Search

The single-mode bosonic channel is addressed with classical interference in the modulation and with side information at the transmitter. This model can viewed as the quantum counterpart of the classical random-parameter Gaussian channel. Based on Costa's writing-on-dirty-paper result (1983), the effect of the channel parameter can be canceled even when the decoder has no side information, and regardless of the input power constraint. For both homodyne and heterodyne detection with a coherent-state protocol, the model reduces to a classical channel with either real or complex-valued Gaussian noise. Thereby, by applying Costa's dirty paper coding strategy, we observe that the effect of the classical interference can be canceled for those channels as well. Then, we consider the bosonic channel with joint detection, for which the classical results do not apply, and derive a dirty-paper coding lower bound. Furthermore, considering the special case of a pure-loss bosonic channel, we demonstrate that the optimal coefficient for dirty paper coding is not necessarily the MMSE estimator coefficient as in the classical setting.

In this paper, the partial discharge (PD) in oil-paper insulation cavity is conducted under the voltage of $AC,\ Y/\mathrm{\Delta}$ connection and Y/Y connection, respectively. The low-amplitude and high-repetition PD under the AC voltage is observed, the high-amplitude and a low-repetition PD is acquired under the given valve voltages. The discharge mainly occurs at the rising edge of the valve voltage waveforms. The $Q_{max}$ of the discharge of $Y/\mathrm{\Delta}$ and Y/Y connections is 2 and 2.5 times the Qmax under the AC voltage, respectively. The average discharge $Q_{mean}$ of $Y/\mathrm{\Delta}$ and Y/Y connections is 3 and 2 times Qmean obtained under the AC voltage, respectively. The total discharge Q tatol of both valve voltage waveforms is higher than that under the AC voltage. The test results also show that the PD is severely affected by the voltage waveform as the voltage distortion is observed in the experiment. This work may provide a reference for the improvement of insulation design and the factory test of converter transformers.

A circularly polarised metasurface is proposed in this paper. The design of the surface aims at improving the performance of a hybrid radiating structure made of one dipole and an Archimedean spiral antenna designed on the same surface. The antennas operate in UHF and lower European UWB bands, respectively, and realize a compact single-port antenna for future generation autonomous RFID tags. A High Impedance Surface (HIS) is employed as the ground plane to serve as a Perfect Magnetic Conductor (PMC), with the double purpose to maintain both the circular polarization in the UWB band and the low-profile stack-up, while assuring an insensitive behaviour to the background material.

This paper covers results of full wave analysis and optimization of electrical performance of key components of the multimode circularly polarised X-band monopulse feed, namely, the wideband circular corrugated horn supporting propagation of hybrid modes HE11 and HE21, the wideband multiholes directional coupler of orthogonal modes H21 and the wideband compact septum polariser. Also, results of design and laboratory testing in anechoic chamber of the whole manufactured monopulse feed prototype in the frequency range 7.7-8.5 GHz are presented. The simulated and measured results show that the developed feed has excellent sum and difference channels radiation patterns, high isolation between these channels and high crosspolar discrimination. Therefore the proposed feed can be considered as a promising candidate for application in ground station reflector antennas to provide capability of high accuracy autotracking and reception of high data rate information in both right hand circular polarisation (RHCP) and left hand circular polarisation (LHCP) from low Earth orbit (LEO) satellites.

Kramers-Kronig function is treated as a universal relationship between the real and imaginary parts of a frequency domain response system. The present study aims at establishing this relationship’s specific implementation strategy in the field of frequency domain spectroscopy which is a promising insulation condition assessment method for power equipment. To achieve this, the physical meaning of dielectric material’s complex permittivity spectrum is discussed first, based on which Kramers-Kronig function’s role in the data processing is made clear. Further, the present study deduces a simplified formula from Kramers-Kronig function’s original form that is capable for oil-paper’s frequency domain spectrum data analysis. On this basis, an analysis model of real part and imaginary part of complex permittivity based on Kramers-Kronig relationship is established, and the mechanism analysis in the testing band is obtained. The result shows that a relaxation loss peak co-exists with AC conduction process in the low frequency range of oil-paper insulation’s frequency domain spectroscopy. Weight of each dielectric process is compared as well.

