Ground Plane Size Research Articles

Comparison of Normalized Site Attenuation on Finite Ground Plane

The extent of a rectangular conducting plane for measuring electromagnetic interference is discussed. Mutual coupling between the transmit and receive antennas is negligible, the effects of the ground plane on the normalized site attenuation(NSA) are considered by applying GTD(Geometric theory of diffraction). The calculation was done for the case that measuring distance(d) was 3 m for both horizontal and vertical polarizations. As the result, the size of the rectangular ground plane almost never affects upon NSA for horizontal polarization, but for vertical case, when both width and length of the rectangular plane are several times as long as distance, the effects of the edges are reduced under 1 dB.

COMPACT DUAL BAND PRINTED 2.5-SHAPED MONOPOLE ANTENNA FOR WLAN APPLICATIONS

A novel compact printed antenna for dual band applications is presented. The antenna consists of two monopole elements and operates within the ISM 2.4GHz and 5.2/5.8GHz frequency bands. The proposed antenna provides a bandwidth of 403MHz (2.184GHz{2.587GHz) in the lower frequency band and 4004MHz (3.880GHz{7.884GHz) in the upper frequency band, respectively. Thus, it can cover multiple standards such as: HIPERLAN, 5.5GHz WiMAX, and 2.4/5.2/5.8GHz WLAN. Moreover, the lower resonant frequency of the proposed antenna can be easily tuned within 2.15GHz to 3.22GHz with almost no efiect on the upper resonance. Additionally, the small ground plane size of the proposed antenna makes it suitable for almost any portable device.

A Monocone-Bicone Collinear Array

A wideband monocone-bicone array is designed that has on average 5.5 dB higher gain than a single monocone antenna. The array is fed using a novel feed technique that enables performance similar to that of an ideally fed array. The computed bandwidth that takes into account the radiation pattern stability over a field of view determined by ideal array theory, specifically the radiation pattern of a continuously scaled resonant thin monopole-dipole array is used as a benchmark with respect to which the bandwidth of various monocone-bicone arrays are computed and optimized. Two cost functions are proposed and optimal configurations are determined. It is shown that the antennas maintain performance better than the baseline monopole-dipole array for more than 80% of a 10:1 bandwidth. Methods for feeding the array and mitigating unwanted radiation from the feed network are also explored. Theoretical results are well supported by measurements. The effects of a non-ideal combiner and the finite sized ground plane are also discussed.

Analysis of Ultra-Wideband Printed Planar Quasi-Monopole Antennas Using the Theory of Characteristic Modes

This paper presents an analysis of ultra-wideband (UWB) printed planar quasi-monopole antennas using the theory of characteristic modes. It is shown that the modal voltage-standing-wave ratio, mode current distribution, and modal significance provide deeper physical insight into the operating mechanisms of these popular types of antennas. Using the printed planar bevel-shaped quasi-monopole antenna as an example, we characterize the antenna's performance. It is found that there are only a few significant modes excited. The dominant mode controls the antenna's behavior over the lower band, while the higher-order modes control the behavior over the upper band. The ground-plane size affects the mode properties. The ground-plane height should be taller than a quarter and shorter or equal to a half-guided-wavelength. The width should be equal to a half-guided-wavelength at the lower-frequency edge. We also examine the notched-frequency characteristics of the antenna by embedding a slot in the monopole. We point out the potential self-interference for the first time. Furthermore, we investigate the miniaturization of the antenna by simply chopping off half of the antenna's structure. We explain why the miniaturized antenna exhibits a wider impedance bandwidth and higher cross-polar radiation at higher frequencies.

A Wideband Circularly Polarized H-Shaped Patch Antenna

A wideband H-shaped patch antenna for circular polarization is described. By incorporating a long probe inside a substantial high cavity (~ 0.26λ), a circularly polarized (CP) antenna in broadside direction is achieved. The horizontal arm of the probe is implemented by means of a printed monopole that is diagonally coupled to a small H-shaped copper plate. The CP antenna features a wide operational bandwidth of 19.4%. The maximum gain and the efficiency of this small antenna are recorded as >5 dBic and >80%, respectively, across the bandwidth. The dimension of the H-shaped patch is 0.3λ × 0.3λ whereas the ground plane size is 1.8λ × 1.8λ.

