Planar Monopole Research Articles

Miniaturized Double-Layer EBG Structures for Broadband Mutual Coupling Reduction Between UWB Monopoles

Novel miniaturized two-layer electromagnetic band gap (EBG) structures are presented for reducing the electromagnetic coupling between closely spaced ultra wideband (UWB) planar monopoles on a common ground. The proposed EBG structures employ two closely coupled arrays, one comprising linear conducting patches and the other comprising apertures (slits) in the ground plane. The two arrays are printed on either side of a very thin dielectric layer (55 μm) with a rotation between the elements to produce maximum coupling for miniaturizing. A microstrip line excitation is initially used for the efficient analysis and design of the slit-patch EBG structures, which are subsequently employed between two UWB printed monopoles. The proposed EBG structure has a small footprint and produces a significant reduction of the mutual coupling across the wide operating band of the UWB antennas. Simulated results and measurements of fabricated prototypes are presented.

Multiband planar monopole antenna using coupling control feed structure for mobile handsets

ABSTRACTIn this article, a planar monopole antenna very close to the ground plane of mobile handsets is presented. Multiband operation is achieved by controlling the magnetic coupling between the feed structure and antenna structure with a slot structure and inductor. Measurements demonstrate that the proposed antenna possesses frequencies of 228 MHz (813–1041 MHz) and 601 MHz (1643–2244 MHz) with a voltage standing wave ratio of three even though the size of the proposed antenna is only 60 × 7 mm2. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:823–826, 2015

A Simple Planar Polarization Reconfigurable Monopole Antenna for GNSS/PCS

The design of a simple planar polarization reconfigurable monopole antenna for the Global Navigation Satellite System (GNSS) and Personal Communications System (PCS) is presented. The antenna consists of two meandered monopoles, a feeding network using the Wilkinson power divider, two switchable 90 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{0}$</tex></formula> -phase shifters implemented using <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\lambda/4$</tex></formula> -microstrip lines and a defected ground structure (DGS). The meandered monopoles resonating at about 1.55 GHz are placed perpendicular to each other. The input signal is divided into two signals with equal amplitude and phase by the power divider and fed to the meandered monopoles via the phase shifters. The two signals arriving at the two monopoles have a phase difference of 90 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{0}$</tex></formula> , <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$-90^{0}$</tex></formula> or 0 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{0}$</tex></formula> , depending on the phase shifters controlled using six PIN-diode switches, hence generating a right/left-handed circularly polarized (CP) or linearly polarized (LP) signal. We propose a novel biasing technique to control the six PIN diodes using five voltages. Measurement results show that the antenna in CP has an impedance bandwidth <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$({\rm S}11 &lt; -10 ~{\rm dB})$</tex></formula> of 1.06-1.64 GHz and an axial-ratio bandwidth <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$({\rm axial-ratio}&lt; 3~{\rm dB})$</tex></formula> of 1.43-1.84 GHz, and in LP has an impedance bandwidth of 1.63-1.88 GHz. Simulated and measured results on S11, AR, radiation pattern, and gains show good agreements.

Compact planar ultra‐wideband antenna with quintuple band‐notched characteristics

A compact ultra-wideband planar monopole antenna with a size of 22 mm by 34 mm is presented to achieve the quintuple-band-notched characteristics. The proposed antenna consists of a Mickey-mouse shaped radiating element, a truncated/smoothed ground plane and a microstrip feed-line. The quintuple-band-notched function is achieved by integrating five specially designed half/one-wavelength M-shaped resonators into the radiator, feed-line and ground plane. The simulated and measured results show that the proposed antenna is able to operate from 2.24 to 10.8 GHz for |S11| < −10 dB with excellent band rejection performance in the frequency bands of 2.35 to 2.61 GHz, 3.16 to 3.69 GHz, 5.0 to 6.1 GHz, 7.2 to 7.7 GHz and 8.1 to 8.74 GHz for some existing communication systems such as wireless local area networks, worldwide interoperability for microwave access, downlink of X-band satellite communication and ITU 8-GHz band, respectively. In addition, both the frequency-domain and time-domain performances of the antenna are investigated by simulation and measurement. The results obtained are also in very good agreement.

Compact U‐shape radiating patch with rectangular ground planar monopole antenna

A compact U-shape radiating patch with rectangular ground planar monopole antenna is proposed. Antenna is fabricated on FR4 substrate with permittivity 4.4 and loss tangent 0.02 with dimension 75(LR) × 48(WR) × 1.6(h) mm3. Measured return loss is ≤ −10 dB for the entire impedance bandwidth (800–3500 MHz). In addition, different key parameters which affect the impedance bandwidth are analysed and results discussed. Moreover, antennas have acceptable gain flatness with good omnidirectional radiation patterns. Its ease of fabrication, compatibility with other electronic devices, and radiation pattern make it a competent candidate for global system of mobile (890–960 MHz), digital communication system (1700–1900 MHz) and Bluetooth (2.45 GHz) cellular communication applications.

