Monopole-like Radiation Pattern Research Articles

All‐textile higher order mode circular patch antenna for on‐body to on‐body communications

An all-textile higher order mode circular patch antenna for on-body to on-body communications is proposed. The proposed antenna is compact in size and consists of a coaxially centre-fed circular patch with two shorting vias to generate the TM 21 higher order resonance mode for a monopole-like radiation characteristic. The antenna is fabricated by using a conductive textile, conductive thread and a felt substrate. The bandwidth can fully cover the 2.45 GHz ISM band while achieving a low-profile configuration. The effects of antenna deformation because of bending and the human body are analysed when the antenna is placed on a two-thirds muscle-equivalent phantom and a full-scale human model. The performance of the antenna is minimally affected by antenna deformation and the human body because of the TM 21 higher order mode excitation and its monopole-like radiation pattern.

Dual-band metamaterial-inspired antenna for mobile applications

In this letter, a metamaterial (MTM) inspired antenna is designed to operate at DCS, GSM1800, WCDMA, and Bluetooth and hence shows good potential to be used in mobile applications. The proposed antenna shows n characteristics with first band (1.61–1.84 GHz) resonant at 1.72 GHz and second (2.08–2.5 GHz) at 2.17 GHz with substrate dimensions of 0.29λo × 0.29λo × 0.01λo. Percentage input impedance bandwidth (S11 < −6 dB) is 13.4% for first and 19.4% for second band, respectively. The proposed antenna shows monopole-like radiation pattern in xz-plane while dipolar-type in yz-plane at both frequencies of operation, respectively. The measured gain of proposed antenna is 1.8 and 1.6 dB at 1.72 and 2.17 GHz with radiation efficiency of 97.2 and 99.1%, respectively. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1444–1447, 2015

A novel FGCPW-fed flag-shaped UWB monopole antenna

A finite-ground coplanar waveguide (FGCPW)-fed compact ultra-wideband flag-shaped monopole antenna is presented. The antenna consists of a FGCPW-fed monopole asymmetrically loaded with a rectangle strip. The antenna has a compact size of 21.85 × 28 × 1.6 mm3. Parametric analysis is conducted to understand the effect of various parameters on the antenna performance. Simple design equations are presented to provide reliable initial design of the antenna if a different substrate is to be used. Constant gain and monopole-like radiation patterns are observed along the entire operating range from 3.1 to 12 GHz. Investigation of the time domain characteristics reveals that the proposed antenna exhibits excellent pulse handling capabilities.

Compact Low-Profile Dual-Band Patch Antenna Using Novel TL-MTM Structures

A low-profile, single-feed, single-layered dual-band patch antenna using mushroom-like transmission-line metamaterial (TL-MTM) structures is proposed in this letter. The characteristics of the new proposed TL-MTM structure are initially studied in detail by circuit analysis and HFSS simulation, and the working mechanism and radiation performances of the antenna are examined and illustrated for the two operating bands, respectively. The proposed antenna occupies an overall size of 0.22λg×0.22 λg×0.042λg. Measured results exhibit that the fabricated antenna has a monopole-like radiation pattern with an efficiency of 79.4% at 2.76 GHz, and a patch-like radiation pattern with an efficiency of 90.8% at 5.23 GHz.

Stepped Cylindrical Antenna with a Higher-Order Mode Ring Patch for Wideband Conical Radiation Pattern

A stepped cylindrical antenna with a higher-order mode ring patch for wideband conical radiation pattern is proposed. To accomplish a low profile with wideband conical radiation characteristics, a stepped cylindrical monopole and a TM41higher-order mode ring patch with four shorting pins are utilized. The proposed antenna has a monopole-like radiation pattern with a wide 10-dB return loss bandwidth of 11 GHz (2 GHz–13 GHz). It can cover various wireless services, such as wireless broadband (WiBro; 2.3 GHz–2.39 GHz), wireless local area networks (WLAN; 2.4 GHz–2.484 GHz, 5.15 GHz–5.35 GHz, and 5.725 GHz–5.875 GHz), digital multimedia broadcasting (DMB; 2.63 GHz–2.655 GHz), and ultra wideband (UWB; 3.1 GHz–10.6 GHz). The antenna has a height of only 0.12λ0at 2 GHz.

