Tunable dual-band metamaterial using open stub-loaded stepped-impedance resonator

In this paper, we report a tunable planar metamaterial that is designed to achieve dual-band negative refractive index response in microwave regime. Its distinctive characteristic is the usage of tuning open stub-loaded stepped-impedance resonators. The frequency tunability of the second band is achievable via the adjustable open stub-loaded at the fixed tune of the first band. Parameter retrieval algorithm and full-wave simulation of prism-shaped structure were carried out to validate the negative refraction characteristics of metamaterial structure. The results predict its prospect as a very promising alternative to the conventional ones, which is compatibly applicable on various potential microwave devices especially when a dual-band function is required. In addition to that, its design flexibility offers various frequency bands at any possible choice, which alterable with the design parameters

Miniaturization Trends in Substrate Integrated Waveguide (SIW) Filters: A Review

This review provides an overview of the technological advancements and miniaturization trends in Substrate Integrated Waveguide (SIW) filters. SIW is an emerging planar waveguide structure for the transmission of electromagnetic (EM) waves. SIW structure consists of two parallel copper plates which are connected by a series of vias or continuous perfect electric conductor (PEC) channels. SIW is a suitable choice for designing and developing the microwave and millimetre-wave (mm-Wave) radio frequency (RF) components: because it has compact dimensions, low insertion loss, high-quality factor (QF), and can easily integrate with planar RF components. SIW technology enjoys the advantages of the classical bulky waveguides in a planar structure; thus is a promising choice for microwave and mm-Wave RF components

UWB Technology

Ultra Wide Band (UWB) technology has attracted increasing interest and there is a growing demand for UWB for several applications and scenarios. The unlicensed use of the UWB spectrum has been regulated by the Federal Communications Commission (FCC) since the early 2000s. The main concern in designing UWB circuits is to consider the assigned bandwidth and the low power permitted for transmission. This makes UWB circuit design a challenging mission in today's community. Various circuit designs and system implementations are published in this book to give the reader a glimpse of the state-of-the-art examples in this field. The book starts at the circuit level design of major UWB elements such as filters, antennas, and amplifiers; and ends with the complete system implementation using such modules

Recent Trends on Dual- and Triple-Band Microwave Filters for Wireless Communications

In the past few years, several designs of dual- and triple-band microwave filters satisfying various objectives have been proposed for wireless communication. Several designs are new concepts, whereas others are inspired from previous works. The development trends of these designs can be reviewed from this compilation of studies. This paper begins with an explanation of dual- and triple-band microwave filters, followed by a discussion on several designs in terms of size, measurement, performance, and technology use. Among various designs, microstrip band-pass filters are extensively used because of their simple design procedures and because they can be integrated into circuits easily. Furthermore, most researchers use low frequencies in their designs because of the demands of current wireless applications. Finally, designs are proposed to produce compact microwave filters with good performance

Development of novel tunable dual-band negative index metamaterial using open stub-loaded stepped-impedance resonator

This study reports on tunable planar metamaterial design that is capable to achieve dual-band negative index of refraction responses operating in microwave regime. Its distinctive characteristic is the usage of tuning open stub-loaded stepped-impedance resonators. Parameters retrieval algorithm, and full-wave simulation of prism-shaped structure were carried out to validate the negative refraction characteristics of metamaterial structure. The results predict its prospect as a very promising alternative to the conventional ones, which is compatibly applicable on various potential microwave devices especially when dual-band function is required. In addition to that, its design flexibility offers a various frequency bands at any possible choice, which is alterable together with any design parameters changes

Analysis of Open Stub Resonator and its Application in Dual Isolation Band of SPDT Switch Design

In this paper, an analysis of open stub resonator is presented and its application in dual isolation band of Single Pole Double Throw (SPDT) switch is proposed. A mathematical model and the characteristic of the bandstop of the resonator were analyzed and discussed. The open stub resonator was implemented using the microstrip transmission line and able to switch between bandstop and allpass responses. Frequency bands of 2.3 and 3.5 GHz were chosen to demonstrate the dual isolation band in the switch design. The performance results of the SPDT switch showed that the isolation was greater than 30 dB, return loss was greater than 10 dB and insertion loss less than 2 dB at the center resonant frequency of 2.3 and 3.5 GHz. The potential application of the proposed dual isolation band of SPDT switch is for multi band RF front-end system such as WiMAX, LTE, WiFi and HyperLAN