“Microstrip Patch Antenna” has been widely and intensively investigated and applied in wireless system in the past five decades. To alleviate the narrow bandwidth of the antennas, many techniques have been proposed. One of them is to reduce the Q-factor for increasing the radiation from the antenna. The bandwidth is enhanced from 1% to 10% by increasing the thickness from 1% to 6% times wavelength and removing the dense dielectric of substrate supporting the radiating patch. Furthermore, U-slotted patch has been proposed to introduce additional modes to further increase the bandwidth to 30 ~ 40%. L-probe is another wideband feeding structure to perfectly excite the broadband suspended plate antenna. The both are invented in 1990s by K. F. Lee and K. M. Luk. Recently, a new type of slotted patch antennas like an array of mushroom and later a mosaic has been proposed for bandwidth enhancement in terms of impedance and radiation patterns. The mosaic antenna is still printed onto a piece of fulldielectric PCB. The grid-slots on the patch significantly increase the radiation and change the dispersion response of patch antenna acting as a metasurface. With an aperture coupling feeding structure, the two adjacent modes are well excited and generate identical radiation performance. More and more variations of the metasurface mosaic antenna have been proposed and developed for performance enhancement and new functionalities.

We develop a modal method for radially inhomogeneous waveguides. The formulation is derived with the two transverse components of the magnetic field. The algebraic eigensystem is solved by using Tchebycheff polynomials and a tau method.

Atomic functions (AF) are infinitely differentiable compactly supported solutions of a functional-differential equations. The review presents a brief analysis of current publications on AF and related topics and some new results discussed in detail.

A high-speed and linear balanced avalanche photodiode is presented, enabling coherent self-homodyne receivers. Such a device would reduce cost and power consumption for intra-datacenter links.

The contribution of hole trapping and detrapping $(\Delta\mathbf{V}_{\mathbf{HT}})$ to overall threshold voltage shift $(\Delta \mathbf{V}_{\mathbf{T}})$ during and after Negative Bias Temperature Instability (NBTI) stress is obtained using an Activated Barrier Double Well Thermionic (ABDWT) model. ABDWT, along with generated interface $(\Delta \mathbf{V}_{\mathbf{IT}})$ and bulk $(\Delta \mathbf{V}_{\mathbf{OT}})$ trap kinetics computed by the previously published BTI Analysis Tool (BAT), can explain $\Delta \mathbf{V}_{\mathbf{T}}$ time kinetics during and after DC and AC stress and mixed DC-AC stress under varying experimental conditions. The model is validated using measured data from MOSFETs with High-K Metal Gate (HKMG) based gate insulator processes.

At present, there are a large number of nonlinear electrical equipment in the power system, which leads to higher and higher harmonic components in the system. In addition, the large number of new energy access, such as photovoltaic, wind power and so on, also introduces large harmonic interference. Harmonic has a certain influence on the loss of distribution transformer in operation. Based on the principle of harmonic current acting on transformer, the winding resistance loss, winding eddy current loss and stray loss of distribution transformer under non-rated condition are analyzed in this paper. The load loss calculation model in the IEEE Std C57.110 is further revised. Based on the model established in this paper, the selected example transformer is calculated and analyzed. The accuracy of the calculation model established in this paper is verified by the analysis results. The larger the harmonic distortion rate and harmonic frequency, the faster the load loss of distribution transformer increases.