Effect of ground plane size on radiation pattern in IFF/SSR microstrip antenna on thick substrate fed by H type slot

Numerical and experimental study of the effect of the ground plane size on radiation pattern of microstrip antenna on thick substrate is presented in the article. First the results of simulations and measurements of reference microstrip antenna are shown. Next the ground plane sizes were reduced in both x and y directions and the side lobes and backward lobe levels were calculated and measured. It was shown how far we can reduce the size of ground plane without important deterioration of the antenna pattern. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2679–2682, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25568

Efficient high gain with low sidelobe level antenna structures using circular array of square parasitic patches on a superstrate layer

AbstractThis article proposes efficient high gain with low sidelobe level (SLL) antenna structures using circular array of square parasitic patches (CASPPs) for wireless applications. The antenna structure consists of a microstrip antenna that feeds a CASPP fabricated on a low cost FR4 superstrate. The patches on superstrate are suspended in air at about λo/2. The structure with 19‐element CASPPs is designed, fabricated, and tested. The measured VSWR is <2 over 5.725–5.875 GHz frequency band. The antenna with a single square patch provides a gain of 12.6 dB; whereas, the antenna with 19‐element CASPPs provides a gain of 18.3 dB with 93.4% efficiency, SLL of −26.1 dB, and front to back lobe ratio of >20 dB. Antenna with CASPPs on finite ground requires 25% less ground plane size as compared to planar array. The proposed structure can be packaged inside an application platform. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2812–2817, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25613

A Wideband Aperture-Coupled Microstrip Patch Antenna Employing Spaced Dielectric Cover for Enhanced Gain Performance

A dielectric cover is used to enhance the gain of an aperture-coupled microstrip patch antenna. The cover is spaced off of the patch antenna by air and, as expected, is found to significantly increase antenna broadside directivity in some configurations. A parametric study on the effects of spacing height, cover size, and thickness of the cover are presented. This study uses a finite element method (FEM) based, commercial analysis tool to perform these parametric searches, and so accounts for finite size ground planes and dielectrics. The previous research work reported in literature considered infinite-area ground planes and dielectrics. The wide impedance matching bandwidth of the aperture-coupled microstrip patch also allows observation of the narrow-bandwidth effects of the added dielectric cover. Finally, a proposed design methodology is outlined, and a prototype of the antenna was fabricated and experimentally verified with a peak gain of 13.9 dBi. The measured results agree reasonably well with the simulated ones.

FSS 구조를 이용한 Cavity-Backed 고이득 이중 대역 마이크로스트립 안테나 설계

본 논문에서는 Frequency Selective Surface(FSS)를 이용하여 IEEE 802.11a/b 대역에서 11 dBi 이상의 이득과 유사한 모양의 복사 패턴을 가지며 동작하는 cavity-backed 이중 대역 마이크로스트립 안테나를 제안한다. 안테나의 크기는 <TEX>$71.5{\times}42.0{\times}6.6\;mm^3$</TEX>이고, FSS의 크기는 <TEX>$120.0{\times}120.02\;mm^3$</TEX>, 그리고 cavity를 포함한 접지면의 크기는 <TEX>$150.0{\times}145.0\;mm^3$</TEX>이다. 안테나는 동축 케이블을 이용하여 급전하였으며, 안테나와 FSS는 비유전율이 3.38인 RO4003 기판 위에 설계하였다. 전산 모의 실험 결과, VSWR<2 기준으로 2.369~2.517 GHz와 5.608~5.833 GHz의 대역폭을 가지며, 각 대역의 중심 주파수에서의 이득은 11.23 dBi와 12.60 dBi다. In this paper, a cavity-backed high gain dual band microstrip antenna with Frequency Selective Surface space(FSS) for WLAN is proposed. The proposed antenna that operates in IEEE 802.11a/b bands with similar radiation pattern and gain is fabricated on RO4003 substrate with a dielectric constant of 3.38. The size of the antenna is <TEX>$71.5{\times}42.0{\times}6.6\;mm^3$</TEX>, and the FSS size is <TEX>$120.0{\times}120.02\;mm^3$</TEX>. The ground plane size including cavity is <TEX>$150.0{\times}145.0\;mm^3$</TEX>. The antenna is fed by coaxial cable. The simulated bandwidths of the antenna are 2.369~2.517 GHz and 5.608~5.833 GHz for VSWR<2. The gains are 11.23 dBi and 12.60 dBi, respectively, for the lower and upper bands.

