A new arrangement of optical frequency comb and its deployment in a wavelength division multiplexed optical network is proposed and demonstrated. The generated optical carriers are separated by a frequency spacing of 10GHz and the overall spectra comprise 63 individual optical carriers. These carriers are identified and separated by utilizing rectangle optical filters, and 10Gbps data is modulated

In this work, a novel symmetric periodic leaky-wave antenna is proposed for open stopband suppression. The unit cell of the proposed antenna consists of an H-shaped ring as the leakage element. Using L–C circuit analysis, it is shown that the open stopband is effectively eliminated by optimizing the H-shaped ring. A prototype is fabricated to verify the simulated results. The antenna radiates in the

This paper presents a novel miniaturized noninvasive submersible compact planar sensor to estimate petroleum contents for various industrial and remote sensing applications. The proposed sensor is based on a microstrip technique wherein a complementary split-ring resonator is used to sense samples under interrogation. The proposed compact sensor works at a resonating frequency of 8.87 GHz with quite

A metasurface is highly useful for improving the performance of patch antennas and reducing their size due to their inherent and unique electromagnetic properties. In this research work, we design a wideband bandstop reflector-based frequency selective surface (FSS). It consists of a periodic array of circular shape metallic rings with four stubs. The FSS unit cell resonates over a frequency band from

In this letter, an ultra-wide band bandstop filter (BSF) with three transmission zeros and one reflection zero is presented. The role of the circular etched shaped stub as a notch pass response is investigated. Further, a compact size of 13 mm × 24.30 mm (0.219λg× 0.410λg) is achieved by employing an interdigital capacitor to increase coupling between the lines. Furthermore, the transmission line model

In this paper, a center-fed four-way power divider with wideband harmonic suppression is proposed. A distinguishing feature is the use of sectorially modified Gielis curves (SMGCs) for open stubs, shorted stubs, and stub-loaded coupled-line structures, providing more degrees of freedom in the designs to suppress the wideband harmonics. The expressions for the SMGCs, along with the ABCD matrix elements

Ensuring the sharp roll-off property of a filtering antenna in many applications is regarded as one of the highest priorities and requires the designers' full concentration. This work devotes itself to challenge the remarkably roll-off characteristics by searching for the best fragment-type patterns etched on a ultrawideband monopole radiator without using any other auxiliary components or resonant

With the advancement in evolving concepts of software-defined networks and elastic-optical-network, the number of design parameters is growing dramatically, making the lightpath (LP) deployment more complex. Typically, worst-case assumptions are utilized to calculate the quality-of-transmission (QoT) with the provisioning of high-margin requirements. To this aim, precise and advanced estimation of

In this paper, a cascade asymmetrical metasurface (CAM) is proposed to generate the functionality of multiband spatial angular filtering transmissions. More specifically, dual-asymmetrical-C-slits printed on the CAM can readily tune the transmission frequencies by controlling the incident angles of electromagnetic waves. In the meanwhile, the CAM with multiple hierarchical structures would be capable

The aperture-coupled patch antenna integrated with the amorphous silicon solar cell based on the substrate-integrated suspended line platform is presented in this letter. The antenna patch on G1 layer is used as the cathode of amorphous silicon cell and the 1 × 2 array antenna is proposed based on the unit. The solar cell antenna operating from 4.67 to 5.17 GHz has the characteristic of high gain,

There are special requirements for the laser beam diameter and divergence angle in various optical combination systems, so most of the designs add beam expansion and contraction systems. Off-axis reflective systems are more widely used in practical applications because of their nonobstructing characteristics and unaffected by chromatic aberration. This paper designs an optical system with both beam

In contrast to existing antennas with polarization and directional characteristics, we propose a novel isotropic antenna that provides equivalent vertical and horizontal polarization in all directions. The final design was guided by simulations, with the performance characteristics of the fabricated antenna verified experimentally. In the proposed antenna, two λ/4 folded microstrip antennas were integrated

