pinecone/core-2020-05-10-deduplication huggingface dataset:
Compact coplanar waveguide bandpass filter based on coupled S-shaped split ring resonators

This letter is focused on the application of coupled single-layer S-shaped split ring resonators (S-SRRs) to the design of highly compact bandpass filters in coplanar waveguide (CPW) technology. S-SRRs have been previously demonstrated as miniaturized resonators, particularly suited for applications in conjunction with coplanar line geometries. However, size reduction of CPW filters based on impedance inverters and S-SRRs is limited by the inverters. Therefore, this letter proposes an alternative geometry of CPW bandpass filters employing S-SRRs in a configuration based on the theory of coupled resonators. A highly compact third-order bandpass filter is designed using this principle, and the proposed approach is validated through experiment, demonstrating competitive filter performance achieved in an extremely small area
An ultra-wideband SiGe BiCMOS LNA for w-band applications

This article presents the design steps and implementation of a W-band ultra-wideband low noise amplifier (LNA) for both automotive and imaging applications. Three amplifiers based on common-emitter topology with different configurations are manufactured using IHP 0.13 mu m SiGe BiCMOS 300/500 GHz (f(t)/f(max)) SG13G2 technology. A three-stage single-ended structure is proposed for ultra-wideband imaging purposes. As the results are analyzed, this 0.2 mm(2) LNA can operate in a 25 GHz of measured 3-dB bandwidth in W-band with 21 dB peak gain and 4.9 dB average noise figure using 1.5 V supply voltage. It consumes 50 mW of power in the edge operation conditions and the output 1 dB compression point is found as -4 dBm. To the authors' knowledge, this chip achieves one of the best overall performances compared to other W-band LNAs
Integrated decoupling and matching network incorporated in the ground plane of a compact monopole array

Compact arrays enable various applications such as antenna beam-forming and multi-input, multi-output (MIMO) schemes on limited-size platforms. The reduced element spacing in compact arrays introduces high levels of mutual coupling which can affect the performance of the adaptive array. This coupling causes a mismatch at the input ports, which disturbs the performance of the individual elements in the array and affects the implementation of beam steering. In this article, a reactive decoupling network for a 3-element monopole array is used to establish port isolation while simultaneously matching input impedance at each port to the system impendence. The integrated decoupling and matching network is incorporated in the ground plane of the monopole array, providing further development scope for beamforming using phase shifters and power splitters in double-layered circuits
Compact Orthogonal Wideband Printed MIMO Antenna for WiFi/WLAN/LTE Applications

YesThis study presents a wideband multiple-input-multiple-output (MIMO) antenna for Wifi/WLAN/LTE applications. The antenna consists of two triangular patches as the radiating elements placed orthogonally to each other. Two T-slots and a rectangular slot were etched on the ground plane to improve return loss and isolation. The total dimension of the proposed antenna is 30 x 30 mm2. The antenna yields impedance bandwidth of 101.7% between 2.28 GHz up to 7 GHz with a reflection coefficient of < -10 dB, and mutual coupling of < -14 dB. The results including S-Parameters, MIMO characteristics with analysis of envelope correlation coefficient (ECC), total active reflection coefficient (TARC), capacity loss, channel capacity, VSWR, antenna gain and radiation patterns are evaluated. These characteristics indicate that the proposed antenna is suitable for MIMO wireless applications
Design of dual-mode dual-band photonic crystal bandpass filters for terahertz communication applications

In this study, Photonic Crystal (PhC) dual-mode dual-band bandpass filter is designed and its transmission characteristics are investigated for various configurations. PhC resonator structure is formed by a point defect microcavity that is equipped with one large and three smaller auxiliary perturbation rods. Degenerate modes at each band may also be excited by changing the structure properties of the perturbation. Plane wave expansion method and Finite Difference Time-Domain method are used to analyze the device characteristics. Proposed dual-band dual-mode PhC filter structure can effectively be used for terahertz communication applications
Two axis direction finding antenna system using sum-difference patterns in X band

