In this study, the implicit Crank?Nicolson finite-difference time-domain (CN-FDTD) method is applied to discretize the governing telegrapher's equations of a composite right-/left-handed (CRLH) coupled-line coupler. The unconditionally stable CN-FDTD is compared with the conventional leap-frog (LF) FDTD method. The results obtained from the CN-FDTD scheme show up to 10 times increase in the tempor

Design and development of 2 kW, 3 dB tandem hybrid coupler for the frequency range of 155?225 MHz has been presented in this paper. The developed 3 dB coupler is to be used in a prototype of Ion Cyclotron Resonance Frequency (ICRF) system of Tokamak, which has been developed to test the resilience of ICRF network during continuously variable RF load excursions. The 3 dB coupler divides the RF powe

In through the wall imaging systems, wall parameters like its thickness and dielectric constant play an important role in the true and correct image formation of an object behind the wall made of various materials like brick cement, wood, plastic, etc. Incorrect estimation of these parameters leads to dislocation of the object and smearing or blurriness of the image too. A new autofocusing techniq

A planar inverted F-Antenna with the dual band-dual polarization property is presented for medical body area networks applications. The designed antenna covers the 2.45 GHz industrial, scientific and medical, 4 G long term evolution (2.5?2.69 GHz) bands for ON body communication and Wi-Fi and WLAN (3.5?3.6 GHz) bands for OFF body communication. At the lower band, an equivalent offset fed magnetic

A novel low profile dual band patch antenna is presented. It consists of a composite right/left-handed transmission line (CRLH TL) unit cell gap coupled with the radiating edge of a rectangular patch antenna. The dual band behavior is achieved by coupling the zeroth order resonance mode of CRLH TL and TM mode of the patch antenna. It is shown that frequency ratio can be changed by varying the gap

A simple design for triple-band circularly polarized (CP) wide slot antennas is proposed and experimentally investigated. The proposed antenna having a microstrip-fed rectangular patch with -shaped notch for triple-band operation and a modified wide square slot on ground plane for CP operation. The measured 10 dB reflection bandwidths are 1.24% (?340 MHz from 2.56 to 2.9 GHz), 9.63% (?430 MHz from

In this paper, a novel low-profile planar monopole internal antenna for GSM/DCS/PCS/ IMT/UMTS/WLAN/ISM/LTE operation in the mobile phones is designed and developed. The proposed antenna is composed of multi-branches, F-shaped slots in the system ground plane and tapered feeding line which can improve the impedance matching at the feeding point. The antenna occupying a small area of 18.5 × 46 mm is

The paper researches a kind of wideband dual-polarized Vivaldi antenna with improved balun feed which consists of slot line and two bent coplanar strip lines. The whole of antenna structure is composed of two orthogonal Vivaldi antenna elements, and the mode of feeding adopts electromagnetic coupling from micro-strip line to slot line. The improved balun can avoid the intersection of transmission

This paper presents a cavity-backed dual-slot antenna in 0.13-?m SiGe BiCMOS technology. The dual-slot structure is excited by a cross-shaped strip line and a cavity which is formed by the topmost metal layer connected to the bottom metal layer through vias in between. By adopting dual-slot and cross-shaped feed line, the bandwidth is significantly enhanced by 196% compared with the single-slot an

A compact circularly polarized antenna with wide axial ratio bandwidth (ARBW) using quasi-self-complementary (QSC) structure is presented. A 3-dB ARBW is achieved by shortening the ground plane of the QSC structure. Furthermore, the wide ARBW is obtained by the introduction of a stepped stub in the extended ground plane of the QSC structure. The antenna is fabricated on a FR4 substrate with the ov

To improve detection performance of passive location system based on troposcatter, we propose a blind signal detection algorithm. According to our algorithm, complementary ensemble empirical mode decomposition decomposes the received signal into several intrinsic mode functions (IMFs). To reconstruct the signal and background noises, difference between the entropy of adjacent IMFs is utilized as a

In this paper, a high-gain dual-band distributed amplifier (DBDA) based on the metamaterial transmission line (TL) is proposed. To have two separate frequency bands in the distributed amplifiers, the composite right/left-handed (CRLH) TLs are used instead of conventional TLs. Although both forward and reverse gains of the distributed amplifiers are available in this case, they suffer from their lo

A compact dual-wideband (DWB) bandpass filter utilizing open-shorted coupled lines (OSCL) is proposed in this paper. The introduction of the folded structure not only reduces the overall size but also contribute to the split of the transmission zero (TZ), which improves the selectivity effectively. Six transmission poles and five TZs are realized utilizing the shorted-circuit stub and OSCL. The ch

The ultra-wideband bandpass-response power divider with high-frequency selectivity is presented in this paper. This power divider consists of an impedance transformer, a filter network, and two isolation resistors. In order to realize the ultra-wideband filtering performance, parallel coupling lines and parallel open-circuit branches are applied to the second impedance converter. A resistor is add

This paper presents a miniaturized 3-dB branch-line coupler based on slow-wave microstrip transmission lines. The miniaturized coupler operating at 2.45 GHz is designed and implemented on a double-layer printed circuit board substrate with blind metallic vias embedded in the lower substrate layer providing the slow-wave effect. Based on this concept, a 43% size miniaturization is achieved as compa

Pulse compression technique allows a radar to achieve the resolution of a short pulse and the energy of a long pulse simultaneously, without the requirement of high-power transmission. Therefore, pulse compression radars have a low probability of intercept capability. The common types of pulse compression signals are frequency modulated waveforms and phase-coded waveforms, which have different pro

This paper aims at investigating the dependence of the impedance and the radiation characteristics of a cylindrical dielectric resonator antenna (DRA), on the feed point of the DRA. It is demonstrated that the resonant frequency, bandwidth, radiation pattern symmetry, and cross-polarized radiation levels depend highly on the feed point. Three standard single-ended feed mechanisms such as the micro

Frequency- and time-domain characteristics as well as indoor propagation channel impulse response of a compact dual band-notched ultra-wideband (UWB) slot antenna are investigated in this paper. The antenna consists of a narrow rectangular radiation patch and a rectangular wide slot in the modified ground plane. A pair of -shaped stubs are connected to the radiation patch to obtain band-notched pr

In this paper, we present a novel dual-band wearable compact flexible antenna for body-centric wireless communications (BCWCs). The design is based on a modified planar dipole with parasitic elements, meandered lines, and a rectangular reflector embedded into a hydrophobic rubber-textile multilayer substrate in order to get both good antenna performance and mechanical properties. The antenna's str

A coplanar waveguide slot antenna is herein presented. A rectangular slot is excited by a Y-shaped monopole etched on a single FR4 substrate. This structure exhibits two resonances due to the presence of the slot and the central monopole which can be used to design a dual-band or a wideband antenna. A parametric analysis is presented to describe the impedance matching mechanism for the two impedan

A modified H-shaped metamaterial is imparted in this paper that has a multiple band coverage for reflection and transmission coefficient. The proposed structure exhibits triple band coverage for the permittivity and permeability. Two split ring resonators (SRR) are connected with the substantial H-shaped structure. The 12 × 12 mm structure has been printed on FR-4 and a correlation is made between

A new planar multiple-input?multiple-output (MIMO) antenna for ultra wideband (UWB) applications is presented. The proposed antenna operates over the frequency band from 3.1 to 10.6 GHz and it consists of two identical circular monopoles on an FR substrate. The wide isolation is achieved through a novel planar decoupling structure that is being inserted between the dual antennas. Moreover, a cente