This paper presents a compact paper-based rectenna with dual frequency operation. The rectenna is composed of a microstrip antenna designed on paper, in which an air gap is introduced between the patch and the ground plane to overcome the low-thickness and high-loss characteristics of the conventional paper substrate. This allows the microstrip antenna to reach a high radiation efficiency and a large bandwidth. Additionally, a miniaturization technique is utilized to reduce the antenna dimensions imposed by the low permittivity of the air. The absence of matching network between the antenna and the rectifier ensures a very compact size as well as limited insertion losses at the rectifier level and results in a high RF -DC conversion efficiency in the two frequency bands 1.8 and 2.4 GHz. The rectenna prototype shows experimental conversion efficiencies of 25 and 19 % at 1 $\mu \mathrm{W}/\mathrm{cm}^{2}$ and 55 and 44 % at 10 $\mu \mathrm{W}/\mathrm{cm}^{2}$ at 1.8 and 2.45 GHz, respectively, corresponding to output DC voltages of 208, 190 and 933 and 923 mV. Furthermore, output DC voltages of 93 and 550 $\mathrm{mV}$ are maintained over the band 1.75-2.6 GHz at 1 and 10 $\mu \mathrm{W}/\mathrm{cm}^{2}$ respectively. The rectenna prototype features a weight of 1.5 $\mathrm{g}$ and dimensions of 0.21 $\lambda_{o}\mathrm{x}0.21\lambda_{o}\mathrm{x}0.06\lambda_{o}$ .

A reconfigurable microstrip antenna with a dual-polarization beam-scanning feature is proposed in this paper. The proposed antenna is based on microstrip Yagi-Uda antenna comprised of a driven square patch and four parasitic square patches. Two different feed ports are utilized to separately excite two orthogonal modes for dual-polarization operation. The capability of beam-scanning is realized by loading a narrow loop slot and four varactors within each parasitic patch. By tuning the capacitance value of the varactors, the parasitic patch can act as a director or a reflector for the driven patch. Simulation results demonstrate that the beam can be scanned in 2D plane. The simulated cross-polarization discriminations are higher than 20 dB in all seven states presented in this paper. The proposed antenna is in fabrication and experimental results will be provided in the final submission.

The IBM Power Block is a high power density, low cost 48 V input DC-DC converter, designed to source up to 107 A of continuous output current to processors in high performance computing (HPC) and datacenter servers. Peak efficiency for a 0.75 V output is 90.6% at 45 A and 85.1% at 107 A. An active clamp forward converter (ACFC) architecture uses a pair of primary FETs and a pair of secondary FETs, separated by a planar transformer. A custom timing chip provides four gate timing signals, whose delays can be stored in internal fuses or set through a serial interface. Transformer and inductor magnetics are integrated into a single ferrite structure that allows induced electro motive forces (EMFs) to cancel, thereby providing near zero output current ripple at 0.75 V and low ripple 0.5 V to 1.0 V. Designed for 1 U servers, the Power Block has a 13 mm x 16 mm footprint and a 19 mm height. The electrical output contact’s flat top permits mounting a heat sink or cold plate.

Stimulated Electromagnetic Emission (SEE) is secondary radiation produced during experiments where high power high frequency (HF) radio waves interact with the ionosphere. SEE has been a vibrant area of investigation for the past three decades and SEE has been developed into an important remote sensing tool for the ionosphere with substantial potential for aeronomy studies. Past experiments primarily considered emissions within a bandwidth of 100 kHz of the pump (transmit) frequency, so-called wideband SEE (WSEE), but more recent work has concentrated on SEE within 1kHz of the pump frequency, so-called narrowband SEE (NSEE), as well as the pump frequency harmonic. A brief review of the recent experimental observations of NSEE are presented as well as some basic concepts of the nonlinear wave-wave processes that produce NSEE. Some new potential applications are discussed as well.