Multiband Metamaterial-Loaded Monopole Antenna for WLAN/WiMAX Applications

A simple multiband metamaterial-loaded monopole antenna suitable for wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications is proposed in this letter. The rectangle monopole of the proposed antenna is originally designed to resonate at around 5.2 GHz. When the inverted-L slot is etched, the antenna produces a second resonance at around 4.1 GHz. Then, with the addition of the metamaterial reactive loading, the resonant frequency of the antenna will be shifted down, and a third resonance covering the 2.4-GHz band occurs. Consequently, the antenna can cover the 2.4/5.2/5.8-GHz WLAN and 2.5/3.5/5.5-GHz WiMAX bands with a very compact size of only 12.9 ×6.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Monopole-like radiation patterns and acceptable gains and efficiencies have been obtained. Details of the antenna design as well as the experimental results are presented and discussed.

DESIGN OF A WIDEBAND SLEEVE ANTENNA WITH SYMMETRICAL RIDGES

In this letter, a novel sleeve antenna with wideband characteristic is presented for wireless communication applications. By employing a sleeve structure, impedance bandwidth of the antenna is improved through exciting a new resonant point. To obtain an impedance bandwidth enhancement further, four symmetrical ridges are introduced between the sleeve and the main radiator. An excellent wideband impedance bandwidth for VSWR ≤ 2 of 148.45% is achieved, covering the frequency range from 1.04 to 7.03 GHz, and good monopole-like radiation patterns are obtained where the un-roundness in the H-plane is less than 1.49 dB. It is very suitable for recent wireless communication services such as DCS, PCS1900, UMTS, IMT2000, WLAN, WiMAX2350/3500, WiBro, etc.

AN ULTRA-WIDEBAND TWIN-PATCH MONOPOLE ANTENNA WITH BAND-REJECTION CHARACTERISTIC

To suppress electromagnetic interference at 5.5-GHz WLAN (5.15-5.825 GHz) band operation, a novel ultra-wideband (UWB) design of a slotted twin-patch monopole antenna with a band-rejection characteristic is presented. The proposed antenna with a simple structure has a large impedance bandwidth, defined by 10-dB return loss, covering the range from 2.95 to 10.85 GHz, and a tunable cutoff band from 5.18 to 6 GHz for band-operation suppression. Measured monopole-like radiation pattern and in-band average gain of about 2.3 dBi have also been obtained, simultaneously, with good agreement to the simulated results.

Dual‐band dual‐mode patch antenna for on–on–off WBAN applications

A dual-band dual-mode patch antenna for on–on–off wireless body area network (WBAN) applications is proposed. The antenna consists of a half-circular patch with two shorting posts to generate a TM41 higher-order resonant mode and a bottom ground slot to generate additional resonance. To reduce the antenna size without seriously affecting the radiation pattern, the antenna is cut in half and operates in half-mode. The antenna has a vertical monopole-like radiation pattern in the 2.45 GHz industrial, scientific and medical (ISM) band and a horizontal monopole-like radiation pattern in the 5.8 GHz ISM band. To evaluate the body effect, both 2.45 and 5.8 GHz muscle-equivalent phantoms were used. The overall dimensions of the proposed antenna is 30.5 × 62 × 3.15 mm.

A Novel Design on Compact Slot Antenna with Multi-Band for WiMAX/WLAN Applications

In this paper, a novel coplanar waveguide (CPW)-fed and miniaturized slot antenna for triple-frequency operation is proposed and investigated, which is printed on a small 20mm×20mm FR4 substrate with thickness of 1.0 mm and relative permittivity of 4.3. Through loading different slits, three perfect operating bands of 2.4GHz-2.45GHz, 3.25GHz-4.15GHz and 5.05GHz-6.25GHz are achieved respectively, when return loss is less than-10dB. Experimental results show that the antenna gives monopole-like radiation patterns and good antenna gains over the operating bands. Such antennas is suitable for WLAN 2.4/5.2/5.8 GHz and WiMAX 3.5/5.5 GHz applications.