This work proposes the direction finding antenna system in two axis ((1), (2)) in X band using sum (sigma) and difference () patterns of received signal. Direction finding system is constructed by implementing the microstrip patch antenna array and 180 degrees hybrid rat race ring coupler which generates sigma and patterns of received RF signal. Initially, direction of arrival (DOA) is obtained in one axis, ((1)), vertical direction, using the sigma- patterns of antenna array of two elements. Using the equations of sigma and of two input signals, radiation patterns at different values have been observed in simulation and compared with measured pattern values of constructed circuit. By taking the ratio of to sigma patterns, DOA has been estimated of designed circuit. Another circuit similar to first circuit, oriented at 90 degrees (horizontal direction) has been implemented to estimate the DOA ((2)) in other axis. By taking the 3D radiation patterns of each circuit in anechoic chamber, both circuits are measured for performance; and from 0 to +/- 40 degrees, DOA has been observed with rms error of less than 5 degrees in both axis. At 10 GHz operating frequency, experimental results, using material RT Duroid 5880, show that satisfactory performance can be achieved with proposed setup
Wideband planar monopole antennas for GPS/WLAN/WiMAX/UWB and X-band applications

In this article, two printed planar monopole antennas (PPMA) are presented. In the design of the first PPMA, the structure is divided into sections and they are optimized in the sense of bottom to up strategy. Tapered transitions and inset feed are employed to increase the bandwidth. The antenna operates between 2.37 GHz and 12 GHz with VSWR<2 and an average peak realized gain of 4.95 dB. Therefore, it is suitable for WLAN, WiMAX, UWB, and X-Band applications. The second PPMA is designed by implementing slots on the previous one to include GPS. The resulting antenna operates in the 1.38-1.60 GHz and 2.33-13.74 GHz bands with VSWR<2. As a result, it also includes GPS in addition to the previous bands. The peak realized gain in GPS is 0.47 dB at 1.575 GHz and the average peak realized gain is 4.41 dB for the 2.33-13.74 GHz band. The group delay performances of the proposed PPMAs are also examined and the maximum group delay deviations of the first and the second PPMAs are observed as 1 ns and 1.33 ns, respectively
Enhancing common-mode suppression in microstrip differential lines by means of chirped and multi-tuned electromagnetic bandgaps

This article presents common-mode suppressed microstrip differential lines based on chirped electromagnetic bandgaps (EBGs). To achieve common-mode suppression in a wide band, the common-mode impedance is modulated following a sinusoidal chirping, whereas the differential-mode impedance is kept unaltered, thus ensuring that the line is transparent for that mode. The result is a differential line exhibiting common-mode suppression in a band from 2.45 GHz up to 7.37 GHz centered at 5 GHz (98.4% bandwidth). As compared to previous works, based on single tuned or double tuned EBGs, the proposed technique is useful to achieve wider rejection bands for the common mode. Nevertheless, the authors also propose an alternative based on multi-tuned EBGs, in order to obtain a comparable fractional bandwidth. In both cases, the design procedure is simple, and the ground plane is kept unaltered
Coplanar waveguides loaded with symmetric and asymmetric multisection stepped impedance resonators : modeling and potential applications

This article is focused on the analysis and modeling of coplanar waveguide (CPW) transmission lines loaded with multisection stepped impedance resonators (MS-SIRs), transversely etched on the back substrate side. The considered structure consists of a CPW loaded with a 5-section SIR (5S-SIR) with wide (capacitive) central and external sections cascaded with narrow (inductive) sections. The general case of a 5S-SIR with arbitrary lengths and widths of the different sections is considered. The structure is described by a pair of inductively coupled grounded series resonators coupled to the line through the capacitance of the central 5S-SIR section. If the structure is symmetric, the transmission coefficient exhibits a single transmission zero. Hence, these structures can be used as notch filters exhibiting wide bandwidths, provided the inductance of the 5S-SIR can be made small, and the capacitance can be enhanced by virtue of the broadside coupling. However, if symmetry is broken, two notches separated a distance that depends on the level of asymmetry and inductive coupling appear. Therefore, these structures are also useful for the implementation of differential sensors and comparators. The proposed model is validated through parameter extraction and experiment, and a proof-of-concept of a comparator is reported
An active wideband reference target for the calibration of ground to air radar systems