A REFLECTARRAY ANTENNA BACKED ON FSS FOR LOW RCS AND HIGH RADIATION PERFORMANCES

This paper investigates the application of frequency- selective surface (FSS) in re∞ectarray antennas for the purpose of reducing radar cross section (RCS) level. Difierent from previous reports, the presented band-stop FSS structure is also characterized by the suppression of surface waves, which makes a contribution to better radiation performance. Two 14£14 re∞ectarray antennas backed on the FSS ground and a solid ground are designed and fabricated. Simulated and measured results show that the FSS ground can improve the 'in- band' gain by 1.1dB, decrease the sidelobe level by 6.4dB, and reduce the 'out-of-band' RCS efiectively when compared with the antenna with a solid ground plane of the same size.

Radiation properties and ground-dependent response of compact printed sinusoidal antennas and arrays

Printed sinusoidal monopoles are enhanced meander-line antennas (MLAs). The antennas were designed in the 2.0–3.5 GHz band according to the size and bandwidth constraints of high data-rate wireless sensor nodes. Their performance was characterised in terms of electrical size, bandwidth and broadband radiation efficiency. A suitable scalar quantity was used to capture the overall performance. Numerical results show that sinusoidal monopoles can achieve 50% fractional bandwidth (FBW), which is a 60% improvement compared to an MLA of similar size and efficiency. Antenna performance depends heavily on electrical size, which depends on the size of the ground plane; its effect on radiation was also included. Compact printed arrays built with sinusoidal monopoles were also studied. Their performance was characterised in terms of active impedance bandwidth, broadband radiation efficiency, active element pattern, mutual coupling and broadband correlation coefficient. The results showed that densely packed compact arrays feature controllable element detuning, whereas correlation coefficient stayed below 0.5 even for λ/10 spacing. The computational results were supported by measurements on actual hardware. Antennas mirrored against the nominal 20 mm×30 mm ground plane achieved FBWs in the range 23–28%. Those that used the adapted ground plane (GNDP) size scored 24–34% FBWs. In the case of arrays, the active impedance FBW degraded gracefully with decreasing inter-element distance from 33% to 27%.

Print a Compact Single- and Quad-Band Slot Antenna on Ceramic Substrate

A miniaturized slot antenna is designed on the 0.4 mm-thickness Al2O3 ceramic substrate with ground plane size of 30 mm × 30 mm and the printed method is used to get the designed patterns. Two different strip insets, U-shape and N-shape, are added in the slot to improve the characteristics of microstrip fed antennas. When a symmetrical U-shaped strip inset is added in the slot, the fabricated antenna reveals a single-band characteristic and has a relatively large return loss of –28.0 dB at 3.12 GHz and a wide –10 dB impendence bandwidth of 8.9% (275 MHz). When an un-symmetrical N-shaped strip inset is added, the antenna reveals the quad-band characteristics with the resonant frequencies at 2.22 GHz, 3.23 GHz, 4.63 GHz, and 5.42 GHz, respectively. The gains and far-field radiation patterns of the N-shaped antenna are also developed in this study.

