A computationally efficient global optimization method, the differential evolution algorithm (DEA), is proposed for synthesis of uniform amplitude arrays two classes, i.e., unequally spaced with equal phases and unequal phases. Phase-only uniformly exited (position only synthesis) are compared it seen that, by using spacing, number array elements can be significantly reduced attaining sidelobe levels. From DEA-based amplitudes phases, found that a tradeoff exists between size range same...

We present a 2.4 GHz unbalanced loop antenna that can be stretched along multiple dimensions simultaneously. It was realized by incorporating room temperature liquid metal alloy into microstructured channels in an elastic material. The demonstrated prototype exhibits stretchability of up to 40% two orthogonal orientations as well foldability and twistability. Port impedance radiation characteristics the nonstretched were studied numerically experimentally. Measured results indicate...

A mechanically flexible planar inverted cone antenna (PICA) for ultrawideband (UWB) applications is presented. It can be both folded and stretched significantly without permanent damage or loss of electrical functionality. The manufactured with a process in which conductors are realized by injecting room temperature liquid metal alloy into micro-structured channels an elastic dielectric material. material together the enables bending very small radius, twisting, stretching along any...

Background Medicinal plant trade is important for local livelihoods. However, many medicinal plants are difficult to identify when they sold as roots, powders or bark. DNA barcoding involves using a short, agreed-upon region of genome unique identifier species– ideally, global standard. Research Question What the functionality, efficacy and accuracy use identifying root material, roots by herbalists in Marrakech, Morocco, test dataset. Methodology In total, 111 samples were sequenced four...

A new device, the quantum-barrier-varactor diode (QBV diode), is proposed for use in multipliers millimetre waves. Since capacitance/voltage characteristic symmetric, only odd harmonics are obtained. Hence there no idler circuit to consider tripler and one quintupler. It shown that triplers quintuplers, theoretical efficiency using QBVs comparable or possibly larger than Schottky varactor diodes.

A novel ultrawideband (UWB) printed wide-slot antenna is presented. The design based on the planar inverted cone (PICA), introduced by Suh. presented comprises PICA-like structures, etched from a double-layer substrate. Compared to original PICA, it lower in profile, more compact and maintains comparable performance. prototype integrated circuit board fed microstrip line fabricated measured. results show that proposed provides at least 13:1 impedance bandwidth 10-dB return loss.

Improved heat dissipation in InP Gunn devices resulted RF power levels exceeding 200, 130, 80, and 25 mW at oscillation frequencies of around 103, 132, 152, 162 GHz, respectively. Corresponding dc-to-RF conversion efficiencies exceeded 2.3% from 102 to 132 GHz. Power combining increased the available over 300 106 130 136 more than 125 152 GHz with corresponding 80% 100%. Operation a second harmonic mode yielded 3.5 214 2 220 as well 1 280, 300, 315 10 202 9 210 4 235 were obtained GaAs...

Most agricultural statistics are calculated per field, and it is well known that classification procedures for homogeneous objects produce better results than per-pixel classification. In this study, a multispectral segmentation method automated delineation of field boundaries in remotely sensed images presented. Edge information from gradient edge detector integrated with algorithm. The uses all available by adding the magnitudes directions edges derived detection single bands. addition...

Experimental results are presented using quantum-barrier-varactor (QBV) diodes in harmonic multipliers. Output powers and tripler conversion efficiencies of more than 2 mW 5%, respectively, were achieved between 210 280 GHz. In a crude experiment, an efficiency 0.2% for the fifth was measured at 310 The values QBV diode as comparable to state-of-the-art Schottky-varactor triplers. experimental agree well with theoretical calculations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...

The problem of classifying road vehicles according to vehicle type is considered. proposed solution based on using height and length profiles obtained by a microwave (MW) radar sensor. We show that if the sensor satisfies certain requirements, then precise feature vector can be extracted, simple deterministic algorithms applied determine class. Field trials spread-spectrum MW system operating these principles have been carried out. They confirm accurate classification large number classes reached

A detailed understanding of the different mechanisms being responsible for terahertz (THz) emission in ferromagnetic (FM) materials will aid designing efficient THz emitters. In this report, we present direct evidence from single layer Co[Formula: see text]Fe[Formula: text]B[Formula: text] (CoFeB) FM thin films. The dominant mechanism is anomalous Hall effect (AHE), which an a net backflow current created by spin polarized reflected at interfaces layer. AHE-based CoFeB emitter optimized...

The integration of K-band (20-40 GHz) full wavelength square wire- and slot-loop antennas on low resistivity (11-70 Omegacm) silicon substrates is addressed. By the use polymer or oxide/nitride membranes to support slot wire loop over micromachined trenches efficiency enhanced while majority bulk within aperture antenna preserved enable active devices. A 3.6times3.6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> large chip with 200...