Substrate integrated waveguide monopolar ring-slot antenna

A single-layer substrate integrated waveguide (SIW) monopolar ring-slot antenna is proposed in this letter. It is based on a combination of a circular ring-slot etched in the SIW top wall and a set of shorting vias placed concentrically between the area bounded by the ring and the SIW bottom wall. Thanks to this configuration, a monopole-like radiation pattern is obtained. The antenna is designed for the 5.8 ISM frequency band, parametrically studied and experimentally verified in free space and in the vicinity of a muscle-equivalent phantom. Experimental results prove that the antenna is very well matched in the 5.8 GHz ISM band, has good radiation performance and small sensitivity to the surrounding environment. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1865–1869, 2014

A NOVEL WIDEBAND SLEEVE ANTENNA WITH CAPACITIVE ANNULUS FOR WIRELESS COMMUNICATION APPLICATIONS

A novel wideband sleeve antenna with capacitive annulus for wireless communication applications is presented in this paper. A sleeve structure is introduced to improve the impedance bandwidth through exciting a new resonate point. By loading capacitive annulus at the center of the sleeve, an impedance bandwidth enhancement is achieved at the upper frequency band. The measured impedance bandwidth for VSWR • 2 about 142.8% ranging from 1.01 to 6.06GHz is achieved, and monopole-like radiation patterns are presented. A prototype has been fabricated and tested, and the experimental results validate the design procedure. It is su-cient for accommodating recent wireless communication services such as DCS1800, PCS1900, IMT2000, WLAN, WiMAX2350/3500, etc.

Switchable Electromagnetic Bandgap Surface Wave Antenna

This paper presents a novel switchable electromagnetic bandgap surface wave antenna that can support both a surface wave and normal mode radiation for communications at 2.45 GHz. In the surface wave mode, the antenna has a monopole-like radiation pattern with a measured gain of 4.4 dBi at ±49° and a null on boresight. In the normal mode, the antenna operates like a back-fed microstrip patch antenna.

A Wide-Bandwidth Monopolar Patch Antenna with Dual-Ring Couplers

A new center-fed circular patch antenna with two coupled annular rings is presented. When the two annular rings are coupled properly, a wide band from 5.45 GHz to 7.16 GHz is achieved with a monopole-like radiation pattern. Measured results show that the antenna with a low profile of 0.027 wavelengths (at 5.45 GHz) has a bandwidth of 27.1% and a measured maximum gain of 6 dBi. The radiation pattern is omnidirectional and remains relatively stable within the operating band.

A NOVEL LOW-PROFILE QUADRIPOD KETTLE ANTENNA WITH ENHANCED BANDWIDTH

The design of a novel low proflle antenna is presented in this paper. By a cross-shaped structure shorted to the ground plane through shorting probes, the size reduction is achieved. A top-loading ring-disc is successfully employed to broaden the impedance bandwidth. Moreover, with the uniformly-arranged shorting pins and a circular sleeve structure placed on the ground, a good omnidirectional performance in the horizontal plane is obtained. An antenna prototype has been implemented and characterized. A measured impedance bandwidth for VSWR • 2 of about 135% ranging from 1500 to 7800MHz is achieved, and a monopole-like radiation pattern is also produced. The height of the proposed antenna is very low with 0:07‚ tall. The proposed antenna is very suitable for indoor base station and the UWB applications.

MINIATURIZED ANNULAR RING SLOT ANTENNA FOR SMALL/MINI UAV APPLICATIONS

A miniaturized annular ring slot antenna is presented. The antenna consists of an annular ring slot structure and a novel folded matching structure. The annular ring slot structure is printed on a substrate and shorted concentrically with a set of conductive vias. The additional matching structure is a ring cavity attached to the back of the annular ring slot structure. Firstly, the diameter of the proposed antenna is reduced by using the folded matching structure comparing with traditional annular ring slot antennas. Secondly, the impedance matching of the proposed antenna is achieved by optimizing the size of the matching structure. A prototype of the proposed antenna with a height of 3.048 mm (0.03λ) and a radius of 47.2 mm (0.4λ) is designed, fabricated and measured. The antenna resonates at 2.67 GHz and has a monopole-like radiation pattern, which shows that the antenna is suitable for the applications of taking off, landing, and long distance communications for a small or mini UAV.

Radiation Efficiency-Improvement Using a Via-Less, Planar ZOR Antenna for Wireless ECG Sensors on a Lossy Medium

The critical issues involving severe radiation efficiency degradations during wireless electrocardiogram (ECG) health monitoring sessions are addressed by devising a monolithic zeroth-order resonance (ZOR) antenna. The presented antenna consists of a composite right/left-handed (CRLH) structure that is realized on a single, planar surface of the flexible printed circuit board (PCB) without the use of any via-holes. This significantly alleviates the complexity and fabrication cost involved with vertically polarized antennas with monopole-like radiation patterns, which are important factors in consumer electronics. Moreover, this letter investigates the practical issues associated with effects of the in-house designed ECG device circuit board, feeding mechanism with the RFIC, as well as the polycarbonate chassis. The finalized antenna is less than 0.12λ×0.08λ in total horizontal dimension with zero height profile. Measurement confirms the presented antenna features more than 30% radiation efficiency across 80 MHz bandwidth when completely integrated within the ECG sensor device and placed on the human body phantom.