This study presents design, implementation and test of a read-out system for disposable paper-based sensors. Proposed system basically consists of a Strathmore®300 series Bristol paper-based cantilever with the dimension of 1cm × 3.5cm and the thickness of roughly 400µm which is covered with a thin piezoresistive layer and a read-out circuitry that is composed of a Wheatstone Bridge circuit and instrumentation amplifier (INA128). Proposed read-out system is simulated, implemented and tested. The sensitivity of the proposed read-out system is measured as 0.25mV/µm for $\Delta V_{out}$ and 15mΩ/µm for $\Delta R_{PR}$.

A novel broadband concave paper antenna is proposed for low cost and conformal applications. The new design is a three-dimensional monopole antenna. Owing to the concave flexible paper substrate, the proposed antenna is easy to integrate with the packing case or the communication product. The broadband antenna can be used in the applications covering the 0.903–2.63 GHz band, such as 2G, 3G, and WLAN. Its gain is 3.8 dBi at 0.915 GHz, 3.5 dBi at 1.0 GHz, 2.8 dBi at 1.8 GHz, and 4.8 dBi at 2.45 GHz. Experiments validate the simulated results of our antenna.

Ultrasonic signals can be utilized as a viable communication method to transmit information through gas, liquid, and solid channels or a mixed media consisting of a solid interfaced with liquid and/or gas. Underwater communication channels using sound waves cause many challenges, often unforeseen, due to absorption, scattering, refractions, reverberations, multipaths, doppler shifts, temperature, salinity, and acoustic scintillation. Ultrasonic communication through the air is less prone to the environmental challenges that are often encountered in the underwater communications. Ultrasonic communication in solid channels is also adversely affected by absorption, scattering, refractions, reverberations, beam skewing, dispersion, mode conversation, multipaths, and above all these challenges are compounded by the geometrical structure of solids and type of ultrasonic waves. With solid structures many different ultrasonic wave types can be generated including Longitudinal (Compressional), Shear (Transverse), Surface-Rayleigh, Plate-Lamb (Symmetrical or Extensional Mode and Asymmetric or Flexural Mode), Plate-Love, and Stoneley (Leaky Rayleigh). The type of waves is governed by the frequency and angle of the incident waves on a solid structure where the quality of the signal for communication is limited by the composition and geometrical shape of the solids. For this study we have developed a testbed platform using the ZYNQ SoC (System-on-Chip) FPGA by Xilinx which offers reconfigurability and high-performance computational capability, high speed signal converters, power amplifiers for excitation of transducers, low noise receiving amplifiers and high frequency ultrasonic transducers for transmitting and receiving information. Theoretically, ASK (amplitude shift keying) or any form of digital modulation can be realized with the system using the concept of the software-defined ultrasonic communications (SDUC). In practice, the received signal is very complex, primarily caused by dispersion, reverberation, and multipath effects. We have examined SDUC system using AM (Amplitude Modulation), OOK (on and off keying), BPSK (Binary Phase Shift Keying), QPSK (quadrature phase shift keying), and OFDM (orthogonal frequency-division multiplexing). This system is tested using differently structured solid channels (such as blocks, plates and pipes); and bitrates and bit rate errors are compared using 2.5 MHz ultrasonic transducers. Furthermore, this paper presents an overview of using EMAT for ultrasonic communications in metal channels.

This paper proposes an accurate 3D segmentation method for visualization and quantitative analysis of differentiation activities of mouse embryonic stem (ES) cells using time-lapse confocal fluorescence microscopy images. One of critical tasks in ES cell segmentation arises due to that ES cell nuclei are often close to each other. Several segmentation methods by convexities and concavities on cell or nucleus contours to detect possible touching cells or nuclei were proposed. Comparing to image processing methods, these methods are more accurate in some conditions, however, still cannot detect touching nuclei without concavities on nucleus contours. Our method uses the nucleus size and convex, concave, strait and extrusion features on nucleus contour to touch a boundary between touching cell nuclei in 2D slices and interslices. Experimental results show our method can well detect touching boundaries of 2D and 3D nucleus for confocal microscopy images of mouse ES cells in an early stage of differentiating into neural progenitor cells. Based on the accurate ES cell segmentation, cell activities (velocities and shape changes) during differentiation can be accurately visualized and quantitatively analyzed.

