Showing papers on "Folded inverted conformal antenna published in 1995"
TL;DR: In this article, a coaxially-fed single-layer single-patch wideband microstrip antenna in the form of a rectangular patch with a U-shaped slot is discussed, achieving 10-40% impedance bandwidth without the need of adding parasitic patches in another layer or in the same layer.
Abstract: A coaxially-fed single-layer single-patch wide-band microstrip antenna in the form of a rectangular patch with a U-shaped slot is discussed. Measurements showed that this antenna can attain 10-40% impedance bandwidth without the need of adding parasitic patches in another layer or in the same layer.<
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742 citations
01 Jan 1995
TL;DR: In this article, the authors investigated the effect of the tissue location and physical model on the antenna performance and found that the head and hand absorb between 48 and 68% of the power delivered to the antenna.
Abstract: In personal communications, the electromagnetic interaction between handset-mounted antennas and the nearby biological tissue is a key consideration. This paper presents a thorough investigation of this antenna-tissue interaction using the finite-difference time-domain (FDTD) electromagnetic simulation approach with detailed models of real-life antennas on a transceiver handset. The monopole, side-mounted planar inverted F, top-mounted bent inverted F, and back-mounted planar inverted F antennas are selected as representative examples of external and internal configurations. Detailed models of the human head and hand are implemented to investigate the effects of the tissue location and physical model on the antenna performance. Experimental results are provided which support the computationally obtained conclusions. The specific absorption rate (SAR) in the tissue is examined for several different antenna/handset configurations. It is found that for a head-handset separation of 2 cm, the SAR in the head has a peak value between 0.9 and 3.8 mW/g and an average value between 0.06 and 0.10 mW/g for 1 W of power delivered to the antenna. Additionally, the head and hand absorb between 48 and 68% of the power delivered to the antenna. >
479 citations
15 Feb 1995
TL;DR: A microstrip reflectarray is a flat reflector antenna that can be mounted conformally onto a spacecraft's outside structure without consuming a significant amount of spacecraft volume and mass.
Abstract: A microstrip reflectarray is a flat reflector antenna that can be mounted conformally onto a spacecraft's outside structure without consuming a significant amount of spacecraft volume and mass For large apertures (2 m or larger), the antenna's reflecting surface, being flat, can be more easily and reliably deployed than a curved parabolic reflector This article presents the study results on a microstrip reflect-array with circular polarization Its efficiency and bandwidth characteristics are analyzed Numerous advantages of this antenna system are discussed Three new concepts using this microstrip reflectarray are also proposed
145 citations
TL;DR: In this paper, an inverted F antenna loaded with a very high permittivity substrate has been demonstrated to reduce the size of the antenna without sacrificing the antenna radiation efficiency, and the gain-enhancement mechanism, bandwidth, and antenna radiation gain and patterns are presented and discussed.
Abstract: Enhanced gain of an inverted F antenna loaded with a very high permittivity substrate has been demonstrated. Measurements show that the size of the antenna can be reduced without sacrificing the antenna radiation efficiency. The gain-enhancement mechanism, bandwidth, and antenna radiation gain and patterns are presented and discussed.
130 citations
TL;DR: In this article, a simple algebraic formula for the resonant frequency of a circular microstrip disk antenna as a function of the effective radius and of the fringing capacitance has been derived which is valid for electrically-thick dielectric substrates.
Abstract: A simple algebraic formula for the resonant frequency of a circular microstrip disk antenna as a function of the effective radius and of the fringing capacitance has been derived which is valid for electrically-thick dielectric substrates. Accuracy of the theoretical results of resonance is compared with previous theories and measured data. >
55 citations
TL;DR: In this article, a flexible ribbed antenna is modeled and controlled using an identified MIMO minimum-order model of the antenna, which is synthesized from identified single-input, single-output transfer functions curve fit in the frequency domain.