The radar cross section (RCS) of passive calibration targets is relatively low, which leads to a commensurate increase in the uncertainty of the radar’s calibration. To address this deficiency, an active radar calibration (ARC) target was developed, which was mounted on a small remote controlled tri-copter and used for radar calibration. Results are presented for this relatively small, light weight and cost effective airborne ARC, which is suitable for the calibration of a ground to air RCS measurement system. The static RCS characteristics of the airborne ARC target were measured in a compact range and compared to outdoor measurements with the ARC target mounted on the tri-copter. The airborne capability of the calibration target was used to reduce the effects of multi-path and clutter.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-27602017-05-31hb2016Electrical, Electronic and Computer Engineerin
Increasing the bandwidth of a SiGe HBT LNA with minimum impact on noise figure

This paper introduces a matching technique for highly sensitive integrated broadband low-noise
amplifiers. Noise matching is achieved by the paralleling of identical input transistors. Impedance matching,
based on reducing the number of components to the absolute minimum, is done by using the base-collector
capacitance as network element. Using a 0.13 m silicon-germanium (SiGe) bipolar complementary metal
oxide semiconductor process, simulation results indicate a maximum noise figure of 0.462 dB at room
temperature and a return loss better than 10 dB from 300 MHz to 1.4 GHz. The technique demonstrates that
SiGe heterojunction bipolar transistors can be used for cost-effective applications in radio astronomy.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-27602017-08-31hb2016Carl and Emily Fuchs Institute for Micro-electronics (CEFIM)Electrical, Electronic and Computer Engineerin
Multi-band CPW fed MIMO antenna for bluetooth, WLAN, and WiMAX applications

In this letter, multi-band coplanar waveguide (CPW) fed multiple-input-multiple-output (MIMO) antenna is presented for Bluetooth, WLAN and WiMAX applications. The elements of MIMO antenna are identical CPW-fed printed monopole antennas whose bandwidth performances are improved by employing inverse U and meander line slots. In the design of the antennas, a low-cost FR4 substrate is used and the size of the element antennas are optimized as 35 mm x 30 mm. According to the measurements, S11 is below −10 dB in 2.38 GHz – 2.52 GHz and 3.19 GHz – 6.44 GHz bands with 0.2 dB and 2.9 dB average peak realized gains, respectively. The element antennas are placed orthogonally and fed independently to obtain MIMO structure whose size is optimized as 42 mm x 62 mm. The performance of MIMO antenna is also examined in terms of diversity parameters such as envelope correlation coefficient and apparent diversity gain, which are lower than 0.02 and higher than 9.9 in the operating bands, respectively
Wideband antenna for 4G MIMO applications

A small, wideband, multiple-input-multiple-output antenna
is presented for 4G long term evolution (LTE) applications. The proposed
antenna consists of a vertically polarized wideband stepped slot,
as well as a horizontally polarized narrowband, uniform slot, integrated
on a single substrate and fed by two ports. A prototype of the proposed
antenna was designed, fabricated, and measured. The stepped slot antenna
achieves an enhanced bandwidth of 122% from 0.77 GHz to
3.12 GHz, covering the 2G, 3G, and 4G bands. The narrowband slot
achieves a bandwidth of 35% from 2.11 GHz to 3.01 GHz, covering the
4G band frequencies only. The isolation between the two slots is greater
than 21 dB over the entire band of interest. The radiation pattern of the
wideband slot in the horizontal plane is omnidirectional in nature while
the narrowband slot exhibits a bidirectional radiation pattern in the horizontal
plane. The proposed antenna is suitable for indoor, ceilingmount,
microcell 4G LTE applications.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-27602018-03-31hb2017Electrical, Electronic and Computer Engineerin
A dual-band polarization independent FSS having a transparent substrate for ISM and Wi-Fi shielding