This paper presents results from the (to our knowledge) first dynamic double-directionally resolved measurement campaign at mm-wave frequencies for an outdoor microcellular scenario. The measurements are performed with USC's real- time channel sounder equipped with phased array antennas that can steer beams electrically in microseconds, allowing directional measurements in dynamic environments. Exploiting the phase coherency of the setup, the multi-path components can be tracked over time to investigate the temporal dependencies of the channel characteristics. We present results for time-varying path-loss, delay spread, mean angles and angular spreads observed at the transmitter (TX) and receiver (RX) in the presence of moving vehicles and pedestrians. Additionally, we investigate excess losses observed due to blockage by vehicles and compare the cases when TX and RX are using fixed beams or when they are capable of adjusting beam directions dynamically.

This paper concerns the problem of data inversion in microwave imaging for biomedical applications. In particular, the integral equations of the inverse scattering problem are solved — in a regularized sense — by a new iterative procedure based on a conjugate gradient method. The approach is developed in Lp Banach spaces. Transverse magnetic illumination conditions are assumed in a tomographic configuration. The detection of hemorrhagic brain strokes is considered in the reported numerical simulations.

In this work modal analysis of optomagnonic resonators composed by magnetic garnet spheres is presented. The linearly and partial circularly polarized whispering-gallery-modes (WGMs) appearing in magneto-optical (MO) coupling, are theoretically verified, and rigorous mode designation is attributed to them. To carry out the study, a volume integral equation method is employed which supports anisotropic permittivities. The method is particularly tuned for addressing high mode order resonances. To this end, the volume integral equation is supplmemented by an asymptotic vectorial basis, enabling the accurate computation of high order eigenbasis required to solve the problem.

The present study describes the entropy generation on peristaltic wave of Nanofluid with the influence of MHD. The governing equation of continuity, nano particle, equation of motion and entropy generation equation are solved by neglecting the inertial forces and taking long wavelength approximation. With the help of perturbation method, the resulting highly non-linear coupled partial differential equation has been solved analytically. Some prominent graphical results of the pertinent physical parameters for temperature profile, pressure distribution, and entropy generation are presented. Correlation between the entropy generation and some other parameters has been analyzed numerically. Because it is very important to find the sensitivity of each parameter on entropy generation. Moreover, Magnetohydrodynamics plays a vital role in the application of pumping the fluids for pulsating and non-pulsating continues flow in different micro channel designs and it is also very helpful to control the flow.

PDC measurement and analysis is one of widely used tool for reliable diagnosis of power transformer insulation. In different reported methods of analysis it is considered that polarization current is composed of the current due to dipole movement and conduction current. Similarly the depolarization current is assumed to be composed of relaxation of dipoles. However when the dc conduction effect is removed from polarization current it is found the resulting current is not similar to the measured depolarization current. This deviation in both the currents show the presence of nonlinearity in the system. This nonlinearity arises due to migration of trapped charges that reside at the interfacial region of oil-paper insulation. The present paper shows the effect of such free charge on some important performance parameters like paper moisture and zero of Transfer Function of Classical Debye Model.

The rise/fall time mismatch in a differential signal is responsible for a serious common-mode (CM) issue in high-speed CMOS serializer/deserializer (SERDES) transmitters (Txs). The non-linear parasitic impedance variations of the switching devices and differences in parasitic impedances in the charging and discharging loop produce deterministic spurs on the CM voltage that generate certain spectral tones at twice the Nyquist frequency, causing the electromagnetic compatibility (EMC) failure. The CM radiation is generally more significant than differential-mode (DM) radiation, and therefore suppressing CM noise is essential for improving EMC performance. This paper presents a new circuit design perspective to address the CM noise issue in a source-series terminated (SST) output driver by calibrating parallel impedance scaled SST stages. Simulated in a 65-nm CMOS process, our results indicate that adjusting the MOS devices circumvents the CM noise by more than 65% in the worst case scenario as it affects most of the output CM noise profile.