A multilayer substrate integrated waveguide (SIW) quasi-elliptic bandpass filter based on the printed circuit board (PCB) process is presented for millimeter-wave applications in this article. The proposed filter consists of four SIW cavities, in which the upper and lower cavities form the vertical couplings, and the two lower cavities form a mixed coupling by a short-ended conducting strip and metallized

In this article, a novel design methodology of a half-mode substrate integrated waveguide (HM-SIW) filtering Wilkinson power divider is proposed. The width between the two metallic rows of vias in the conventional HM-SIW divider is governed by a truncated Fourier series expansion to obtain specific passband/stopband performance. The optimized varying width is obtained using the even-mode analysis,

This article presents a dual-beam dual-mode circularly polarized (CP) antenna based on substrate integrated waveguide (SIW) technology. The antenna is etched with an octagon slot on upper surface of a SIW rectangular cavity, which has size of 1.4 λ g × 1.4 λ g . Four square patches with the same size and a cross-shaped patch are placed in the slot. Experiments are conducted both on simulation and measurement

This letter proposes an end-fire Vivaldi antenna based on spoof surface plasmon polaritons (SPPs). SPP is generated by a periodic corrugated metal–insulator–metal (CMIM) waveguide on which the odd mode of the SPP is propagated and is rarely used in the design of antenna transmission lines. Gradient corrugations and slotlines form the transitional part to achieve momentum matching and impedance matching

A metasurface (MS) antenna for the 5 GHz wireless local area network (WLAN) band is presented in this paper. The antenna is feed by a modified aperture-coupled structure with an optimized rectangular nonuniform MS to widen the bandwidth and improve the gain. The proposed antenna has a thickness of 4 mm and occupies an area of 50 mm × 50 mm. The operating frequency range of the antenna is 4.72–6.19 GHz

In this paper, a balanced tri-band band-pass filter (BPF) with the third independently tunable passband and the other two fixed ones based on a novel multi-stub loaded resonator (MSLR) is presented. Due to the symmetrical circuit structure, the even-and odd-mode methods are applied to analyze the differential-mode (DM) and the common-mode equivalent circuits of the proposed resonator, and the correspondingly

This article reports a compact microstrip dual-band bandpass filter (DBBPF) using two pairs of λ/4 short-circuited stepped impedance resonators (SSIRs) and a stub-loaded triple-mode resonator (STR). The first and fourth λ/4 SSIRs not only couple with the second and third SSIRs to form the lower passband, but also serve as the feeding structure and provide source-load coupling for the higher passband

A low-loss bandpass filter with a nonresonant node (NRN) based air-filled substrate integrated waveguide (SIW) is proposed in this study. It is based on a second-order inductive diaphragm-coupled filter with an additional NRN to introduce a transmission zero (TZ) in the upper stopband. Measured results show that the filter has a center frequency of 32.27 GHz with the bandwidth of 0.9 GHz. The insertion

In this article, a novel left-handed (LH) waveguide transmission line with good filtering performance is proposed and implemented below the TM mode cutoff frequency. TM11 mode is employed and transmitted inside the waveguide. The LH passband is achieved by TM mode cutoff operation and complementary split-ring resonator (CSRR) loading, which are able to provide negative μ and ε, respectively. It constitutes

In this article, a temperature-sensing scheme by using a microwave photonics filter (MPF) based on an actively mode-locked fiber laser (MLFL) has been proposed and experimentally demonstrated. The MPF is formed by the MLFL and a photodetector (PD). Single-mode fibers with different lengths in the laser cavity acts as the sensing head. The experimental results show good linearity between the frequency

In this article, we have proposed and demonstrated a sensing interrogation scheme of microwave photonic filter (MPF) based on multi-wavelength fiber laser (MWFL). A Mach-Zehnder interferometer (FMZI) acts as the wavelength selective component in the laser cavity as well as the sensing element. An erbium doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) are employed as hybrid

The paper presents the design of a combined antenna, optimized in numerical calculations to radiate high-power bipolar pulses with a duration of 0.5 ns. According to the results of the calculations, a compact antenna with the dimensions of 60 × 65 × 55 mm3 (width × height × length) was made. The influence of a high-voltage insulator position relative to the antenna input on the matching band of the

