There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

We show that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu//sub eff/, which can be tuned to values not accessible in naturally occurring materials, including large imaginary components of /spl mu//sub eff/. The microstructure is on a scale much less than the wavelength of radiation, is not resolved by incident microwaves, and uses a very low density of metal so that structures can be extremely lightweight. Most of the structures are resonant due to internal capacitance and inductance, and resonant enhancement combined with compression of electrical energy into a very small volume greatly enhances the energy density at critical locations in the structure, easily by factors of a million and possibly by much more. Weakly nonlinear materials placed at these critical locations will show greatly enhanced effects raising the possibility of manufacturing active structures whose properties can be switched at will between many states.

/pdf/magnetism-from-conductors-and-enhanced-nonlinear-phenomena-2fpnoamwae.pdf

Magnetism from conductors and enhanced nonlinear phenomena

Preface to the Second Edition. Preface to the First Edition. 1 Introduction. 2 Network Analysis. 2.1 Network Variables. 2.2 Scattering Parameters. 2.3 Short-Circuit Admittance Parameters. 2.4 Open-Circuit Impedance Parameters. 2.5 ABCD Parameters. 2.6 Transmission-Line Networks. 2.7 Network Connections. 2.8 Network Parameter Conversions. 2.9 Symmetrical Network Analysis. 2.10 Multiport Networks. 2.11 Equivalent and Dual Network. 2.12 Multimode Networks. 3 Basic Concepts and Theories of Filters. 3.1 Transfer Functions. 3.2 Lowpass Prototype Filters and Elements. 3.3 Frequency and Element Transformations. 3.4 Immittance Inverters. 3.5 Richards' Transformation and Kuroda Identities. 3.6 Dissipation and Unloaded Quality Factor. 4 Transmission Lines and Components. 4.1 Microstrip Lines. 4.2 Coupled Lines. 4.3 Discontinuities and Components. 4.4 Other Types of Microstrip Lines. 4.5 Coplanar Waveguide (CPW). 4.6 Slotlines. 5 Lowpass and Bandpass Filters. 5.1 Lowpass Filters. 5.2 Bandpass Filters. 6 Highpass and Bandstop Filters. 6.1 Highpass Filters. 6.2 Bandstop Filters. 7 Coupled-Resonator Circuits. 7.1 General Coupling Matrix for Coupled-Resonator Filters. 7.2 General Theory of Couplings. 7.3 General Formulation for Extracting Coupling Coefficient k. 7.4 Formulation for Extracting External Quality Factor Qe. 7.5 Numerical Examples. 7.6 General Coupling Matrix Including Source and Load. 8 CAD for Low-Cost and High-Volume Production. 8.1 Computer-Aided Design (CAD) Tools. 8.2 Computer-Aided Analysis (CAA). 8.3 Filter Synthesis by Optimization. 8.4 CAD Examples. 9 Advanced RF/Microwave Filters. 9.1 Selective Filters with a Single Pair of Transmission Zeros. 9.2 Cascaded Quadruplet (CQ) Filters. 9.3 Trisection and Cascaded Trisection (CT) Filters. 9.4 Advanced Filters with Transmission-Line Inserted Inverters. 9.5 Linear-Phase Filters. 9.6 Extracted Pole Filters. 9.7 Canonical Filters. 9.8 Multiband Filters. 10 Compact Filters and Filter Miniaturization. 10.1 Miniature Open-Loop and Hairpin Resonator Filters. 10.2 Slow-Wave Resonator Filters. 10.3 Miniature Dual-Mode Resonator Filters. 10.4 Lumped-Element Filters. 10.5 Miniature Filters Using High Dielectric-Constant Substrates. 10.6 Multilayer Filters. 11 Superconducting Filters. 11.1 High-Temperature Superconducting (HTS) Materials. 11.2 HTS Filters for Mobile Communications. 11.3 HTS Filters for Satellite Communications. 11.4 HTS Filters for Radio Astronomy and Radar. 11.5 High-Power HTS Filters. 11.6 Cryogenic Package. 12 Ultra-Wideband (UWB) Filters. 12.1 UWB Filters with Short-Circuited Stubs. 12.2 UWB-Coupled Resonator Filters. 12.3 Quasilumped Element UWB Filters. 12.4 UWB Filters Using Cascaded Miniature High- And Lowpass Filters. 12.5 UWB Filters with Notch Band(s). 13 Tunable and Reconfigurable Filters. 13.1 Tunable Combline Filters. 13.2 Tunable Open-Loop Filters without Via-Hole Grounding. 13.3 Reconfigurable Dual-Mode Bandpass Filters. 13.4 Wideband Filters with Reconfigurable Bandwidth. 13.5 Reconfigurable UWB Filters. 13.6 RF MEMS Reconfigurable Filters. 13.7 Piezoelectric Transducer Tunable Filters. 13.8 Ferroelectric Tunable Filters. Appendix: Useful Constants and Data. A.1 Physical Constants. A.2 Conductivity of Metals at 25 C (298K). A.3 Electical Resistivity rho in 10-8 m of Metals. A.4 Properties of Dielectric Substrates. Index.