ISM 2.45GHz/5.8GHz 이중대역 특성을 위한 십자형 평판 모노폴 안테나의 구조 변경

ABSTRACT This study presents the structure design of antenna to have the dual band characteristics in a desired frequency band through the structural modification of an antenna structure. For the experiment, a wideband crossed planar monopole antenna was used. The target frequency band was set to ISM 2.45GHz/5.8GHz. To give the properties, an additional antenna element was added to the crossed planar monopole antenna, which is a main body of the antenna. And then structural adjustment parameter was set to change the length(shape) of the antenna. Various simulations were conducted to find the dual band characteristics in the desired frequency band. The simulations brought forth the antenna bandwidth above the normal values for ISM 2.45GHz/5.8GHz. The structural adjustment parameter introduced in this study for structural modification of an antenna can be useful in developing an antenna featured with dual band(multiband) characteristics. 키워드 : 십자형 평판 모노폴 안테나, 구조 변경, 조정변수, 이중대역 Key word :

고투자율 자성기판을 이용한 광대역 안테나 격리도 특성 개선

본 논문에서는 고투자율 자성기판을 이용한 광대역 안테나 격리도 특성 개선방법을 제안하였다. 제안된 안테나는 평판형 모노폴 안테나의 근접 자계 분석을 바탕으로 고투자율 자성기판을 안테나에 삽입한 형상이며, 동작주파수에서의 안테나 성능을 유지하고, 차단 주파수에서의 간섭을 최소화하여 근접한 안테나와의 격리도 특성을 개선한다. 격리도 개선을 확인하기 위해 동작주파수 2 GHz인 기준 모노폴 안테나를 설정하여 제안된 안테나와 기준 안테나의 <TEX>$S_{21}$</TEX>을 자성기판 삽입 전후로 측정하였다. 그 결과, 기존 안테나의 동작 성능은 유지하며, 2 GHz 이상의 차단 주파수에서 <TEX>$S_{21}$</TEX>이 5~10 dB 이상 개선되었으며, 고투자율 자성기판을 이용하여 안테나의 격리도 특성 개선이 가능함을 확인하였다. In this paper, we propose a method of isolation improvement for broadband antennas using a high-permeability substrate. The substrate is applied for a planar monopole antenna based on near-field analysis to maintain radiation characteristics at its operating frequency while improving isolation by minimizing mutual coupling with nearby antennas at other frequency bands. To verify isolation improvement, we compare performance variations of <TEX>$S_{21}$</TEX> according to the existence of the substrate using the proposed antenna and a reference antenna whose operating frequency is 2 GHz. As a result, the radiation characteristics are maintained, and <TEX>$S_{21}$</TEX> performance is improved by more than 5~10 dB in the frequency band of greater than 2 GHz, which demonstrates the isolation can be improved by using the high-permeability substrate.

A hybrid integrated ultra-wideband/dual-band antenna with high isolation

In this paper, we propose a novel integrated ultra-wideband (UWB) monopole antenna with dual-band antenna. The antenna consists of planar rectangular with semi-elliptical base and a rectangular dielectric resonator antenna (DRA) with dual-band operation. Both of them are excited via coplanar waveguide (CPW) lines. The experimental measurements show that the planar monopole provides an impedance bandwidth between 2.44 and 11.9 GHz which largely covers the entire UWB spectrum, and the rectangular DRA operates at two bands; 5.3–6.2 and 8.5–9.4 GHz. Additionally, the proposed structure ensures low mutual coupling between the two ports (with S21 less than −20 dB in the whole operating frequency band). The measured and numerical results show a good agreement.

Planar monopole antenna with a compact radiator for tri-band applications

A novel planar monopole antenna with a compact radiator is proposed for tri-band operation. The antenna consists of double C-shaped monopole strips and an inverted U-shaped shorted strip to generate three resonant modes. The radiator of the antenna occupies a small size of 9 × 14.8 mm2. By optimizing the designed parameters of the radiator, good impedance matching can be obtained over the three desired bands. The prototype of the designed antenna is fabricated and tested. Measured results show that the antenna has 10-dB return loss impedance bandwidths of 340 MHz (2.39–2.73 GHz), 560 MHz (3.23–3.79 GHz), and 910 MHz (5.05–5.96 GHz), which can cover both 2.4/5.2/5.8 GHz wireless local area network and 2.5/3.5/5.5 GHz worldwide interoperability for microwave access operating bands. The features of compact size, simple structure, and good tri-band performance make the antenna a promising candidate for practical wireless applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:706–709, 2015