A capsule endoscope transmits images of the digestive organs from the inside to the outside of the body. For in-to-out body transmission, a capsule endoscope can use human body communication (HBC) instead of radio frequency (RF). However, an HBC endoscope does not transmit in the opposite direction (i.e., out-to-in body transmission). In this study, out-to-in body transmission using HBC at 13.56 MHz

In this article, we proposed a novel circularly polarized magnetoelectric (ME) dipole antenna with low profile, which is excited by substrate integrated waveguide aperture-coupled feeding structure with a butterfly-shaped slot. The ME dipole antenna is formed of a couple of oblong metallic patches with square corner cutting off and elliptic perturbation acting as electric dipole, and two couples of

In this letter, a rectangular-cavity-like structure is proposed to feed the phase gradient metasurface (PGM), where two symmetrical long slots are cut on side walls along wave propagation direction of the rectangular waveguide cavity resonator. It consists of rectangular waveguide, transition section, slotted-waveguide feed section, and shorted end of the cavity. The PGMs are placed in the slotted-waveguide

High energy, sub-nanosecond, single longitudinal mode (SLM) pulse is especially preferred for LiDAR application. In this paper, a kHz-level sub-nanosecond electro-optical Q-switched Nd:YVO4 laser of SLM operation for remote sensing was demonstrated. By utilizing a compact resonator with a Volume Bragg Grating as output coupler, maximum SLM output power of 1.08 W and pulse width of 919 ps was obtained

This work presents a compact broadband wide angular stable polarization-insensitive circuit analog absorber at sub 6 GHz. It shows almost 95% absorption from 2.26 to 5.76 GHz over the entire operating range. A transmission line equivalent circuit is modeled, and the response is validated. The design is obliquely stable up to 45° for both transverse electric and transverse magnetic incidences. The analysis

Photoacoustic spectroscopy (PAS) is a sensitive spectroscopic technique for trace gas sensing. As a key component of a PA sensor system, the cell constant of the cylindrical PA cell has been simulated for optimizing geometric design, and the acoustic pressure distribution and frequency response of the first longitudinal and radial modes are analyzed by using a self-established algorithm model. According

A cascade-based de-embedding technique is presented for microwave characterization of thin-film resistors and transmission lines. Parasitic effects of the probe pads, on-chip interconnects and access via holes can be directly extracted using two devices under test without resorting to any additional Open/Thru dummy structures. The proposed matrix transformation provides a simplified de-embedding methodology

Over the past two decades, pulsed-laser three-dimensional imaging flash lidar using avalanche photodiode (APD) arrays has attracted extensive research interest due to its great potential for both military and civilian applications. This invited paper gives a brief review of the state-of-art pulsed-laser three-dimensional imaging flash lidar using APD arrays. The principle of the pulsed-laser three-dimensional

In this letter, a polarization conversion metasurface antenna (PCMA) array for stealth design method is proposed. The array is composed of polarization conversion metasurface (PCM) subarray and their mirror subarray, which simultaneously plays the role of antenna element and PCM. So that, a certain phase cancellation can be produced between subarray and mirror one. The backward scattering is canceled

This paper presents an operator-friendly and cost-efficient approach to characterize the dielectric permittivity of liquids flowing in narrow tubes, such as drainage tubes used as part of the wound healing process in hospitals. The approach is based on an oscillator such that the characterization can be achieved with minimal operator (e.g., nurse) training. The oscillator's frequency is set by a 3D-printed

A dual-polarized three-dimensional absorptive frequency selective transmission (AFST) structure consisting of bent metallic strips embedded with chip-resistors, and a parallel plate waveguide has been introduced. The structure exhibits two wide absorption bands which flank both sides of the passband, and each absorption band contains two reflection zeros contributing to the wideband performance. An

This paper proposes a deep-learning-based wireless sensor system that uses an embedded two-dimensional (2D) light-emitting diode (LED) array to display measured sensor data and remote data transmission to detect nuclear power plant (NPP) equipment defects. The frequent use of electromagnetic waves often interferes with the operation of NPP. Therefore, we devised a wireless image transmission network