This paper presents a dual-band, polarization independent FSS for ISM and Wi-Fi shielding. The proposed structure has a band-stop characteristic for 2.5 and 5.1 GHz with a fractional bandwidth of 42% and 7%, respectively. The substrate of the FSS is a transparent material having a permittivity value of 2.77 and a thickness value of 1.48 mm, which provides band-pass characteristics for visible spectrum. The design, fabrication, and measurement of FSS were conducted for TM and TE polarizations; and satisfactory agreement was obtained
Dual port disc monopole antenna for wide-band MIMO-based wireless applications

In this article, design and implementation of a wide-band dual port monopole antenna based on single circular disc radiating element has been presented for Multi Input Multi Output (MIMO) configured 4G mobile and wireless communication systems. The proposed antenna uses a partial ground plane with two rectangular grooves which lie exactly below the respective 50 microstrip feeding lines in order to obtain enhanced antenna's impedance bandwidth of 2-6 GHz. A circular cut with 14 mm radius and centered at intersection of two partial rectangular ground planes is etched to reduce port to port RF coupling. The implemented dual port monopole antenna on 1.575 mm thick RT/Duroid 5880 substrate (with =2.2, tangent loss=.001) provides >15 dB RF interport isolation for antenna's 10 dB impedance bandwidth of 2-6 GHz with measured gain variations of 2-6 dBi for each port excitation. In addition to interport isolation measurement for dual port antenna, the envelope correlation coefficient over the required frequency range has been calculated and plotted using S-11, S-22, and S-21 measurement results to endorse the performance of dual port implemented antenna for diversity applications
Optically transparent frequency selective surface for ultrawideband applications

A multilayer ultra-wideband frequency selective surface (FSS), which filters the frequency range between 3.38 and 4.66GHz is presented. The proposed structure having a transparent substrate allows the light pass through itself, while it filters the electromagnetic waves at the frequency band of interest; and it has a bandwidth of 1.28 GHz. For the FSS structure, a transparency level of 52.5% obtained with a fractional bandwidth value of 32%. The structure is examined layer by layer; and the proposed FSS structures are evaluated in terms of bandwidth and transparency level
Automated target tracking in kilovoltage images using dynamic templates
  of fiducial marker clusters

Purpose: Implanted fiducial markers are often used in radiotherapy to
facilitate accurate visualization and localization of tumors. Typically, such
markers are used to aid daily patient positioning and to verify the target's
position during treatment. This work introduces a novel, automated method for
identifying fiducial markers in planar x-ray imaging.
  Methods: In brief, the method consists of automated filtration and
reconstruction steps that generate 3D templates of marker positions. The
normalized cross-correlation was the used to identify fiducial markers in
projection images. To quantify the accuracy of the technique, a phantom study
was performed. 75 pre-treatment CBCT scans of 15 pancreatic cancer patients
were analyzed to test the automated technique under real life conditions,
including several challenging scenarios for tracking fiducial markers.
  Results: In phantom and patient studies, the method automatically tracked
visible marker clusters in 100% of projection images. For scans in which a
phantom exhibited 0D, 1D, and 3D motion, the automated technique showed median
errors of 39 $\mu$m, 53 $\mu$m, and 93 $\mu$m, respectively. Human precision
was worse in comparison. Automated tracking was performed accurately despite
the presence of other metallic objects. Additionally, transient differences in
the cross-correlation score identified instances where markers disappeared from
view.
  Conclusions: A novel, automated method for producing dynamic templates of
fiducial marker clusters has been developed. Production of these templates
automatically provides measurements of tumor motion that occurred during the
CBCT scan that was used to produce them. Additionally, using these templates
with intra-fractional images could potentially allow for more robust real-time
target tracking in radiotherapy.Comment: 12 pages, 7 figure
Explicit optimization of plan quality measures in intensity-modulated
  radiation therapy treatment planning

