A novel miniaturized five band metamaterial inspired slot antenna is reported. The proposed design consists of a ring monopole and metamaterial Rectangular Complementary Split Ring Resonator (RCSRR) as the radiating part, two L and one T–shaped slot as the ground plane, respectively. Miniaturization in the proposed design is accomplished by metamaterial RCSRR, and also, it helps the antenna to operate at 2.9 and 5.2 GHz frequency bands. The aforementioned miniaturization process leads to about 46.8% reduction in volume of the proposed design, as compared to the conventional antenna. The pass band characteristics of the metamaterial RCSRR through waveguide medium are discussed in detail. In order to enhance the operating abilities of the miniaturized antenna, slots are etched out in the ground plane, thereby making the miniaturized antenna further operate at 2.4, 5.6 and 8.8 GHz, respectively. The proposed design has an active patch area of only , with dB bandwidth of about 4.16% (2.35–2.45 GHz), 5.71% (2.63–2.76 GHz), 10.25% (4.44–4.92 GHz), 6.25% (5.42–5.77 GHz) and 2.39% (8.68–8.89 GHz) in simulation, and about 6.86% (2.25–2.41 GHz), 5.01% (2.55–2.7 GHz), 9.16% (4.58–5.02 GHz), 5.38% (5.79–6.11 GHz) and 5.42% (8.44–8.91 GHz) in measurement. The antenna has good impedance matching, acceptable gain and stable radiation characteristics across the operational bandwidths.

A miniaturized metamaterial slot antenna for wireless applications

This communication presents a novel cactus-shaped ultrawideband (UWB) monopole antenna fabricated on liquid crystal polymer (LCP). The proposed antenna is a very compact design, since it can be fabricated on a board with dimensions only $20\times28$ mm $^{2}$ , while the three linear segments that comprise the cactus-shaped monopole provide a direct control on antenna matching. The proposed antenna is operating from 2.85 to 11.85 GHz and it presents very consistent omnidirectional patterns throughout the UWB frequency range. Return loss and pattern measurements are presented and the operation principles are discussed in detail. The simplicity of this topology, with the easily controllable return loss, allows for its easy implementation for various UWB subband designs, just by building suitable monopole versions, for which the only difference is the length of the three linear segments.

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Design and Development of a Compact UWB Monopole Antenna With Easily-Controllable Return Loss

A compact multiband antenna using λ/4 rectangular stub loaded with metamaterial for IEEE 802.11N and IEEE 802.16E

An ultralow-profile, electrically small, pattern-reconfigurable metamaterial-inspired Huygens dipole antenna is presented that operates near 1.5 GHz. The design incorporates two pairs of magnetic and electric near-field resonant parasitic (NFRP) elements and a reconfigurable driven element. A pair of p-i-n diodes is integrated into the driven element to enable the antenna pattern reconfigurability. By switching the ON/OFF states of the diodes, the antenna can realize two independent unidirectional endfire radiating states whose peaks point in antipodal directions and a bidirectional endfire radiating state. The measured results, in good agreement with their simulated values, demonstrate that although the antenna is electrically small ( ka = 0.98) and ultralow profile ( $0.0026\lambda _{0}$ ), it can realize uniform peak realized gains (RGs) of ~5.4 dBi, front-to-back ratios (FTBRs) of ~13.3 dB, and radiation efficiencies of (REs) ~85% in its two oppositely directed endfire states, and a RG of ~3.55 dBi and RE of ~87% in its bidirectional endfire state.

Ultralow-Profile, Electrically Small, Pattern-Reconfigurable Metamaterial-Inspired Huygens Dipole Antenna

A novel concept of using fractal antenna with metamaterial and slot to achieve multiband operation is investigated. The antenna consists of an L-shaped slot, Sierpinski triangle (used as fractal) as the radiating part and metamaterial circular split ring resonator (SRR)
as the ground plane. The introduction of metamaterial in the ground plane makes the antenna operate at 3.3 GHz (middle WiMAX). The etching of Sierpinski triangle and L-shaped slot in the radiating monopole perturbs the surface current distribution; thereby increasing the total
current path length which tends the antenna to further operate at 5.5 (upper WiMAX), 7.3 (satellite TV) and 9.9 GHz (X-band), respectively. The extraction of medium parameter of a circular SRR through waveguide medium is discussed in detail. The antenna has a compact dimension of 0.33λ0 × 0.27λ0 × 0.01λ0 = 30 mm× 24.8 mm× 1.6 mm, at a lower frequency of 3.3 GHz. Under simulation, antenna operates at 3.3, 5.5, 7.3 and 9.9 GHz with S11 < −10 dB
bandwidth of about 5.9% (3.24–3.44 GHz), 5.6% (5.31–5.62 GHz), 7.3% (6.99–7.52 GHz) and 3.02% (9.78–10.08 GHz), respectively. In measurement, antenna exhibit resonances at 3.1, 5.52, 7.31, 9.72 GHz with S11 < −10 dB bandwidth of about 3.5% (3.04–3.15 GHz), 5.01% (5.44–5.72 GHz), 13.2% (6.76–7.72 GHz) and 5.77% (9.42–9.98 GHz), respectively. Good impedance matching and stable radiation characteristics are observed across the operational
bandwidth of the proposed configuration