A Triple-Band Monopole Planar Antenna for WLAN and WiMAX Applications

AbstractIn this letter, a compact monopole planar antenna with inverted F- and L-shaped strips is presented for WLAN and WiMAX applications. By adjusting the geometries and the sizes of the strips, the proposed antenna can achieve triple-band performance covering three separated impedance bandwidths of 300 MHz (2.2–2.5 GHz), 400 MHz (3.3–3.8 GHz), and 800 MHz (5.1–5.9 GHz), which are well applied for both 2.4/5.2/5.8-GHz WLAN bands and 3.5/5.5-GHz WiMAX bands. The overall dimension of the proposed antenna can reach 20 × 25.5 mm

Bandwidth enhancement of capacitive fed monopole antenna using parasitic patches

This paper proposed a compact planar monopole antenna operating at 5 GHz (5.180–5.825 GHz) industrial, scientific and medical (ISM) radio band. The antenna constructed with 20 mm × 12 mm radiating element and 25 mm square of the ground plane in FR4 substrate provided −10 dB bandwidth of 1 GHz (5.4–6.4 GHz). To improve the bandwidth, parasitic elements are added with the monopole antenna. A capacitive feed is also incorporated in the design. It observed that the proposed antenna with parasitic elements provides a larger impedance bandwidth of about 3 GHz (5.1–8.1 GHz), which is three-fold improvements over the one without parasitic patches. The prototype of the antenna that operates at 5.8 GHz frequency range is fabricated and characterized using a near-field measurement system. A good agreement is found between the simulation and measured results.

A Triple Band Notch Compact UWB Printed Monopole Antenna

A compact ultra-wideband planar monopole antenna with triple band-notched characteristic is proposed. The antenna consists of a rectangular patch with two bevels. To realize notch characteristics in 3.3---3.7 GHz for WiMax, and in 5.15---5.85 GHz for WLAN band, two round shape slots are etched in radiating patch. The third notch band in 7.1---7.76 GHz for X-band downlink satellite communication is obtained by etching a pair of C-shaped slot on the ground. The proposed antenna exhibits a nearly omnidirectional radiation pattern in the $$H$$H-plane, and a dipole-like radiation pattern in the $$E$$E-plane for the entire pass band. The proposed antennas are successfully simulated and measured. The individual effects of the each slot on band notch characteristics are also investigated. The gain of the proposed triple band notched antenna is relatively stable across the operating frequency band except at notched bands and thereby making the proposed antenna suitable for practical UWB applications.

PLANAR MONOPOLE UWB ANTENNA FOR USB DONGLE APPLICATION

In this communication, a systematic approach for design of planar monopole ultra-wideband (UWB; 3.1 ∼ 10.6 GHz) antenna for wireless USB dongle has been proposed. The simple planar monopole antenna consists of a rectangular metallic radiating patch whose modal analysis is carried out first by means of the Theory of Characteristic Modes (TCM), in order to identify the different radiating modes and get the physical insights of these radiating modes of the antenna. Further, based on the physical evidences obtained from the radiating modes of the similar planar monopole antenna, a bevel transition feed with rectangular slot has been used to enhance the bandwidth and obtain the desired radiation characteristics of the proposed antenna. The modal analysis is carried out using characteristic modes (CM) analysis tool in CADFEKO 7.0 simulation software. The proposed antenna exhibits a very compact dimensions of 12 mm × 16 mm × 5 mm and yields a good insights in simulated and measured impedance bandwidth of 3.1 ∼ 12 GHz with VSWR < 2. Furthermore, the proposed antenna exhibits symmetrical radiation patterns, stable-high gain and efficiency and ultra-wide bandwidth making it suitable candidate for practical UWB-USB applications.

Frequency- and Pattern-Reconfigurable Antenna for Multistandard Wireless Applications

A printed antenna with frequency and pattern reconfiguration is presented in this letter to meet the requirements of IEEE 802.11a/b/g/n and 802.16 standards. By controlling five p-i-n diodes, the antenna can be considered as a planar monopole or a microstrip patch and has three operation modes, i.e. an omnidirectional pattern mode at the lower frequency band of 2.21–2.79 GHz, a unidirectional pattern mode at the higher frequency band of 5.27–5.56 GHz, and both of them working simultaneously. It provides a low-profile, low-cost, and reconfigurable solution for multistandard wireless communication applications.