This paper presents an analysis for the electromagnetic interference (EMI) related common-mode (CM) noise in differential high-speed data links with different signal modulation schemes, e.g. non-return-to-zero (NRZ) and 4-level pulse amplitude modulation (PAM-4). The CM noises, introduced by the mismatch of data rising and falling edges in both cases, exhibit the similar positive correlation with signal swing, but due to the complexity of PAM-4 signal, the amplitude distortion leads to different CM noise behavior.

In this paper, we propose a design method for a chassis MIMO antenna based on characteristic mode theory. Specifically, we provide a way to use a chassis with one axis of symmetry as a multiport MIMO antenna. The method utilizes a combination of characteristic mode and a mode-decoupling network, and suggests a way to design an inductive coupling element to excite specific characteristic modes while simplifying the mode-decoupling network.

This paper presents some sensing strategies for microwave sensors based on symmetry properties and metamaterial-inspired resonators. Symmetry disruption is the key aspect in all the cases. The sensors consist of a transmission line loaded with one or two resonant elements in a symmetric configuration. Two types of sensors are considered: (i) coupling modulation sensors, and (ii) frequency splitting sensors. The former are useful to monitor spatial variables and are of particular interest for angular displacement and velocity sensors. Frequency splitting sensors can be used as comparators or for differential measurements of permittivities in dielectric samples. Examples of applications are reported.

We report a unique highly-linear, low-complexity, selectable slope, optical electric field frequency discriminator (FD) filter as novel phase-modulated/frequency-modulated-tointensity- modulated (PM/FM-to-IM) converter. We refer to this FD as Sin-Sin2 FD filter. Here, we review its different aspects, including its (i) surprisingly simple device design, (ii) excellent linearity performance, and (iii) unique programmable features. Compared with other linear FD filters having 6 to 11 Mach– Zehnder interferometer (MZI) elements, Sin-Sin2 uses only two MZIs and one Y-branch combiner. Its unique programmable features include (i) selectable dual-slope functionality via dynamic control of device’s path length, (ii) selectable dual-slope functionality via tuning the wavelength of laser source, (iii) switchable positive/negative slope signs, and (iv) inherent compensation property. We also introduce simplified link architectures that maximize these features.

This paper presents the review on different types of corrugated waveguides and the antennas for far field radiation pattern. This kind of antennas having a better gain and directivity and the side lobe levels are comparatively low. The side lobe levels can be further reduced by the applying the concept of corrugation to the walls. The significant disadvantage of TE 11 mode, side lobes and cross-polarization, is reduced by the HE 11 mode. Now a days, working with a new type of corrugated horn antenna, consists on generating the fundamental Gaussian beam directly from the TE 11 mode. These antennas are used when high degree of symmetry in radiation field and low cross polarization with high gain and pencil beam is required. This kind of Gaussian profile horn antenna having lower aperture in size.

This research presents a passive UHF RFID tag antenna design. The compact size antenna can be achieved by using modified split ring resonator (SRR). The structure contains a square SRR connected with a circular SRR on the radiating part to increase the antenna length. The proposed tag antenna is a paper-based which uses the paper as the substrate. It is a low-cost, flexible and suitable for mass production. The proposed tag antenna size is 38 mm × 38 mm and the |S11| of better than -10 dB that can cover the frequency range of 920–925 MHz. The maximum read range is 3.20 m. The modified SRR can decrease the antenna size.

