The method for detecting magnetic fields based on magnetic fluid (MF) and fiber bundle was successfully demonstrated. The sensor works by measuring changes in the refractive index of MF due to changes in magnetic fields. Using MF with a concentration of 2.5%, the proposed sensor successfully detected a magnetic field in the range of 25.3 to 83.5 mT with a resolution of 3.3 mT.

A nonuniform current spreading in the current spreader layer greatly reduced the internal quantum efficiency (IQE) of the light‐emitting diodes (LED). The effects of the current spreading layer on the electrode contact area toward the IQE in a vertical design of gallium nitride (GaN)‐based LED chip is analytically analyzed. The contact area was varied by changing the value of the electrode's width

A novel two‐dimensional crest factor reduction (2D‐CFR) is proposed to improve the dual‐band concurrent performance of power amplifiers (PAs). The concurrent performance of target PA can be improved significantly when the power for peak detection conforms to the concurrent characteristic. Peak detection and clipping operation are presented based on concurrent output capacity of PAs, which can be efficiently

Herein, an extremely low‐profile and wideband array antenna is proposed whose height is 0.03 λlow at the lowest operating frequency. The development of the proposed array antenna is described, and its performance is compared with those of conventional patch arrays, stacked patch arrays, planar ultrawideband modular antenna arrays, and tightly coupled dipole arrays (TCDAs). Furthermore, the impedance

The main problem of dual‐band bandpass filter (BPF) structures is to control each passband performance individually, separately, and independently. This Letter is proposed a dual‐band BPF based on a source‐load coupling structure with stub‐block isolation to overcome the problem. The lower band resonator structure is placed on the top side, while the upper band resonator is placed at the bottom side

A low‐profile planar phased array based on the hybrid‐mode patch technique is presented to achieve the goal of increasing the scanning angle. The array element antenna simultaneously operates at TM10 and TM20 modes of two rectangle patches. By adjusting the length of a slot etched on one patch, the far field of the two modes can be combined by a certain proportion, and thus the complementary beams

A high‐gain dual‐band electromagnetic band‐gap (EBG) resonator antenna (ERA) which is suitable for 60 GHz short‐range communication and 77 GHz vehicle collision avoidance application is proposed. The EBG is constructed by two identical slabs over a fully reflective ground plane. A dipole in Taiwan Semiconductor Manufacturing Company (TSMC) 65 nm process is employed to serve as a feeder of the resonator

The time‐domain finite‐element method (TDFEM) is extended to study the two‐dimensional transient electromagnetic scattering from multiple targets above a rough surface in this article. The perfectly matched layer is employed as the truncation boundary of TDFEM region to absorb the outward wave scattered from the model. To introduce the incident wave, a total field boundary, which splits the whole region

This paper presents the design of a unique “corporate feed‐microstrip filtenna array” to be used as “radiating antenna” of a wireless system. The filtenna is a basic patch antenna fed by 50 Ohms microstrip line, loaded with complementary split ring resonators (CSRRs). When the basic patch antenna is made to resonate at 1.8 GHz, it also introduces unwanted spurious radiations appear at 2.82 and 3.46 GHz

In this article, a dual‐band sixth order double symmetric T‐slot filter is proposed for the 5G communication systems. This filter contains two duplicate square resonators and a T‐shape feedline on the Rogers RT duroid 5880 substrate. Operating at the 28 and 38.5 GHz frequencies from licensed 5G frequency bands and small size make this filter appropriate for different 5G applications. Furthermore, an

A graphene‐metamaterial hybrid structure for the design of reconfigurable low pass filters in terahertz region is proposed. This design manages to manipulate the resonance characteristics of metamaterial and terahertz wave response characteristics of the hybrid structure by controlling the chemical potential of graphene. The shift of the resonant frequency and the modulation of the resonant peak of

A superstrate loaded body implantable microstrip patch antenna working on Medical Implant Communications Service (MICS) (402‐405 MHz) band for biotelemetry applications is proposed. A 0.64‐mm thick high‐dielectric material Rogers RO Duroid 3010 is used both as substrate and superstrate of dielectric constant 10.2. Shorting pin is used to make compact antenna with footprint of 13.3 × 14.6 mm2. Appreciable