Conventional planning objectives in optimization of intensity-modulated
radiotherapy treatment (IMRT) plans are designed to minimize the violation of
dose-volume histogram (DVH) thresholds using penalty functions. Although
successful in guiding the DVH curve towards these thresholds, conventional
planning objectives offer limited control of the individual points on the DVH
curve (doses-at-volume) used to evaluate plan quality. In this study, we
abandon the usual penalty-function framework and propose planning objectives
that more explicitly relate to DVH statistics. The proposed planning objectives
are based on mean-tail-dose, resulting in convex optimization. We also
demonstrate how to adapt a standard optimization method to the proposed
formulation in order to obtain a substantial reduction in computational cost.
  We investigate the potential of the proposed planning objectives as tools for
optimizing DVH statistics through juxtaposition with the conventional planning
objectives on two patient cases. Sets of treatment plans with differently
balanced planning objectives are generated using either the proposed or the
conventional approach. Dominance in the sense of better distributed
doses-at-volume is observed in plans optimized within the proposed framework,
indicating that the DVH statistics are better optimized and more efficiently
balanced using the proposed planning objectives
Automatic Liver Lesion Segmentation Using A Deep Convolutional Neural
  Network Method

Liver lesion segmentation is an important step for liver cancer diagnosis,
treatment planning and treatment evaluation. LiTS (Liver Tumor Segmentation
Challenge) provides a common testbed for comparing different automatic liver
lesion segmentation methods. We participate in this challenge by developing a
deep convolutional neural network (DCNN) method. The particular DCNN model
works in 2.5D in that it takes a stack of adjacent slices as input and produces
the segmentation map corresponding to the center slice. The model has 32 layers
in total and makes use of both long range concatenation connections of U-Net
[1] and short-range residual connections from ResNet [2]. The model was trained
using the 130 LiTS training datasets and achieved an average Dice score of 0.67
when evaluated on the 70 test CT scans, which ranked first for the LiTS
challenge at the time of the ISBI 2017 conference.Comment: Submission for ISBI'2017 LiTS Challenge ISIC201
Towards Robust Adaptive Radiation Therapy Strategies

The authors propose robust adaptive strategies based on stochastic minimax
optimization for a series of simulated treatments on a one-dimensional patient
phantom. The plan applied during the first fractions should be able to handle
anticipated systematic and random errors. At scheduled fractions, the impact of
the measured errors on the delivered dose distribution is evaluated. For a
patient receiving a dose that does not satisfy clinical goals, the plan is
reoptimized based on these individually measured errors. The adapted plan is
then applied during subsequent fractions until a new scheduled adaptation
becomes necessary. In the first adaptive strategy, the measured systematic and
random error scenarios and their assigned probabilities are updated to guide
the robust reoptimization. In the second strategy, the grade of
conservativeness is adapted in response to the measured dose delivery errors.
In the third strategy, the uncertainty margins around the target are
recalculated based on the measured errors. The simulated systematic and random
errors are either similar to the anticipated errors or unpredictably larger, in
order to critically evaluate the performance of the adaptive strategies. The
simulations show that robustly optimized treatment plans provide sufficient
treatment quality for those treatment error scenarios similar to the
anticipated error scenarios. Combining robust planning with adaptation leads to
improved OAR protection. In case of unpredictably larger treatment errors, the
first strategy performs best at improving treatment quality in terms of target
coverage and OAR protection. According to the simulations, these robust
adaptive treatment strategies are able to identify candidates for an adaptive
treatment, thus giving the opportunity to provide individualized plans, and
improve their treatment quality through adaptation
Methodological accuracy of image-based electron-density assessment using
  dual-energy computed tomography

Purpose: Electron density is the most important tissue property influencing
photon and ion dose distributions in radiotherapy patients. Dual-energy
computed tomography (DECT) enables the determination of electron density by
combining the information on photon attenuation obtained at two different tube
voltages. Most algorithms suggested so far use the CT numbers provided after
image reconstruction as input parameters, i.e. are imaged-based. To explore the
accuracy that can be achieved with these approaches, we quantify the intrinsic
methodological and calibration uncertainty of the seemingly simplest approach.Comment: 20 pages, 3 figures, 2 tables, pre-peer reviewed version, accepted by
  Medical Physic