A highly efficient microfluidic 3D electrically small antenna is created using a simple fabrication technique. It easy to construct simply by pneumatically inflating planar into spherical cap. has premium performance around its hemispherical shape, combining wide working band with high efficiency.

The human body can act as a medium for the transmission of electromagnetic waves in wireless sensor networks context. However, there are losses biological tissues due to presence water and salts. This Letter focuses on lateral intra-body microwave communication through different tissue layers demonstrates effect thicknesses by comparing signal coupling channel. For this work, authors utilise R-band frequencies since it overlaps industrial, scientific medical radio (ISM) band. channel model...

The integration of an on-chip folded dipole antenna with a monolithic 24-GHz receiver manufactured in 0.8-m SiGe HBT process is presented.A high-resistivity silicon substrate (1000 cm) used for the implemented circuit to improve efficiency integrated antenna.Crosstalk between and spiral inductors analyzed isolation techniques are described.The receiver, including receive optional transmit antenna, requires chip area 4.5 mm 2 provides 30-dB conversion gain at 24 GHz power consumption 960...

This letter demonstrates a 20-GHz radio frequency microelectromechanical system (RF MEMS)-based electrically switchable antenna on quartz substrate. Two quasi-Yagi elements are monolithically integrated with single-pole double-throw (SPDT) MEMS switch router network 21 mm times 8 chip. Electrical beam steering between two opposite directions is achieved using capacitive SPDT switches in the router. Port impedance and radiation patterns studied numerically experimentally. Measured results...

This paper explores high data rate microwave communication through fat tissue in order to address the wide bandwidth requirements of intrabody area networks. We have designed and carried out experiments on an IEEE 802.15.4-based WBAN prototype by measuring performance channel terms packet reception with respect length power transmission. proposes demonstrates a using phantom <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex-vivo</i>...

Abstract To achieve a large terahertz (THz) amplitude from spintronic THz emitter (STE), materials with 100% spin polarisation such as Co‐based Heusler compounds ferromagnetic layer are required. However, these known to loose their half‐metallicity in the ultrathin film regime, it is difficult L2 1 ordering, which has become bottleneck for growth. Here, successful deposition using room temperature DC sputtering of and B2 ordered phases Co 2 FeAl full compound reported. used together highly...

InP TED (transferred electron device) oscillators have been experimentally investigated for frequencies between 170 and 279 GHz. It has found that output powers of more than 7 0.2 mW are possible at 180 272 GHz using second- third-harmonic mode operation, respectively. Conversion efficiencies 13% 0.3% fundamental second harmonic third harmonic, respectively, found. The conversion comparable to GaAs TEDs. powers, efficiencies, tuning ranges (more 22%) the biggest reported TEDs these...

The design of electrically steerable traveling wave microstrip antenna arrays is presented. Varactor diode based phase shifters implemented on the same metallic layer as patch elements are used to provide a variable progressive shift in array. Two antennas for 5.8 GHz ISM band, manufactured single printed designs standard PTFE soft substrate, demonstrated. A ten-element beam-tilting vertical array using transmission type realized, yielding between 11.8 13.9 dBi gain 0deg 11deg beam tilt...

A quarter-wave transversal slot in the center of a handheld terminal ground plane is proposed and evaluated as wideband antenna for low profile mobile phones. By feeding with microstrip line, triple-resonance response obtained from chassis, stub interaction, providing sufficient impedance bandwidth radiation efficiency to cover 0.9-2.7 GHz frequency range. While introduction has many advantages over e.g. PIFA or patch structures, both terms performance cost, circuit floor planning becomes...

Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range resistances the measurement circuit around transistor than is possible when using voltage amplifier same kind measurements. The ac amplification factor h/sub fe/ and sum base emitter series (r/sub b/+r/sub e/) extracted from noise. It established that dominant source situated...

Theoretical work on single barrier varactor (SBV) diodes indicates that the efficiency of a tripler with SBV diode has maximum for considerably smaller capacitance variation than previously thought. based GaAs, InGaAs and InAs have been fabricated their DC properties tested. Detailed modeling carrier transport device is carried out in two steps. First, semiconductor equations are solved simultaneously, using finite difference scheme one dimension. Second, calculated I-V C-V characteristics...

A traveling-wave microstrip array antenna with circular polarization in presented. It uses a novel circularly polarized dual-feed radiating element. The element is square patch chamfered corner. fed by lines, so and feed lines can be realized single layer. five-element designed built. Measured performance