Bandwidth enhancement, radiation properties and ground-dependent response of slotted antennas integrated into wireless sensors

The design of low-cost, wideband, printed inverted-F antennas (PIFAs) that are suitable for portable devices operating at the 2–3 GHz band is described. The design specifications were extracted according to the constraints of high data rate wireless sensor devices. Reactive tuning through slot loading was applied to enforce degeneration of a higher resonance, and thus double the bandwidth in the band of interest. Three slotted antenna configurations are reported plus a baseline configuration; a thorough numerical characterisation of performance is provided. Fractional bandwidth (FBW) in the range 22–34% was achieved, which is almost quadruple that of existing implementations. The antennas exhibit total efficiencies around 80% and are elliptically polarised. A suitable figure-of-merit is suggested for performance comparisons; it attempts to capture overall antenna performance in a single quantity. Antenna performance depends heavily on electrical size, which depends on the size of the ground plane, since the RF ground is an integral part of the total radiator. The ground-effect study showed that wrong choice of size can force resonant modes to vanish. Best performance for a slotted PIFA was obtained with a ground plane measuring 0.20λ×0.28λ, significantly smaller than predicted in prior studies. Bandwidth augmentation through slot loading is supported by measurements. Fabricated antennas with sub-optimal ground plane sizes exhibit FBWs in the range 20–23%.

Design of Rectangular Dielectric Resonator Antenna Fed by Dielectric Image Line with a Finite Ground Plane

A Rectangular Dielectric Resonator Antenna (RDRA) fed by Dielectric Image Line (DIL) through a narrow slot placed on a finite ground plane is numerically investigated. The effects of ground plane size on the radiation performance of the antenna are carried out. To increase the antenna gain, four sidewalls are placed around the corners of the ground. Also, a reflector is placed at the back side of the structures to reduce backward radiation. Results show that 7.7 dB gain is obtained at 10 GHz with a broadside radiation pattern. For the DRA with four sidewalls maximum gain of 10.4 dB at 10.4 GHz is achieved which is 2.7 dB higher than the gain of the structure without them. The effect of air gap between dielectric resonator and ground plane is also investigated. The results show that with increasing the distance between the DR and ground, antenna gain is decreased.

A COMPACT PLANAR HEXA-BAND INTERNAL ANTENNA FOR MOBILE PHONE

A planar hexa-band internal antenna designed for mobile phone applications is presented. The antenna occupying a small area of 45 £ 12mm 2 is placed on the top no-ground portion of the system circuit board with a ground-plane size of 45 £ 100mm 2 . The design begins with constructing a meandered monopole. With a parasitic and an impedance-adjustment structure subsequently added, the resulting antenna can be viewed as a printed planar inverted-F antenna with a parasitic resonant element. Two wide impedance bands can be generated by the designed antenna to support GSM 850, GSM 900, DCS, PCS, UMTS, and 2.4-GHz WLAN operations. The measurement was found to agree reasonably well with the simulation. Design procedures and rules along with the design concepts behind are all presented in detail.

The Significance of Ground-Plane Size and Antenna Location in Establishing the Performance of Ground-Plane-Dependent Antennas

The performance properties of small, multi-band, device-integrated antennas are significantly affected by the ground-plane structure on which they are mounted. In many cases, the time-varying current on the ground plane is the primary source of radiation that determines both the antenna's impedance and radiation-pattern properties. With device-sized or integrated antennas, it is sometimes presumed that the primary factor affecting or establishing the antenna's performance is the significantly reduced size of the ground plane. Here, we consider both the ground plane's size and the location of the antenna on the ground plane in terms of how these factors affect the antenna's performance. We demonstrate that often, it is the location of the antenna and its feeding point on the ground plane, rather than the size of the ground plane itself, that primarily establishes the antenna's performance in terms of its impedance, bandwidth, and radiation mode. We also show that in many cases, the method used to feed the antenna and how the feed couples to the ground plane can be significant factors in establishing the current distribution on the ground plane, and therefore the antenna's performance. We demonstrate these effects for several single and multi-band antenna designs.