Abstract: Theoretical and experimental results of the modeling and control of a flexible ribbed antenna are presented. The antenna consists of eight flexible ribs that constitute an active antenna in the sense that the actuators and sensors are an integral part of the structure. The antenna exhibits closely spaced and repeated modes, thus multi-input, multi-output (MIMO) control is necessary for controllability and observability of the structure. The structure also exhibits a mode localization phenomenon and contains postbuckled members making an accurate finite element model of the structure difficult to obtain. An identified MIMO minimum-order model of the antenna is synthesized from identified single-input, single-output transfer functions curve fit in the frequency domain. The identified model is used to design a positive position feedback and //oo controller that increases damping in all of the modes in the targeted frequency range. Because of the accuracy of the open-loop model of the antenna, the closed-loop response predicted by the identified model correlates well with experimental results.
51 citations
TL;DR: A new configuration of patch antenna is introduced, which provides a dual-band operation and an array geometry designed by using the above structure is suggested, which can be suitable for satisfying the requirements of a typical dual-frequency SAR antenna.
Abstract: A new configuration of patch antenna is introduced, which provides a dual-band operation. This structure consists of an S-band cross patch with four square patches printed in the empty spaces among the arms of the cross. These patches provide a subarray working at X-band. This structure is simple to design and offers the advantage that it can be printed on a single-layer. An array geometry designed by using the above structure, is suggested. This can be suitable for satisfying the requirements of a typical dual-frequency SAR antenna.
42 citations
Patent•
31 May 1995TL;DR: An antenna for a base station in a mobile radio communication system with at least one base station and at least 1 mobile station is disclosed in this article, where the antenna comprises a microstrip antenna array with a matrix of microstrip patches.
Abstract: An antenna for a base station in a mobile radio communication system with at least one base station and at least one mobile station is disclosed. The antenna comprises a microstrip antenna array with a matrix of microstrip patches with at least two columns and two rows. In addition, a plurality of amplifiers is provided wherein each power amplifier is connected to a different column of microstrip patches. Finally, beamformers are connected to each power amplifier for determining a direction and shape of narrow antenna lobes generated by the columns of microstrip patches.
35 citations
TL;DR: In this paper, a new circularly polarized rectangular microstrip antenna using a proximity-coupled feed method is proposed, which allows easy connection between a microstrip line and an antenna element.
Abstract: A new circularly polarized rectangular microstrip antenna using a proximity-coupled feed method is proposed in this paper. This antenna is fed by a microstrip line offset from the center of a rectangular microstrip antenna. The proposed antenna has no 90-degree hybrid coupler for circular polarization and allows easy connection between a microstrip line and an antenna element. The measured results verify the circular polarization and show that good return loss and axial ratio characteristics have been obtained. >
34 citations
TL;DR: In this paper, a dual-band microstrip antenna is introduced, which consists of multiple layers with metallic strips placed at one of the dielectric interfaces under the radiating patch.
Abstract: A novel dual-band microstrip antenna is introduced. The entire structure is planar and can be easily mass-produced by using printed-circuit technology. The antenna consists of multiple layers with metallic strips placed at one of the dielectric interfaces under the radiating patch. The resonant frequencies can be selected over a wide frequency range, and the impedance matching at those two frequencies is relatively simple. The physically intuitive cavity model is used for the analysis. A relatively simple design scheme is included. >
29 citations
01 Jan 1995
TL;DR: In this paper, a review of antenna array techniques is presented, including the Synthesis of Shaped Patterns with Series-Fed Microstrip Patch Arrays, Coplanar Corporate Feed Effects in Micro Strip Patch Array Design, and a study of Microstrip Array Antennas with the feed network design.
Abstract: This chapter contains sections titled: Review of Microstrip Antenna Array Techniques The Synthesis of Shaped Patterns with Series-Fed Microstrip Patch Arrays Coplanar Corporate Feed Effects in Microstrip Patch Array Design A Study of Microstrip Array Antennas with the Feed Network Design Considerations for Low Sidelobe Microstrip Arrays A Parallel-Series-Fed Microstrip Array with High Efficiency and Low Cross-Polarization
TL;DR: This paper details the use of a circuit-based EM modelling technique combined with a harmonic balance simulator used to model the radiation from the microstrip bodies comprising an active antenna circuit.
Abstract: This paper details the use of a circuit-based EM modelling technique combined with a harmonic balance simulator used to model the radiation from the microstrip bodies comprising an active antenna circuit. The modelling approach adopted for the planar bodies in the circuit will be shown to allow the use of concurrent algorithms in order to reduce overall computational time.