Microstrip filters for RF/microwave applications

Theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Energy of photons in long wavelength lasers is less than the work function of the photocathode material, and can only emit electrons via tunneling through the potential barrier. The optical resonance effect (e.g. plasmonic resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design optical resonant surfaces (e.g. metasurfaces) for electron emission applications.

Electron emission by long and short wavelength lasers: essentials for the design of plasmonic photocathodes.

Recent advances in topologically robust waveguiding for electromagnetic systems have presented opportunities for improving practical photonic and microwave devices. To bring this rich area of physics within the reach of application, it is critical for such systems to be interfaced with classical, continuous waveguiding and transmission line technology. This Letter presents a compact, highly efficient transition from a classical metallic transmission line to a topologically nontrivial line wave emulating the quantum spin Hall effect. A zero-gap antipodal slot line is used as the starting transmission line, which is then coupled to the topological metasurface via a field matching procedure. Additional modifications to the interface between the two structures to eliminate unwanted edge coupling improves transmission further. A simulated loss analysis isolates the effect of the transitions from the rest of the structure, showing a loss contribution of only 2.1% per classical-to-topological conversion. Using the transition, a quantitative characterization of the robustness of common topologically protected devices is presented. This design lays the foundation to integrate topologically robust metasurface transmission lines to traditional systems, opening the door to future uses of such structures in systems.

Classical-to-Topological Transmission Line Couplers

Periodically loading non-Foster circuits (NFCs) in a conventional waveguide has been proved to be possible for achieving broadband non-dispersive fast-wave (FW) propagation. However, the unconditional stability of such structures has been argued due to the multiple NFC loadings. Despite the potential instability, it is demonstrated that the NFC-loaded waveguide can still be stable for specific terminations, in particular, with the 50 Ω load that is commonly used in radio frequency/microwave applications. For purpose of demonstration, a NFC-loaded waveguide that contains substantially more unit cells than in prior work has been designed and measured, showing a stable and causal FW propagation with a 1.2 c phase velocity over the bandwidth of 80–120 MHz.

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Stable multiple non-Foster circuits loaded waveguide for broadband non-dispersive fast-wave propagation

In this paper, we present a computational and experimental design of a metasurface for broadband microwave antenna isolation Our current emphasis is on the development of a high-impedance surface (HIS) that enables broadband isolation between transmit and receive antennas For our specific HIS, we have formed a cascade of HIS unit cells and have thus expanded the isolation to provide 56 dB/meter over one octave (75 to 18 GHz) relative to the bare metal ground plane Computational models are used to design the cascaded structure to assure maximum isolation amplitude and bandwidth

Cascaded metasurfaces for broadband antenna isolation

A low profile, wide band gap antenna having a high impedance surface (10), the high impedance surface (10) includg a conductive plane (14) and an array of conductive elements (12) spaced from the conductive plane (14) by a distance which is no greater than 10% of a wavelength of an operating frequency of the antenna structure. The conductive plane (14) has an opening (20) therein which is driven by an antgenna driving element (22) adjacent the opening in the conductive plane (14).

Daniel F. Sievenpiper

Papers

Electron emission by long and short wavelength lasers: essentials for the design of plasmonic photocathodes.

Classical-to-Topological Transmission Line Couplers

Stable multiple non-Foster circuits loaded waveguide for broadband non-dispersive fast-wave propagation

Cascaded metasurfaces for broadband antenna isolation

Low profile slot or aperture antenna using backside fed frequency selective surface