Nowadays synthetic aperture radar (SAR) and multiple-input-multiple-output (MIMO) antenna systems with the capability to radiate waves in more than one pattern polarization are playing a key role modern telecommunication systems. This is possible use of arrays as they offer advantages high gain beamforming capability, which can be utilized for controlling radiation electromagnetic (EM) interference immunity wireless However, growing demand compact array antennas, physical footprint needs...

In this review paper, a comprehensive study on the concept, theory, and applications of composite right/left-handed transmission lines (CRLH-TLs) by considering their use in antenna system designs have been provided. It is shown that CRLH-TLs with negative permittivity (ε <; 0) permeability (μ unique properties do not occur naturally. Therefore, they are referred to as artificial structures called "metamaterials". These include series left-handed (LH) capacitances (C <sub...

An approach is proposed to reduce mutual coupling between two closely spaced radiating elements. This achieved by inserting a fractal isolator the The an electromagnetic bandgap structure based on metamaterial. With this technique, gap radiators reduced ~0.65λ for reduction in of up 37, 21, 20, and 31 dB X-, Ku-, K-, Ka-bands, respectively. two-element antenna shown operate over wide frequency range, i.e., 8.7-11.7, 11.9-14.6, 15.6-17.1, 22-26, 29-34.2 GHz. Maximum gain improvement 71% with...

Antennas on-chip are a particular type of radiating elements valued for their small footprint. They most commonly integrated in circuit boards to electromagnetically interface free space, which is necessary wireless communications. radiate and receive electromagnetic (EM) energy as any conventional antennas, but what distinguishes them miniaturized size. This means they can be inside electronic devices. Although antennas have limited range, suitable cell phones, tablet computers, headsets,...

This paper focuses on the determination and analysis of an accurate small-signal equivalent circuit for gallium-nitride high electron-mobility transistors under different bias conditions. Our experimental results show that a channel capacitance has to be added conventional forward "cold" model modeling device-under-test. The validity proposed extraction procedure been verified by very good agreement between simulated measured scattering parameters up 50 GHz

A decoupling metamaterial (MTM) configuration based on fractal electromagnetic‐bandgap (EMBG) structure is shown to significantly enhance isolation between transmitting and receiving antenna elements in a closely‐packed patch array. The MTM‐EMBG cross‐shaped assembly with fractal‐shaped slots etched each arm of the cross. fractals are composed four interconnected‐‘Y‐shaped’ that separated an inverted‐‘T‐shaped’ slot. placed individual antennas 2 × Measured results show average inter‐element...

This paper presents a unique technique to enhance isolation between transmit/receive radiating elements in densely packed array antenna by embedding metamaterial (MTM) electromagnetic bandgap (EMBG) structure the space suppress surface currents that would otherwise contribute towards mutual coupling elements. The proposed MTM-EMBG is cross-shaped microstrip transmission line on which are imprinted two outward facing E-shaped slits. Unlike other MTM structures, there no short-circuit...

In this paper, an overview of recently reported low-noise amplifiers (LNAs), designed, and fabricated in GaN technology is provided, highlighting their noise performance together with high-linearity high-robustness capabilities. Several SELEX-ES monolithic technologies are detailed, providing the results characterization modeling on sample devices. An in-depth review three LNAs based 0.25- μm HEMT process, marginally described previous publications, then presented. particular, two robust...

This paper presents a study of planar antenna-array inspired by the metamaterial concept where resonant elements have sub-wavelength dimensions for application in microwave medical imaging systems detecting tumors biological tissues. The proposed antenna consists square-shaped concentric-rings which are connected to central patch through common feedline. array structure comprises several antennas that arranged surround sample breast model. One at time is used transmission-mode while others...

Abstract This paper presents the results of a study on improving performance parameters such as impedance bandwidth, radiation gain and efficiency, well suppressing substrate loss an innovative antenna for on-chip implementation millimetre-wave terahertz integrated-circuits. was achieved by using metamaterial substrate-integrated waveguide (SIW) technologies. The structure comprises five alternating layers metallization silicon. An array circular patches with metamaterial-inspired...

This letter investigates the feasibility of designing a high gain on-chip antenna on silicon technology for subterahertz applications over wide-frequency range. High is achieved by exciting using an aperture fed mechanism to couple electromagnetics energy from metal slot line, which sandwiched between and polycarbonate substrates, 15-element array comprising circular rectangular radiation patches fabricated top surface layer. An open ended microstrip orthogonal slot-line, implemented...

A metamaterial photonic bandgap (MTM‐PBG) periodic structure is used as a decoupling frame to improve the isolation between transmit–receive (T/R) sections of densely packed array antenna in synthetic aperture radar (SAR) and multiple‐input–multiple‐output (MIMO) systems. With this technique MTM‐PBG shown effectively suppress surface wave propagations T/R antennas by an average 12 dB. layer comprises arrangement dielectric circles etched cross‐shaped microstrip that inserted radiating...