18 Jun 1995
TL;DR: In this article, a dual-band microstrip array antenna is designed, fabricated, and tested, which consists of two aperture-coupled microstrip arrays sub-antennas stacked one over the other.
Abstract: A dual-band microstrip array antenna is designed, fabricated, and tested. The design consists of two aperture-coupled microstrip array sub-antennas stacked one over the other. Experiments have been conducted to validate the practicability of the dual-band antenna in terms of the radiation pattern and inter-frequency band interference.
TL;DR: In this paper, a 2/spl times/2 element planar microstrip-patch sub-array is described for the 35 GHz band, which can be used as a basis configuration for design of large, high-gain arrays.
Abstract: A classical configuration of a planar array of microstrip rectangular patches, fed by a corporate-feed arrangement, is widely used for many applications. There are several reports devoted to the design of such antennas. However, they are based on semi-empirical approaches, especially at mm-wave frequencies. A good choice of an array-feeding-network layout is a cornerstone problem for the antenna's design. The purpose of this report is to give a description of a 2/spl times/2 element planar microstrip-patch sub-array, which can be used as a basis configuration for design of large, high-gain arrays, for the 35 GHz band.
18 Jun 1995
TL;DR: The characteristics of an enhanced bandwidth low-profile integrated antenna, the radiation coupled dual L antenna, are presented, which radiates isotropically and offers a number of design options for impedance matching.
Abstract: This paper presents the characteristics of an enhanced bandwidth low-profile integrated antenna, the radiation coupled dual L antenna. The characteristics are determined by both measurements and computer simulations. This antenna is obtained by modifying the planar inverted F antenna (PIFA) to increase the bandwidth. The bandwidth is enhanced without increasing the antenna depth. The radiation coupled dual L antenna radiates isotropically and offers a number of design options for impedance matching. Compared with a PIFA of equal height, its bandwidth is higher by at least 50%. An insight as to which parameters have a dominant affect on the input impedance of this antenna is used to develop a methodology to design enhanced bandwidth dual L antennas. Special attention is paid to the input impedance characteristics, since both the PIFA and the dual L have very broad antenna patterns and the bandwidth defined by acceptable radiation patterns is usually quite larger than the impedance bandwidth.
04 Apr 1995
TL;DR: In this paper, a microstrip patch antenna employing a novel feed arrangement is presented, where energy is coupled to the radiating patches via a continuous slotline in the microstrip ground plane.
Abstract: A microstrip patch antenna employing a novel feed arrangement is presented. By using the slotline to microstrip coupling, energy is coupled to the radiating patches via a continuous slotline in the microstrip ground plane. This allows the patches and the feeding slotlines to be fabricated on a single substrate minimising device areas in MMICs. Using Hewlett Packard's high frequency structure simulator (HFSS) the electric and magnetic field distribution on a single patch design have been analysed. The results of measurements performed in an anechoic chamber are presented which show the radiation characteristics of a 10 GHz prototype antenna using the new feed mechanism. >
18 Jun 1995
TL;DR: It has been shown that the double-deck microstrip patch antenna can have a lower input VSWR and realize a flat gain within a desired bandwidth by adopting the combination method of the antenna's structure and matching network.
Abstract: A new approach for the design of broadband double-deck microstrip patch antenna is presented. It has been shown that the double-deck microstrip patch antenna can have a lower input VSWR and realize a flat gain within a desired bandwidth by adopting the combination method of the antenna's structure and matching network. The achieved input impedance bandwidth are 25% and 23% for a VSWR lower than 1.7 and 1.5 respectively.
18 Jun 1995
TL;DR: In this paper, a planar inverted F antenna (PIFA) was proposed as a built-in antenna for the Japanese Personal Handy Phone System (PHS) at 1.9 GHz band.
Abstract: In personal communication systems (PCS) and the Japanese Personal Handy Phone System (PHS), the size and the shape of the handset is of great importance with regards to the portability, the tractability, and the design. In these respects, a built-in antenna like the planar inverted F antenna (PIFA) on the handset is desirable. We propose a new built-in antenna system on a handset for the PCS and PHS at 1.9 GHz band. Previously, almost the same structure applied to a /spl lambda//4 monopole antenna system was successful in enhancing the horizontal plane gain and controlling the antenna pattern. The new structure is shown to be also applicable to the PIFA as a built-in antenna. The conclusions are confirmed by the experiments and the calculations using the method of moments.