A fractal quad-band antenna loaded with L-shaped slot and metamaterial for wireless applications

A compact coplanar waveguide (CPW)-fed triple-band monopole antenna with high-band isolation for various wireless applications is presented. The proposed antenna is composed of a CPW-fed structure and a hexagon-shaped patch on which a hexagon-shaped slot is etched for covering the wireless local area network (WLAN) band (2.4/5.2/5.8 GHz), and occupies a very compact size of 26 × 25 mm2. By introducing a half-hexagon-shaped stub, additional bands can be realised covering the worldwide interoperability for microwave access (WIMAX) band (2.5/3.5/5.5 GHz). The proposed antenna has been fabricated and measured; results show a higher isolation between adjacent bands, good radiation pattern characteristics and stable gains in the operating bands. The simple feeding structure, compact size and uniplanar design make it easy to be integrated within portable devices for wireless communication.

Compact CPW-fed triple-band antenna for diversity applications

A broadband gain enhancement endfire antenna is presented. The gain enhancement is achieved by loading with an I-shaped resonator (ISR) structure in the endfire direction. Broad bandwidth is realised by using a microstrip-to-coplanar balun and bowtie dipole elements, while gain enhancement is achieved by loading the ISR structure in the endfire direction. The measurements show that the ISR-loaded antenna presents a gain of about 4-8 dB in the whole working band (4.5-9.5 GHz), which is about 2 dB more than the unloaded one. The advantages of broad bandwidth and high gain make this antenna valuable in wireless communication systems.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/el.2013.1198

Gain enhancement for wide bandwidth endfire antenna with I‐shaped resonator (ISR) structures

A compact coplanar waveguide-feed monopole antenna with dual-band characteristics is proposed in this article. The proposed antenna mainly consists of meander T-shaped monopole and small ground plane embedded with a pair of L-shaped couple slots and two pairs of I-shaped notched slots symmetrically. By elongating the meander T-shaped arms and carefully selecting the positions and lengths of L-shaped slot and I-shaped slot, the antenna excites four resonant frequencies at 2.42, 2.52, 4.75, and 5.54 GHz which are formed into two wide bands to cover all the 2.4/5.2/5.8 GHz wireless local area network (WLAN) operating bands, and is with miniaturization structure. Moreover, the antenna can provide nearly dipole-like radiation patterns and good gains across the dual operating bands. These results prove that the proposed dual-band antenna is very suitable for WLAN applications. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. © 2013 Wiley Periodicals, Inc.

Compact meander T-shaped monopole antenna for dual-band WLAN applications

A novel and compact decoupling and matching network (DMN) is proposed for two symmetric antennas. The DMN is designed and analysis by the lumped-element circuit and the even/odd mode analysis proved the feasibility of the network for a two-element closely spaced array. Then the network is fulfilled by a microstrip line. The measurement results (both with the advanced design system and the high frequency structure simulator) agree quiet well with the simulation ones. High antenna isolation and good matching are achieved simultaneously. The design concept, formulation and experimental results are introduced.

Compact microstrip decoupling and matching network for two symmetric antennas

This paper presents a novel stacked patch antenna design with stable radiation and high gain characteristics. The presented antenna provides the bandwidth from 2.4 GHz to 2.483GHz. This bandwidth is realized by stacking the copper sheet. The bandwidth of the stacked antenna is narrow, but results in stable radiation patterns and high gain in the operating band, and the main gain can achieve 8.9dBi.

Peng Wang

Papers

Compact CPW-fed triple-band antenna for diversity applications

Gain enhancement for wide bandwidth endfire antenna with I‐shaped resonator (ISR) structures

Compact meander T-shaped monopole antenna for dual-band WLAN applications

Compact microstrip decoupling and matching network for two symmetric antennas

A novel stacked-patch endfire antenna