Abstract This paper presents the results of a study on developing an effective technique to increase performance characteristics antenna arrays for sub-THz integrated circuit applications. is essential compensate limited power available from sources. Although conventional array structures can provide solution enhance radiation-gain however in case small-sized radiation properties be adversely affected by mutual coupling that exists between radiating elements. It demonstrated here...

Abstract An effective method is presented for suppressing mutual coupling between adjacent radiating elements which based on metasurface isolation multiple‐input multiple‐output (MIMO) and synthetic aperture radar (SAR) systems. This achieved by choking surface current waves induced over the patch antenna inserting a cross‐shaped structure elements. Each arm of constituting etched with meander line slot. Effectiveness demonstrated 2 × array that operates six frequency subbands in X, Ku, K...

Abstract The paper presents a technique to enhance the isolation between adjacent radiating elements that is common in densely packed antenna arrays. Such antennas provide frequency beam‐scanning capability needed multiple‐input multiple‐output (MIMO) systems and synthetic aperture radars. method proposed here uses metamaterial decoupling slab (MTM‐DS), which located elements, suppress mutual coupling would otherwise degrade efficiency performance both transmit receive mode. MTM‐DS consists...

Surface transfer doping of hydrogen-terminated diamond has been achieved utilising V2O5 as a surface electron accepting material. Contact between the oxide and promotes electrons from into revealed by synchrotron-based high resolution photoemission spectroscopy. Electrical characterization Hall measurement performed before after deposition shows an increase in hole carrier concentration 3.0 × 1012 to 1.8 1013 cm−2 at room temperature. High temperature measurements up 300 °C atmosphere reveal...

In this communication, a novel dual-polarized highly folded self-grounded Bowtie antenna that is excited through I-shaped slots proposed for applications in sub-6 GHz 5G multiple-input-multiple-output (MIMO) systems. The consists of two pairs radiation petals whose base embedded double layer FR-4 substrate with common ground-plane which sandwiched between the layers. defected located under elements. Each pair elements are microstrip line on top RF signal 180&#x00B0; out phase respect to each...

A design of mobile-phone antenna array with diamond-ring slot elements is proposed for fifth generation (5G) massive multiple-input/multiple-output (MIMO) systems. The configuration the consists four double-fed placed at different corners printed circuit board (PCB). low-cost FR-4 dielectric an overall dimension 75 × 150 mm2 used as substrate. are fed by 50-Ohm L-shaped microstrip-lines. Due to orthogonal placement microstrip feed lines, can exhibit polarization and radiation pattern...

Circular polarized (CP) antennas are well suited for long-distance transmission attainment. In order to be adaptable beyond 5G communication, a detailed and systematic investigation of their important conventional features is required expected enhancements. The existing designs employing millimeter wave, microwave, ultra-wideband (UWB) frequencies form the elementary platform future studies. 3.4–3.8 GHz frequency band has been identified as worthy candidate communications because spectrum...

The paper presents a feasibility study on the design of new metamaterial leaky-wave antenna (MTM-LWA) used in construction 1 × 2 array which is implemented using substrate-integrated waveguide (SIW) technology for millimetre-wave beamforming applications. proposed consists two LWAs with unit-cells etched top surface SIW. unit-cell, an E-shaped transverse slot, causes leakage loss and interrupts current flow over SIW to enhance array’s performance. dimensions LWA are 40 10 0.75 mm3....

Abstract This paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented two-layers polyimide substrates with thickness of 500 μ m. The aluminium ground-plane 3 m is sandwiched between the two-layers. Concentric dielectric-rings are etched in under radiation patches top-layer. comprise concentric metal-rings that arranged × matrix. antennas excited by coupling electromagnetic energy through gaps microstrip feedline created bottom polyimide-layer....

This paper presents a multiple-input multiple-output (MIMO) antenna system for millimeter-wave 5G wireless communication services. The proposed MIMO configuration is composed of four elements, where each possesses an HP-shaped that features simple and excellent performance. design can operate at very wideband 36.83–40.0 GHz (measured). Furthermore, the attains peak gain 6.5 dB with maximum element-isolation −45 dB. Apart from this, performance metrics such as envelope correlation coefficient...

In this article, an inverted L-shaped monopole eight elements Multiple Input Output (MIMO) antenna system is presented. The multi-antenna designed on a low cost 0.8 mm thick FR4 substrate having dimensions of 136×68 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> resonating at 3.5GHz with 6dB measured bandwidth 450MHz, and inter element isolation greater than 15 dB gain 4 dBi. proposed design consists parasitic strips extending from the...

Multiple-input multiple-output (MIMO) scheme refers to the technology where more than one antenna is used for transmitting and receiving information packets. It enhances channel capacity without power. The available space in modern compact devices limited MIMO elements need be placed closely. closely spaced antennas undergo an undesirable coupling, which deteriorates parameters. In this paper, ultra wide-band (UWB) system with improved isolation presented. has a wide bandwidth range from...