This article focuses on the design of super compact, polarization insensitive with wide angular stability, ultrathin triple-band metamaterial absorber. The unit cell comprising patches achieves almost perfect absorption (close to 100%) at C, X, and Ku band thereby justifying the term perfect metamaterial absorber. The structure provides 99.96%, 99.98%, and 99.62% absorptivity at the 4.75 GHz (C-band)

This article presents broadband, high gain, and highly efficient, leaky wave antenna for X-band applications. The proposed leaky wave antenna consists of periodic unit cells created by a combination of modified asymmetric meander line slots and an array of metallic via. The proposed unit cell configuration work as a composite left hand-right hand leaky wave transmission line and it is characterized

The contribution of this work is to propose a 3-dB parallel-line coupler design using the novel substrate integrated double-strip coaxial line (SIDSCL). The SIDSCL is composed of three substrates with two signal strips embedded in the center of the SIDSCL tunnel. The proposed coupler's coupled-line section formed by the SIDSCL's two broad-side-faced strips resolves the very difficult-to-achieved 3-dB

Electrical control of terahertz (THz) radiation for high-performance THz imaging is the key point. The spectrum suffers from a lack of active and available materials such as graphene have a severely limited bias range leading to restricted tuning. Therefore, here we demonstrated an efficient tunable device exploiting a triple bias layer for patterned graphene ribbons. Here, the patterned graphene acts

How to monitor the freshness of packaged food, the safety of sealed medicine, or the other substances in sealed space wirelessly and environment-friendly has become an urgent problem in recent years. After summarizing the theory of the LC sensor, a design of a paper-based resonator (30 mm × 30 mm × 0.15 mm) consisting of a finger capacitor is proposed in this paper. The sensor is embedded inside the

A plasmonic structure using gold nanorods (GNRs) on the surface of a tapered fiber was developed. The structure was used to study the Raman spectra of Rhodamine 6G (R6G) and zinc oxide (ZnO) adsorbed on the tapered optical fiber covered with the GNRs, respectively. The tapered optical fiber was manufactured by a dynamic etching process. The tapered fiber had a tip diameter in the nanometer range. The

A three-port planar multiple-input-multiple-output (MIMO) antenna system with pattern diversity based on the complementary theory is presented in this letter. Three directional antennas without any directors or reflectors are introduced as the radiating elements, which are rotationally symmetrical and sharing a small ground. The unilateral radiation pattern is achieved for each antenna element based

This letter introduces a compact elliptically-slotted patch antenna with Ku band reject characterizes. The proposed antenna works in the super wide range of frequency band stretched beyond the UWB. The slots in the radiating patch take the shape of ellipse and are present in such a manner that the double of their ellipticity follow the Fibonacci series. The perturbed-diamond-shaped patch without the

In this letter, in this process of using matrix pencil method (MPM) to perform the equivalent of the multiport frequency-dependent system, a modified MPM is proposed to realize the solutions of common poles and residue matrix in time domain. In this technique, the frequency domain data of all ports are transformed into the time domain matrix vectors by IFFT. Then, the time domain matrix vectors are

In this study, a novel tri-band bandpass filter supported by five resonant modes is developed on the basis of two coupled open-loop resonators with center-loaded bars (CLBs). Embedding the S-shaped resonator into the open-loop structure generates a new passband while keeping the same layout area. Also, another LB located between the open-loop resonator and the CLB is introduced to provide the perturbation

A compact pattern diversity patch antenna working at 5.8 GHz is proposed. The patch antenna has two ports, which are responsible for the broadside radiation and omni-directional radiation, respectively. The broadside radiation is achieved by inserting a substrate slot-loaded integrated waveguide (SIW) cavity at the center of the patch antenna, and the omni-directional pattern is realized by exciting

This article presents a dual-band bandpass (BP) to bandstop (BS) switchable filter with independently tunable center frequency and bandwidth. Two different length half-wavelength resonators are coupled with two separate coupling lines. Each resonator consists of a varactor-loaded stub at the center to tune the even mode frequencies, whereas two identical varactors are connected at the ends to tune