A Yagi–Uda Array of High-Efficiency Wire-Bond Antennas for On-Chip Radio Applications

In this paper, we present a high-efficiency nonplanar Yagi-Uda antenna array consisting of six wire bonds for on-chip radio applications. The measured and simulated results are presented for the radiation pattern, gain, and radiation efficiency of the antenna at 40 GHz. The array has been characterized with two different ground-plane sizes that are 0.32¿ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 1.4¿ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The arrays achieved the measured gains of 6.0 and 8.1 dBi for the small and large ground-plane variations, respectively, after numerically removing the loss from the feed line. The efficiencies of the antennas were extracted using the simulated directivity values. The efficiency of the large ground antenna was 82.5%, whereas that of the small ground antenna was 72.0%. Single wire-bond antennas are also characterized when integrated directly on a silicon-germanium complementary-metal-oxide-semiconductor transceiver chip with -1.4-dBi gain and 51% efficiency. This paper builds on measurements of a single wire-bond antenna over ground-plane sizes ranging from 0.5¿ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> to 2.1¿ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which achieved gains of 0.4-3.6 dBi and efficiencies of 51%-84%.

Meandered T-Shaped Monopole Antenna

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A simple dual band monopole antenna for 2.45/5.2/5.8 GHz LAN operations built on a single layer FR4 substrate is investigated. It is configured as an asymmetrical meandered T-shaped monopole with a long and a short arm. Depending on relative length of the two arms, the short arm can be used to tune the resonant frequency and/or the bandwidth. Bandwidth enhancement is also achieved by tuning the ground plane size. </para>

Soft Surface를 이용한 신호 중계 장치용 이중 대역 마이크로스트립 안테나

본 논문에서는 soft surface를 이용하여 IEEE 802.11a/b 대역에서 10 dBi 이상의 이득과 유사한 모양의 복사 패턴과 이득을 가지며, 동작하는 신호 중계 장치용 안테나를 제안한다. 제안한 안테나의 크기는 <TEX>$50{\times}56.5{\times}5.5\;mm^3$</TEX>이고, soft surface를 포함한 접지면의 크기는 <TEX>$175.0{\times}154.4\;mm^2$</TEX>이다. 안테나는 동축 케이블을 이용하여 급전하였으며, 두께가 0.508 mm이고 비유전율이 3.38인 RO4003 기판 위에 설계하였다. 전산 모의 실험 결과, VSWR<2 기준으로 2.388~2.493 GHz와 5.561~6.051 GHB의 대역폭을 가지며, 각 대역의 중심 주파수에서의 이득은 10.63 dBi와 10.33 dBi이다. In this paper, a dual band microstrip antenna with soft surface for gapfiller applications is proposed. The proposed antenna with similar radiation pattern and gain is fabricated on RO4003 substrate with a dielectric constant of 3.38 and a thickness of 0.508 mm, and operates in IEEE 802.11a/b bands. The size of the antenna is <TEX>$50{\times}56.5{\times}5.5\;mm^3$</TEX> and the ground plane size including soft surface structure is <TEX>$175.0{\times}154.4\;mm^2$</TEX>. The antenna is fed by coaxial cable. The simulated bandwidths of the antenna are 2.388~2.493 GHz and 5.561~6.051 GHz for VSWR<2. The gains are 10.63 dBi and 10.33 dBi, respectively, for the lower and upper bands.

Effect of superstrate material on a high‐gain antenna using array of parasitic patches

AbstractThis article highlights the effect of superstrate material on a high‐gain antenna using array of parasitic patches for wireless applications. The antenna structure consists of a microstrip antenna, which feeds an array of square parasitic patches fabricated on a ceramic or FR4 superstrate. The patches on a superstrate are suspended in air at λ0/2. The spacing between parasitic patches and patch dimensions decrease with dielectric constant and, thus, a compact antenna with almost same gain can be designed with high dielectric superstrate. The structures with 5 × 5 array of square parasitic patches provide a gain of 17.5 dB on infinite ground plane in both the cases but the array dimension is 55 × 55 mm2 in ceramic as compared to 115 × 115 mm2 Antenna with ceramic superstrate on finite ground requires 25% less ground plane size as compared to FR4. Structure with FR4 superstrate is designed, fabricated, and tested. The measured VSWR is &lt;2 over 5.725–5.875 GHz frequency band. The antenna with 5 × 5 array of square parasitic patches provides a gain of 18.0 dB with 92% efficiency, SLL of −18.4 dB, and front to back lobe ratio of more than 20 dB. The proposed structure can be packaged inside an application platform. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 82–88, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24850