In this paper, channel characterization of Rayleigh fading channel at 28 GHz band is investigated. FMCW (Frequency-modulated continuous wave) radar is used as a channel sounder. The measurement is carried out inside the reverberation chamber with two different received antennas; one has 72.29° and the other has 2.40o of 3 dB beamwidth on azimuth plane. Different cases has examined with different arrangements of microwave absorbers. The obtained scattered plots and envelope distributions of Rayleigh fading channel has shown and discussed.

The Precision Array for Probing the Epoch of Reionization (PAPER) is a focused experiment aimed at detecting the spatial power spectrum of neutral hydrogen emission during the Epoch of Reionization (EoR). PAPER is an interferometer operating from 100 – 200 MHz at the site of the future Square Kilometre Array (SKA) site in South Africa. The PAPER antennas measure linear polarization and the correlator produces full-Stokes output. PAPER currently has 64 antennas and has just completed a 141-day science integration. An expansion to 128 antennas and another long observing campaign will be complete in late 2013.

The Precision Array for Probing the Epoch of Reionization (PAPER) is a focused experiment aimed at detecting the spatial power spectrum of neutral hydrogen emission during the Epoch of Reionization (EoR). PAPER is an interferometer operating from 100 – 200 MHz, with antennas measuring linear polarization and a correlator producing full-Stokes output. The science array is located at the site of the future Square Kilometre Array (SKA) site in South Africa, with a prototyping and test facility in Green Bank, WV. A staged build-out of PAPER South Africa (PSA) began in late 2009. PAPER has been obtaining science-grade observations since late 2011, when 32 dipoles (PSA-32) began taking data full-Stokes data. PAPER currently has 64 antennas and has just completed a 141-day science integration (PSA-64). An expansion to 128 antennas and another long observing campaign will be complete in late 2013.

The radio propagation characteristics of 28 GHz were investigated by using a FMCW (Frequency Modulated Continuous Wave) radar system in a reverberation chamber for the small-fading of Rayleigh and Rician conditions.

Significant effort has recently been turned to the problem of detecting and characterizing intergalactic hydrogen prior to its complete ionization by stars, occurring sometime before t=950Ma (z=6). The distribution of HI, visible in redshifted 21cm radio emission, is one of the few observables into the onset of non-linear structure leading to the birth of the first stars and galaxies. Before it was ionized by stellar UV radiation, HI was found throughout the universe, roughly tracing out the underlying matter distribution and temperature. HI 21cm emission from this epoch (6 < z < 12) is redshifted into the VHF radio band (100 < f < 200 MHz) and with a observer frequency depending on redshift/distance provides a fully three dimensional view. The emission is expected to have surface brightness of ∼25mK with a non-gaussian distribution and most power occurring on scales of 10cMpc.

To enable a fair appreciation of Kirchhoff's approach, this paper reminds the readers of the content of the original paper by Kirchhoff presented more than 125 years ago here in Berlin, and points out especially that what has been termed Kirchhoff's approach in many textbooks is only a small portion of Kirchhoff's approach as formulated in his 1882 paper.

Extreme electromagnetic anomalies in the ionosphere and and their future implications. There are many unusual and interesting anomalies in the ionosphere resulting from abnormal and even severe electromagnetic conditions. These anomalies are not often recognised as being any more significant than simply unusual. However they may have long term implications which should be considered in the light of the continually changing global atmosphere. This paper will not attempt to cover the whole gamut of ionospheric anomalies but will suggest somereasoning behind the occurrence of some of them, which gives opportunities for future consideration of the phenomenon.

Magneto optical imaging of small magnetic fields. High resolution imaging small magnetic fields is useful in a number of fields ranging from material to medical sciences. While sensitive detection of magnetic fields has been achieved with SQUIDS or atom vapor magnetometers, sensitive imaging with high sensitivity has remained elusive so far. Using magneto-optically active systems - especially the nitrogen-vacancy center in diamond - may become an extremely valuable tool in this respect. The talk will describe how to achieve pT/Hz1/2 with NV ensemble-based magnetometry and demonstrate how to detect the magnetic field of single proteins with nm resolution.