A low‐profile wideband planar phased array, working in X band and with two‐dimensional (2‐D) beam scanning characteristic is presented. In order to meet the requirements of wideband 2‐D beam scanning and low‐profile performance, a cavity‐backed slot stacked microstrip element is introduced. The array element is mainly composed of the open‐ended microstrip line printed on the bottom substrate, which

This paper presents an ultra‐wideband, high‐efficiency continuous resistive‐reactive class‐J power amplifier. The design space is extended by controlling the second harmonic with impedance component and multiple harmonics of a continuous class‐J PA, enabling it to achieve efficient output in multiple octave bandwidths. Based on this theory, a GaN HEMT transistor CGH40010F is used to achieve a 0.6 to

This article presents a high gain cavity‐backed slot antenna using a perfect magnetic conductor (PMC) ground plane and multilayered superstrates. A textured surface of periodic pins is applied to realize a high impedance surface (HIS), which simulates a PMC ground plane. The main advantage of using this structure is to suppress the surface wave propagation, improve the input impedance matching, increase

This paper presents the design and characterization of two tunable power detectors, based on PN diodes, integrated in SiGe 55‐nm BiCMOS technology from ST‐Microelectronics. The working frequency band of the circuits is (35‐50) GHz dedicated for 5G applications. The detector parameters are adjusted by controlling the biasing current, this characteristic makes them suitable to be utilized in different

A novel planar elliptic function lowpass filter (LPF) based on substrate integrated suspended line technology is developed and investigated. Transformed radial stub, stepped‐impedance resonators, and open stubs are cascaded to obtain sharp roll‐off and wide stopband. The proposed LPF produces six transmission zeros in the stopband, and the mechanism of the transmission zeros is studied. Both the simulation

High energy, high repetition rates laser with excellent beam quality are fundamental components for LiDAR. In particular, high pulse energy is benefit for long distance range imaging. Narrow pulse width and high repetition rates are benefit for high resolution and high refresh rate operation of LiDAR. However, increasing the laser repetition rates will cause the pulse energy decreasing and the pulse

We propose and experimentally demonstrate a temperature sensor based on a suspended‐core microstructure optical fiber (SCMF). The sensor is constructed by fusion splicing a piece of SCMF between two up‐tapers which act as light beam couplers. The Mach‐Zehnder interference (MZI) is formed by the silica core modes and the air cladding modes in the SCMF. The sensitivity of −0.011 rad/°C in the temperature

The effective clinical management of cancer is entirely dependent on the detection at a suitable early time as well as on the proper diagnosis. The main aim of this review is to survey the applications of dielectric spectroscopy in the clinical cancer diagnosis and distinguishing between normal and tumor tissues. This review focuses on the recognition of the biophysical properties of normal and malignant

In current scenario, the communication is essentially depends on the design consideration and working principle of an antenna. The design consideration antenna maybe a large size or small size, but it will develop in various ranges for more applications. In previous antenna’s having a problem on design considerations like frequency and materials. In this paper presents the particle swarm optimization

In order to constantly and accurately recognize and track flying targets, using the infrared photoelectric detection system, while scientifically analyze the detection capability of the system, in complex background environments. This paper analyzes the measurement principle of the infrared photoelectric detection system, establishes a radiation energy calculation model of the background and the optical

Two kinds of triple‐band filters based on 900 sector substrate integrated waveguide (SSIW) are firstly investigated. The resonant frequencies of SSIW are deduced by analogy with a circular SIW cavity. By contrast, SSIW cavity is not only easier to suppress higher‐order modes than the circular SIW cavity, but also easier to cascade multiple cavities. Two kinds of miniaturization filters are realized

This communication focuses on the Raman spectroscopic characterization of a voltage‐controlled electrospray deposition (VCED) of multiwalled carbon nanotubes (MWCNTs) dispersed from acid refluxed and SDBS (sodium dodecyl benzene sulfonate) assisted carbon nanotube (CNT) dispersion techniques. This versatile method resulted in the direct deposition of CNT films on the surface functionalized target substrates