Worldwide, the most common malignancy in women is breast cancer. At present, the gold standard for breast cancer diagnosis, namely pathological analysis, cannot reach the subcellular level, and is unable to provide more physiological information. Multiphoton microscopy (MPM) has its unique advantages, such as label-free detection, high resolution, low damage, deep imaging depth, low photobleaching

In this paper, a new thin-film saturable absorber (SA) that belongs to the MXene family is used to generate Q-switched laser pulses. In constructing the SA, titanium carbide (Ti3C2Tx) powder obtained through a selective etching process is dispersed in polyvinyl alcohol solution before the mixture is dried to form a thin film. A small piece of the film is placed between two fiber ferrules to form a

Recently, a concept of linear wireless sensor networks (LWSNs) has attracted much attention. For such networks, one of the key challenges in sensor node design is to couple transceiver modules with bidirectional antennas placed back-to-back for opposite radiation. As is known, simply, this can be achieved by using well-known coupling options like radio frequency (RF) switch or splitter. However, it

A neural network (NN)-assisted probabilistic shaping (PS) distribution matcher is proposed, in which the model is simplified by a structured optimization method. The NN algorithm can encode the information sequence, making the signal obey the Gaussian distribution, and can directly restore the received signal. In addition, the algorithm uses the novel training method at both ends of the transmitter

Low-finesse fiber-optic Fabry–Perot (F-P) interferometric sensor has the advantages of high sensitivity, anti-electromagnetic interference, and compact size, and is one of the most widely used optical fiber sensors. With the development of sensor design and demodulation algorithms, F-P sensing technique plays an increasingly important role in high-speed dynamic measurement, such as dynamic temperature

In this article, we demonstrate a laser diode pumped passively Q-switched Yb3+:Sc2SiO5 (Yb:SSO) laser for the first time, applying a graphdiyne (GDY) saturable absorber which was prepared by the liquid phase exfoliation method. Utilizing the saturable absorption characteristic of the two-dimensional GDY material, the pulsed Yb:SSO laser performances were investigated. The single pulse energy of 9.0 μJ

A tunable third-order bandpass filter (BPF) with constant fractional bandwidth (CFBW) is presented. Only two quarter-wavelength resonators have been used in comb-line fashion to design the third-order BPF. The physical dimensions of the resonators have been decided to satisfy the filter specifications by synthesizing the coupling matrix. Using modal voltage waveform analysis, locations of the varactors

Different from previous phase gradient metasurfaces, in this letter we show that the spoof plasmon polariton conversion is dominated by the high-order surface wave modes rather than the pre-defined linear phase distribution. The latter becomes invalid due to the coupling between different metallic unit cells of the metasurface. To demonstrate this point, a metasurface, which includes six different

Experimental characterization of an amplifier's nonlinear properties at 24 GHz is presented in single and dual-band operation using orthogonal frequency-division multiplex signals. A test system for characterizing an amplifier's nonlinear properties at millimeter-wave frequencies for single and dual-band excitation is presented. The use of standard instrument enables a feasible test system. Analytical

A kind of chips on board (COB) package of light emitting diode (LED) light source is designed and produced. By reducing the current density and using the mirror aluminum substrate with high reflectivity to improve the luminous efficiency. Meanwhile, three kinds of red phosphors with peak wavelength of 630 nm, 631 nm and 639 nm are added on the basis of yellow-green phosphors, which increase within

A high voltage responsivity detector in G-band is designed in this paper. Different grounding models for the terahertz detector are analyzed and designed. Gold wire grounding design is superior to traditional grounding designs, which reduce the influence caused by the doping concentration, position and thickness error of conductive adhesive. Detectors are based on the Virginia Diodes Inc G-band zero-bias

This paper presents a bandwidth and center frequency tunable bandpass filter with wide tuning range. The proposed filter employs two cascade cross-shaped resonators. The cross-shaped resonator can generate two independent tunable transmission zeros by introducing two microwave varactors. The center frequency and bandwidth can be tuned by adjusting the DC bias voltages applied to the varactors. For