Three network architectures, compatible with passive optical networks, for future hybrid quantum-classical networks are proposed and compared. These setups rely on three different schemes for quantum key distribution (QKD): BB84, entanglement-based QKD, and measurement-device-independent QKD (MDI-QKD). It turns out that, while for small-to-moderatesize networks BB84 supports the highest secret key generation rate, it may fail to support large numbers of users. Its cost implications are also expected to be higher than other setups. For large networks, MDI-QKD offers the highest key rate if fast single-photon detectors are employed. Entanglement-based networks offer the longest security distance among the three setups. MDI-QKD is, however, the only architecture resilient to detection loopholes and possibly the most favorable with its less demanding end-user technology. Entanglement-based and MDI-QKD setups can both be combined with quantum repeater systems to allow for long-distance QKD with no trust constraints on the service provider.

In this paper, we present two systems for the generation and distribution of ultrawideband (UWB) pulse signals in the optical domain. The first system consists of a single-wavelength laser source, an electrooptic phase modulator (EOPM), a length of single-mode fiber (SMF) and a photodetector (PD). The combination of the EOPM, the SMF link and the PD forms an all-optical microwave bandpass filter, which is used to generate Gaussian doublet pulses at the receiver front-end. In the second system, pulsed light is wavelength-converted to phase-modulated light via cross-phase modulation in a nonlinear fiber. A fiber Bragg grating (FBG) that serves as a frequency discriminator is connected at the output of the nonlinear fiber. By reflecting the phase- modulated light at the slopes of the FBG, electrical monocycle and doublet pulses are obtained at the output of the PD. Experimental results measured in both temporal and frequency domains are presented. The use of the second configuration to implement pulse on-off, polarity and shape modulations in the optical domain is also discussed, which provides the potential for fully exploiting the advantages provided by UWB-over-fiber networks

Quantum and high-field effects present in a nanoscale MOSFET are modeled and data processed using MATLAB. The drift response to the electric field is modeled after the intrinsic velocity that is shown to be the ultimate limit to the saturation velocity in a very high electric field. The ballistic intrinsic velocity arises from the fact that randomly oriented velocity vectors in zero electric field are streamlined and become unidirectional. The presence of a quantum emission lowers the saturation velocity. The drain carrier velocity is revealed to be smaller than the saturation velocity due to the presence of the finite electric field at the drain of a MOSFET. The velocity so obtained is considered in modeling the current-voltage characteristics of a MOSFET channel in the inversion regime and excellent agreement is obtained with the experimental data on an 80-nm channel.

External force at the end-effector is often required for the force control of robotic manipulator. In some cases, the force information measured by wrist force sensor consists of the external force and the undesired inertial force arising from the acceleration of the end-effector. Up to now, il: is still difficult to extract the external force exactly for the insufficiency of acceleration information. A novel six-axis accelerometer in. the type of dual annular membranes structure is presented in this paper. It can simultaneously measure all three linear acceleration components ax, ay, az, and three angular acceleration components ax, ay, az which can be used to extract the external forces. The Finite Element Method (FEM) simulations were carried out to optimize the configuration of strain gauges. The analysis of the rated strains and interference strains indicates that the accelerometer has a low level cross-sensitivity. The characteristic experiment shows that the linearity of the accelerometer is good with minor interference errors. It also reveals that the rated strains and interference strains are in good correspondence with the results from the FEM simulations.

This paper presents a general analysis of the 3rd-order nonlinearity of a differential common-emitter (CE) radio frequency (RF) amplifier and an improved way to cancel the 3rd-order nonlinearity. A SiGe BiCMOS mixer is designed, based on the 3rd-order cancellation scheme. The mixer achieves +6 dBm IIP3, 15 dB gain and 7.7 dB DSB NF with only 2.2 mA current at 2.1 GHz. This performance exceeds that of previously reported active mixers in this frequency range.