This article presents a practical design methodology to construct output matching networks for broadband continuous mode monolithic microwave integrated circuit (MMIC) power amplifiers (PAs). Unlike conventional harmonic manipulation approaches, combinations of parallel and series LC resonant circuits are utilized to build the matching networks as it can generate frequency‐dependent components and

In this letter, a compact tri‐notched wideband bandpass filter based on stub‐loaded ring resonator (SLRR) and shorted stub‐loaded stepped impedance resonators (SSLSIR) with wide upper stopband is presented. The wideband characteristic is excited by coupling SLRR and SSLSIR with the arrangement of defected ground structures on the back of the substrate. By placing two sets of SSLSIRs inside and outside

In the current study, we have considered the induced phase transitions in Al/InSe thin film substrates and employing them for fabrication of InSe/Cu2O tunneling channels. The InSe substrates are observed to prefer the transition from the hexagonal γ‐In2Se3 to the rarely observed tetragonal InSe. The phase transitions are obtained by the thermally assisted diffusion of aluminum, which was already kept

This paper reports a gas and humidity sensor design with improved sensitivity. The design is based on a planar antenna loaded with carbon nanotubes (CNTs). Sensing is achieved by the conductivity change of the CNT film when exposed to various gases or humidity levels. The sensitivity improvement was achieved by replacing a portion of the patch conductor at the dominant edge with a strip of CNT film

This article presents an inductorless wideband balun low noise amplifier (LNA), which uses noise reduction and linearity optimization techniques at low supply voltages. The proposed self forward body biased LNA uses inverter type amplifier structure as input stage for impedance matching while output stages are noise reduction stages, which partially cancel the noise of the input stage. In addition

When the broadband impedance matching techniques are applied to the Wilkinson power divider, it operates in a larger frequency range and covers many communication bands. In this study, an ultra‐wideband (UWB) multisection Wilkinson power divider (WPD) circuit has been designed. Euler method has applied to the circuit that had equal power dividing feature on its two output ways. In the three‐section

A novel design of horizontally polarized end‐fire antenna array with a complete ground (GND) for the fifth‐generation (5G) millimeter wave (mmWave) applications is proposed in this article. The antenna employs four dielectric layers with the relative permittivity successively increasing from top to bottom. Utilizing the refraction of the radiated waves between different dielectric layers, the uptilting

In this letter, a dual band circularly polarized (CP) meta‐structured antenna is designed by −1 mode for L1 band and mu‐zero resonance mode for L2 band, respectively. The antenna consists of two kinds of unit cells which have four unit elements for −1 mode and mu‐zero resonance mode, respectively, in order to utilize the limited space efficiently, and to maximize the gain. Since two modes of −1 mode

A wide‐angle frequency scanning narrow‐wall slotted waveguide array antenna with monopulse function is designed for two‐dimensional electrical scanning radar and communication systems. A novel slow wave waveguide formed by loading the periodic metal T‐shaped sheets onto the narrow wall is used to enhance the frequency scanning angular sector of the edge‐slotted waveguide traveling wave array. Two slotted

In this paper, we propose a slot antenna with circularly polarized (CP) characteristics in two frequency bands. The proposed antenna consists of a square wide slot with a square patch in the center and a pair of stubs for radiator asymmetry. The proposed antenna shows right‐hand CP characteristics at 1.88 GHz and left‐hand CP characteristics at 4.41 GHz. The proposed antenna has measured impedance

A compact two‐element multiple‐input multiple‐output (MIMO) antenna is proposed for triple‐band applications with very high port isolation. The structure is constructed in‐house with a flexible biomass material which is coconut husk. Two metallic “8”‐shaped antenna structures are employed manually on the substrate to serve as MIMO elements. Frequency bands of the antenna for (S11 ≤ −10 dB) are obtained

In this article, a compact super wideband (SWB) high bandwidth dimension ratio (BDR) steering‐shaped antenna is proposed for future wireless communication applications. The proposed antenna consists of a linearly tapered microstrip‐fed circular ring with four elliptical spokes to connect with a central circular disk to form a steering‐shaped radiating patch and a rounded cornered notch‐loaded rectangular