A Low-Profile, Low-Backlobe and Wideband Complementary Antenna for Wireless Application

A new complementary antenna (or Huygens source) with a very low profile is presented. This antenna, composed of a pair of planar monopoles, a pair of bowtie shaped slots and a microstrip antenna, provides a broadband operation while its height is only $0.035 \lambda_{{{0}}}$ , where $\lambda _{{{0}}}$ is the wavelength referring to the center frequency of the operating band. More importantly, the proposed antenna radiates unidirectionally without the need of a metallic reflector. And therefore the total antenna volume is reduced to $0.011 \lambda _{{{0}}}^{{{3}}}$ . A prototype was fabricated and measured. It exhibits an impedance bandwidth $({\rm SWR} \leq 2)$ of 20.7% from 1.387 GHz to 1.696 GHz, a stable boresight gain of 6.11 dBi and a unidirectional radiation pattern with low back radiation ( ${ dB), low cross-polarization ( ${ dB).

Effect of Metal and Magnetic Slab on Radiation Characteristics of Monopole Antenna

The effect of metal and magnetic slab on the radiation characteristic of monopole antenna is studied in this paper. The presence of metal slab changes the antenna radiation pattern and it also increases the gain up to 4.6 dB. The radiation characteristic of monopole antenna is determined by the separation distance between planar monopole and metal slab. In addition, magnetic slab also changes the antenna radiation pattern and it also increases the gain up to 3 dB. Metal slab makes antenna generate reflection, but magnetic slab makes antenna generate refraction is their difference. As to the application slab, the initial pattern of the antenna without materials was omnidirectional. However, when the materials were added, its pattern would change, making the antenna to have other usages and transition effect. They will influence electromagnetic in power systems.

An Ultrawideband to Dual-Band Switchable Antenna Design for Wireless Communication Applications

A switchable planar monopole antenna operating in ultrawide band (UWB)and dual-band mode is demonstrated. The switching is triggered with a photoconductive semiconductor switch triggered by light emitting diode. In the switched-off state, the antenna operates in the dual-band/UWB mode, while in the switch-on state the configuration converts to a dual-band antenna due to the extended ground plane. The measured and simulated results show that the dual-band/UWB mode entirely covers the UWB frequency band and the 2.4 GHz wireless local area network WLAN, while the dual-band mode represents a dual-band antenna operating at WiMAX and X-band Satellite communication bands.

WIDEBAND PRINTED PLANAR MONOPOLE ANTENNA FOR PCS, UWB AND X-BAND APPLICATIONS

In this paper, a printed planar monopole antenna (PPMA) is presented for PCS, UWB and X-band. The antenna is designed in two stages. In the design of the preliminary PPMA used to obtain the proposed PPMA, the structure is divided into sections, and they are optimized in the sense of bottom to up strategy. The bandwidth is enhanced by employing tapered transitions and inset feed. The resulting antenna operates between 2.37GHz and 12GHz with VSWR < 2 and an average peak realized gain of 4.95 dB. Therefore, the preliminary antenna can be considered to be suitable for Bluetooth, WLAN, WiMAX, UWB and X-band. The proposed PPMA is designed by implementing slots on the preliminary PPMA to include PCS, and to suppress Bluetooth and commonly used WLAN and WiMAX bands, the ones allocated out of UWB. The proposed antenna operates in the 1.67GHz– 1.91GHz and 3GHz–15GHz bands with VSWR < 2. The peak realized gain (Gpr) in PCS is 1.32 dB at 1.8GHz, and the average Gpr is 5 dB for the 3GHz–15GHz band. The group delay performances are also examined, and the maximum group delay deviations of preliminary and proposed PPMAs are observed as 1 ns and 1.25 ns, respectively.

Wideband Planar Monopole Antennas for the Brazilian Digital TV System

This paper presents the design, construction and measurements (both at device and system level) of two different planar monopole antennas for the use in the receiving site of a Brazilian Digital TV System, operating in Ultra-High Frequency Range. The design goals were towards low cost, robustness and small volume antennas, for indoor applications and with good performance in terms of return loss within the frequency band. The antennas were designed and optimized using a full wave electromagnetic solver and had their performance compared to an ordinary wire monopole. The scattering parameters were simulated and measured as well as their performance when connected to a digital TV tuner and to a spectrum analyzer, in a dense urban indoor environment was evaluated, as well.

Inkjet-Printed Wideband Planar Monopole Antenna on Cardboard for RF Energy-Harvesting Applications

We present a fully inkjet-printed novel wideband planar monopole antenna on thin packaging cardboard available in bulk for low-cost and environmentally-friendly mass manufacturing. We outline the characterization and the dielectric properties of the cardboard that are imperative for the successful design of an antenna on a paper-based substrate. To achieve highly conductive inkjet-printed pattern on the fibrous and porous cardboard, we deposit thin dielectric coating on the cardboard in the same inkjet process. The operation of the antenna is attested through simulations and measurements in the frequency range of 600-1500 MHz, where there are several strong radio signals present for ambient RF energy harvesting.