemetry Including Impedance Matching of Implanted Antennas

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1431
Author(s):  
Ilkyu Kim ◽  
Sun-Gyu Lee ◽  
Yong-Hyun Nam ◽  
Jeong-Hae Lee
Keyword(s):  
Real Time ◽  
Human Body ◽  
Near Field ◽  
Impedance Matching ◽  
The Body ◽  
Field Pattern ◽  
Communication Link ◽  
Far Field ◽  
Antenna Coupling ◽  
Medical Telemetry

The development of biomedical devices benefits patients by offering real-time healthcare. In particular, pacemakers have gained a great deal of attention because they offer opportunities for monitoring the patient’s vitals and biological statics in real time. One of the important factors in realizing real-time body-centric sensing is to establish a robust wireless communication link among the medical devices. In this paper, radio transmission and the optimal characteristics for impedance matching the medical telemetry of an implant are investigated. For radio transmission, an integral coupling formula based on 3D vector far-field patterns was firstly applied to compute the antenna coupling between two antennas placed inside and outside of the body. The formula provides the capability for computing the antenna coupling in the near-field and far-field region. In order to include the effects of human implantation, the far-field pattern was characterized taking into account a sphere enclosing an antenna made of human tissue. Furthermore, the characteristics of impedance matching inside the human body were studied by means of inherent wave impedances of electrical and magnetic dipoles. Here, we demonstrate that the implantation of a magnetic dipole is advantageous because it provides similar impedance characteristics to those of the human body.

High Directivity Quarter-wave Microstrip Coupler with Cancellation Circuit of Wilkinson Divider

2008 ◽  
Author(s):  
Kazuhisa Yamauchi ◽  
Akira Inoue ◽  
Moriyasu Miyazaki
Keyword(s):  
Quarter Wave

scholarly journals High-Contrast and Scattering-Type Transflective Liquid Crystal Displays Based on Polymer-Network Liquid Crystals

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 739 ◽  
Author(s):  
Cheng-Kai Liu ◽  
Wei-Hsuan Chen ◽  
Chung-Yu Li ◽  
Ko-Ting Cheng
Keyword(s):  
Liquid Crystal ◽  
Polymer Network ◽  
Liquid Crystal Displays ◽  
Quarter Wave Plate ◽  
High Contrast ◽  
Trade Off ◽  
Twisted Nematic ◽  
Quarter Wave ◽  
The Common ◽  
Linear Polarizer

The methods to enhance contrast ratios (CRs) in scattering-type transflective liquid crystal displays (ST-TRLCDs) based on polymer-network liquid crystal (PNLC) cells are investigated. Two configurations of ST-TRLCDs are studied and are compared with the common ST-TRLCDs. According to the comparisons, CRs are effectively enhanced by assembling a linear polarizer at the suitable position to achieve better dark states in the transmissive and reflective modes of the reported ST-TRLCDs with the optimized configuration, and its main trade-off is the loss of brightness in the reflective modes. The PNLC cell, which works as an electrically switchable polarizer herein, can be a PN-90° twisted nematic LC (PN-90° TNLC) cell or a homogeneous PNLC (H-PNLC) cell. The optoelectric properties of PN-90° TNLC and those of H-PNLC cells are compared in detail, and the results determine that the ST-TRLCD with the optimized configuration using an H-PNLC cell can achieve the highest CR. Moreover, no quarter-wave plate is used in the ST-TRLCD with the optimized configuration, so a parallax problem caused by QWPs can be solved. Other methods for enhancing the CRs of the ST-TRLCDs are also discussed.

scholarly journals Measurement error caused by quarter-wave plate in the dynamic interferometer: Theory and correction method

2021 ◽  
pp. 127406
Author(s):  
Ronggang Zhu ◽  
Jianjie Zhou ◽  
Bo Li ◽  
Huang Ya
Keyword(s):  
Measurement Error ◽  
Correction Method ◽  
Quarter Wave Plate ◽  
Wave Plate ◽  
Quarter Wave
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