In this paper, a novel compact microstrip patch antenna with a boresight filtering gain response is proposed. The proposed antenna consists of a radiating patch, a ground plane, two pairs of slots respectively etched on the radiating patch and the ground plane, two shorted vias connecting the radiating patch and the ground plane. The slots on the ground plane not only provide a gain null in the lower

Considering the increasingly wide application of optical fiber sensors, this article aims to present an alternative form of interrogation without the use of an optical spectrum analyzer or any other high‐cost devices. The sensor studied here is a long‐period grating being used to measure temperature. The interrogator is composed of optical filters and photodetectors whose responses are processed by

In this article, a fiber‐optic sensing scheme based on Stimulated Brillouin scattering effect in a recirculating fiber ring and frequency down‐conversion is proposed and experimentally demonstrated. By employing the recirculating fiber ring structure, high‐order backscattering Stocks light has been generated. The Brillouin frequency shift will be affected by the environmental variations, such as, temperature

This letter proposes a newly designed differentially fed dual‐band circularly polarized (CP) printed slot antenna (PSA). The antenna consists of two oppositely fed halberd‐shaped strips and an S‐shaped slot. By configuring the antenna structure in rotationally symmetric fashion, the fields radiated by any two rotationally symmetric parts of the CP PSA will be constructive when excited differentially

In this letter, a 3‐D optimized one‐step leapfrog weakly conditional stability finite‐difference time‐domain (WCS‐FDTD) scheme, which introduces the artificial anisotropy parameters into the one‐step leapfrog WCS‐FDTD scheme, is proposed to suppress the numerical dispersion error and boost the accuracy without the enhancement of the simulation complexity. The proposed scheme maintains the property

This letter presents a wide‐band 2:1 injection‐locked frequency divider (ILFD) in the 0.18 μm BiCMOS process with circuit model of class‐AB. The ILFD uses an 8‐shaped inductor in shunt with parasitic capacitors as the resonator, and it also employs two capacitive cross‐coupled pairs to generate negative resistance for oscillation. The gate biases of capacitive cross‐coupled pairs are fully utilized

This paper presents a coaxial resonator for dielectric measurements of low and medium loss liquids at multiple resonance frequencies up to 8 GHz with the fundamental transverse electromagnetic (TEM) resonant mode at 2 GHz. The measurement is by filling the entire resonator cavity with the material under test and the permittivity of the material is readily extracted using simple equations. This technique

A compact flexible fractal ultra‐wideband antenna with band notch characteristic is presented. The antenna is printed on a 12.5 μm flexible polyimide substrate, and an impedance bandwidth of 15.48 GHz (3.6‐19.08 GHz) is achieved along with an overall antenna size of 20.5 × 13.9 mm2. The design of the hexagonal radiator in the fourth iteration effectively enhances the impedance bandwidth of the antenna

A selectivity‐enhancement technique is presented for design of parallel‐coupled stepped‐impedance resonator (SIR) based dual‐band bandpass filter (BPF) in this article. The presented dual‐band BPF consists of two short‐circuited coupled lines (SCCLs) and a couple of parallel‐coupled SIRs. Theoretical analysis and numerical simulations on the proposed parallel‐coupled dual‐band BPF and SCCLs are implemented

In this paper, the results of numerical investigation of a metal photonic band gap cavity are presented. The investigated resonator is dual‐gap and is considered as an intermediate for the K‐band multibeam klystron. A working mode is a 2n mode with a frequency of 24.15 GHz. Electrodynamic characteristics of the cavity (characteristic impendance, beam coupling factor, relative electronic conductivity

This work demonstrated the directional passive intermodulation (PIM) product distribution effect in a microwave two‐port network using a distributed nonlinear model. The analysis is demonstrated through the comparison of PIM products at the double ends of a general two‐port network by a microstrip line. The reverse and forward PIM products are compared with the nonlinear source distribution and carrier

In this paper, a new type of microwave microfluidic sensor is presented, using three separate half wave microstrip resonators with a common junction. The sensor comprises three parallel resonators with resonant frequencies of 2.5, 3.5, and 4.5 GHz. This sensor exhibits all the usual advantages of microwave resonant methods for dielectric liquid characterization, such as high precision, accuracy, and