DESIGN AND ANALYSIS OF TWO NOVEL CPW-FED DUAL BAND-NOTCHED UWB ANTENNAS WITH MODIFIED GROUND STRUCTURES

In this paper, two novel coplanar waveguide (CPW) fed printed ultra wide band (UWB) monopole antennas with dual band-notching characteristics are proposed. The modifled ground technique with symmetric ground plane in antenna 1 and asymmetric ground planes in antenna-2 is exploited to cover UWB application. Both antennas are compact with dimensions of 30£30£1:6mm 3 and have dual band-notched characteristics with flrst notched band for integrated band of WiMax 3.5/5.5GHz and C-band satellite communications 3.7{4.2GHz and second notched band for WLAN 5.2/5.8GHz bands. Antenna with symmetric ground plane achieves the impedance bandwidth of 2.9{11.5GHz, and antenna with asymmetric ground plane achieves the impedance bandwidth of 2.9{ 11.89GHz, respectively with VSWR < 2 except in the notched bands. The antennas are designed and optimized in CST Microwave Studio. The simulated VSWR of the proposed antenna designs is compared with the measured VSWR of fabricated antennas, and it is found that they are in a good agreement. Both antennas exhibit monopole-like radiation patterns with signiflcant gain in entire operating band. Maximum gain of the proposed antenna with symmetric ground plane is 5.3dBi at 8GHz, and that with asymmetric ground plane is 4.5dBi at 7GHz.

Stacked Equilateral Triangular Dielectric Resonator Antenna Excited With Coaxial Feeding

This paper examines a stack of triangular dielectric resonator antenna which is equilateral in shape. The impedance bandwidth is 16.43% (S11<-10 dB) with wideband monopole-like radiation pattern over the entire band has been examined with 4.987dBi peak gain. The efficient radiation pattern is achieved when the geometry of two equilateral triangular dielectric volume is placed over a ground plane, and using coaxial probe for the excitation. CST (Computer Simulation Technology) Microwave Studio Suite 10 is used for the simulation of the designed antenna. Keywords: Triangular dielectric resonator antenna (TDRA), Dielectric resonator (DR), Impedance Bandwidth (IBW), S11 (S-Parameter), Fractional Bandwidth (FBW), Perfect conductor (PEC).

광대역 특성을 갖는 이중 원형 링 모노폴 안테나의 설계와 제작

본 논문에서는 광대역 특성을 갖는 이중 원형 링 모노폴 안테나를 설계 및 제작 하였다. 제안된 안테나는 평면형 모노폴 형태를 기본으로 이중 원형 링과 접지면으로 구성되어 있으며 광대역 특성을 갖도록 설계하였다. 최적화된 파라메타을 얻기 위해 상용 툴(HFSS)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 적용받는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 제작하였다. 제작된 안테나는 광대역 특성을 갖는 대역에서 반사손실, 이득, 방사패턴의 특성을 측정하였다. 측정결과, -10dB을 기준으로 4,530 MHz(2,510-7,040 MHz)의 광대역 특성을 얻었으며 주어진 이득은 최대이득 0.71~3.38 dBi 그리고 평균이득 -3.85~0.3 dBi을 얻었다. 측정된 방사패턴의 경우, 전체적으로 E면은 전방향성의 방사패턴을 갖고 있으면 H면은 다이폴 안테나의 전형적인 특성을 나타내고 있다 In this paper, a double circular ring monopole antenna for wideband applications is designed and fabricated. The proposed antenna is based on a planar monopole design, and composed of double circular ring of radiating patches and ground plane to obtain the wideband characteristics. To get the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that effect antenna characteristics. Using the obtained parameters, the proposed antenna is fabricated. The fabricated antenna is measured at the operating frequencies, and the return loss coefficient, gain, and radiation patterns are determined. The results of measurement, -10dB impedance bandwidth, measured return loss is 4,530 MHz(2,510-7,040 MHz) and antenna peak and average gains for the frequencies are obtained 0.71~3.38 dBi, -3.85~0.3 dBi, respectively. In case of radiation patterns, the proposed antenna displays nearly omnidirectional radiation characteristics in the E-plane, and monopole-like radiation pattern characteristics in the H-plane.