Microstrip multi-stopband filter based on tree fractal slotted resonator

This paper presents the design and development of a new microstrip multi-stopband filter based on tree fractal slotted resonator. A single square patch with tree fractal slots of different iterations are employed for realizing dual stopband and tri-stopband filters. The tree fractal slotted resonators are generated from conventional square patch using an iterative tree fractal generator method. First, second and third level iterations of the tree fractal slot resonator are used to design dual and tri-stopband filters respectively. The first level iteration introduced for the tree fractal slot realizes dual bands at 2.64 GHz and 3.61 GHz while the second level iteration provides better stopband rejection and insertion loss at 2.57 GHz and 3.56 GHz. The tri-stopband filter generates three resonance frequencies at 1.53 GHz, 2.53 GHz and 3.54 GHz at third level iteration. By varying the slot length and width of the tree fractal slot, the resonant frequencies can be adjusted and stopbands of the proposed filter can be tuned for the desired unwanted frequency to be rejected. The proposed narrowband filters finds application in removing the interference of GPS and Wi-Max narrowband signals from the allotted bands of other wireless communication system

Band-pass filter based on complementary split ring resonator

This letter presents a new circuit of the band-pass filter designed by using microstrip technology. Based on complementary split ring resonator and various series of optimization technic and a specific design method, a miniature band-pass filter with excellent electrical performances is achieved. First of all, the metamaterial unit cell is studied to obtain a desired resonant frequency and it is implemented in the ground plan in order to increase the characteristics of the bandpass behavior and decrease its operating frequencies. This proposed circuit is designed on an FR-4 substrate having a relative permittivity of 4.4 tangential losses of 0.025 and thickness of 1.6 mm. This filter is developed by using CST Microwave. The obtained features allow this filter to be used in diverse wireless applications such as IMT-E and WiMax

A Compact Triple Band Metamaterial Inspired Bandpass Filter Using Inverted S-shape Resonator

This paper represents the compact metamaterial inspired triple-band filter using two inverted S-shape resonator and two C-shape stub with via. Proposed filter is printed on FR-4 epoxy glass substrate with 1.6 mm thickness. The measured 3 dB fractional bandwidth of 40 % (1.6-2.4 GHz), 16.5 % (3.9-4.6 GHz) and 14.3 % (5.2-6.0 GHz) at centre frequencies 2.0 GHz, 4.25 GHz and 5.6 GHz respectively. This filter offers electrical circuit size of 0.22λg × 0.16λg, where given λg is the guided wavelength at centre frequency of first passband 2.0 GHz. The performance parameter of designed filter have characterized by fractional bandwidth, insertion loss, dielectric constant, return loss, circuit size and group delay. Both simulated and measured results are shown to validate the proposed filter. Finally, the MTM properties of proposed filter has been verified by extracting its dispersion diagram. It is suitable for GSM 1800, LTE 2300 and WiMAX (5.2-5.8 GHz) application

A Review on Different Techniques of Mutual Coupling Reduction Between Elements of Any MIMO Antenna. Part 2: Metamaterials and Many More

This two‐part article presents a review of different techniques of mutual coupling (MC) reduction. MC reduction is a primary concern while designing a compact multiple‐input‐multiple‐output (MIMO) antenna where the separation between the antennas is less than λ0/2, that is, half of the free‐space wavelength. The negative permittivity and permeability of artificially created materials/structures (Metamaterials) significantly help reduce MC among narrow‐band compact MIMO antenna design elements. In this part two of the review paper, we will discuss techniques: Metamaterials; Split‐Ring‐Resonator; Complementary‐Split‐Ring‐Resonator; Frequency Selective Surface, Metasurface, Electromagnetic Band Gap structure, Decoupling and Matching network, Neutralization line, Cloaking Structures, Shorting vias and pins and few more