A technique for the reduction of third‐order intermodulation distortion (IMD3) occurring in bulk acoustic wave (BAW) filters and multiplexers is presented. The method consists of using the intrinsic second‐order intermodulation distortion generated by BAW filters and multiplexers themselves by injecting an externally controlled amplitude and phase modulated signal at low frequency to compensate for

A novel dielectric waveguide filter based on isosceles right‐angled triangular (RAT) resonators is presented in this letter. By connecting the vertices of four isosceles RAT waveguide cavities, a square fourth‐order cross‐coupled waveguide bandpass filter is formed. The presented filter uses the partition wall and shallow blind hole to realize positive coupling and the deep blind hole to realize negative

In this article, two Ka‐band (26.5‐40 GHz) waveguide attenuators designed for three‐dimensional (3‐D) metal printing are presented. These designs are based on long waveguides with elliptical cross‐sections, so that the waveguide structure can be self‐supported during printing. Bended waveguide and helical waveguide are utilized by the two attenuators, respectively, to achieve reduced overall sizes

In this work, 2‐element slot‐based frequency reconfigurable (FR) multiple‐input‐multiple‐output (MIMO) antenna design antenna with a very wide‐sweep is proposed for dynamic spectrum sharing (DSS) in 5G technologies. FR is achieved using varactor diode with frequency tuning range from 1655 to 2605 MHz. The design is a low profile with planar structure having a single element footprint of 19.5 × 20 mm2

Free‐space optics (FSO) is a perfect line of sight communication which is gaining a lot of popularity in the current research as it offers many advantages such as license free communication, high bandwidth, high speed, low bit error rate, and so on. Like the other communication technologies, FSO also suffers from adverse effects due to the climatic changes in the atmosphere. Some of the prominent effects

GaN/Al0.5Ga0.5N and InN/Al0.5Ga0.5N as a III‐nitride quantum dot semiconductor optical amplifiers (QD‐SOAs) are studied in detail in this paper. The optical gain, spontaneous emission rate, and lineshape function are calculated using non‐Markovian relaxation compared with Markovian one. Gain is then connected with the rate equations model to obtain a dB gain, output power, and shot noise in these SOAs

In this article, an efficient interpolation‐free algorithm (IFA) applied for cylindrical millimeter‐wave (MMW) holographic three‐dimensional (3‐D) reconstruction is proposed. Compared with previous cylindrical MMW holographic 3‐D reconstruction methods, the proposed IFA can efficiently achieve high‐quality 3‐D reconstruction within the region of interest (ROI). In the IFA, the spherical wave data are

A front‐to‐back pattern‐reconfigurable circularly polarized (CP) antenna based on two pairs of planar complementary dipoles with back‐to‐back configuration is presented and implemented. The 8 p‐i‐n diodes are employed into the front and back printed dipole arms. The beam direction can be switched from front‐to‐back, and the left‐right circular polarization can also be changed at each beam direction

A novel wideband dual‐circularly polarized orbital angular momentum (OAM) antenna array using metasurface is proposed. The proposed antenna array composed of four antenna elements generates OAM beams in a simple configuration. Each antenna element is placed perpendicularly to the adjacent one, and fed by an in‐phase excitation with equal amplitude. Each antenna element is based on corner‐truncated

We propose a novel probabilistically shaped amplitude and pulse position modulation (APPM) based on stepped amplitude probability distribution for optical access networks. By adopting the probabilistic shaping (PS) technique, average signal power can be reduced and better bit error rate (BER) performance obtained. The proposed PS‐APPM scheme has been successfully verified in a 25‐km standard single‐mode

This paper presents a performance analysis of different microcantilever shapes integrated with the optical MEMS system in different fluid mediums. Microcantilevers such as rectangular, trapezoidal, and triangle profile are coupled with optical sensing layers. Here, the concept of integration of optical sensing layer with different shapes of microcantilever is novel. The cantilever is designed and developed

This paper presents theoretical analysis and design procedures for low noise amplifiers (LNAs) in advanced CMOS technologies. For demonstration, a 30‐GHz LNA designed for 5G millimeter‐wave communication systems was fabricated in a 65‐nm CMOS process. It provides a power gain of 22.6 dB with a noise figure of 3.2 dB while drawing 7.3 mW from a 1.2 V supply.