TL;DR: In this paper, the authors proposed an efficient amelioration of the concept of large bandwidth aperture-coupled microstrip antennas by coupling a CPW line-fed slot to a microstrip antenna.
Abstract: The authors propose an efficient amelioration of the concept of large bandwidth aperture-coupled microstrip antennas by coupling a CPW line-fed slot to a microstrip antenna. The CPW fed aperture-coupled microstrip antenna investigated has a large bandwidth with high gain and low crosspolarisation levels, is compact with only one substrate, and may be easily connected to both passive and active components. A numerical model has been developed and the theoretical results are in good agreement with the experiments.
18 Jun 1995
TL;DR: In this article, the performance of a microstrip Yagi array is analyzed by using a full-wave analysis and a moment-method calculation, and the characteristics of the Yagi arrays are studied.
Abstract: It has been reported that the antenna bandwidth of a microstrip antenna can be significantly increased by adding parasitic patches. Recently, a new microstrip antenna structure with several parasitic patches called the microstrip Yagi array antenna has found applications in mobile satellite systems. One reason for such applications is that the antenna's mainbeam radiation can be tilted away from the broadside direction, due to strong coupling between the driven and parasitic patches. Because of this strong coupling, the performance of a microstrip Yagi array is very sensitive to various array parameters. A rigorous analysis is thus required to accurately determine the performance of a microstrip Yagi array. This problem is studied by using a full-wave analysis and a moment-method calculation. The characteristics of a microstrip Yagi array are studied.
18 Jun 1995
TL;DR: In this article, a new broadband and compact microstrip antenna design has been proposed, which gives good impedance bandwidth of the order of 10% and requires a smaller area compared to an ordinary corresponding circular patch antenna.
Abstract: A new broadband and compact microstrip antenna design has been proposed. This design gives good impedance bandwidth of the order of 10%. The new conformal antenna requires a smaller area compared to an ordinary corresponding circular patch antenna.
TL;DR: In this article, a theoretical development for the analysis of a microstrip antenna on a conical surface operating in the TM10 mode is described, based on using the cavity model with magnetic side walls for the calculation of the resonant frequency and input impedance.
Abstract: A theoretical development for the analysis of a microstrip antenna on a conical surface operating in the TM10 mode is described here. It consists of using the cavity model with magnetic side walls for the calculation of the resonant frequency and input impedance. The dyadic Green's-function formulation is used for the calculation of the radiated far fields. Particular antennas are examined and numerical results are shown for the TM10 mode.
18 Jun 1995
TL;DR: In this paper, a two-layer five-patch microstrip antenna using a coplanar technique, i.e. additional patch is etched on the same layer, is investigated and a simpler geometry with similar bandwidth is obtained.
Abstract: An offset tri-patch microstrip antenna of percentage bandwidth 48% was reported in Tong and Luk (1994). It is found that the complexity in geometry of the antenna can be modified. In the present paper, a two-layer five-patch microstrip antenna using a coplanar technique, i.e. additional patch is etched on the same layer, is investigated. A simpler geometry with similar bandwidth (44.5%) is obtained. The radiation patterns of the antenna are also presented.
TL;DR: In this article, the electromagnetic scattering from a spherical-circular microstrip antenna is analyzed using a full-wave analysis incorporating Galerkin's moment method, and the radar cross sections (RCSs) are calculated and compared with the corresponding results for the planar circular microstrip antennas.
Abstract: The electromagnetic scattering from a spherical-circular microstrip antenna is analyzed using a full-wave analysis incorporating Galerkin's moment method. The radar cross sections (RCSs) are calculated in this study and compared with the corresponding results for the planar circular microstrip antenna. Numerical results for various curvature radii and substrate thicknesses are presented and discussed. The effects of the substrate's uniaxial anisotropy on the scattering behavior are also investigated. © 1995 John Wiley & Sons, Inc.
04 Apr 1995
TL;DR: In this article, a theoretical analysis of conformal microstrip antenna arrays laid out on conical surfaces is presented, taking into account the phase shifts, and the results for single or multiple belt arrays are given.
Abstract: A theoretical analysis of conformal microstrip antenna arrays laid out on conical surfaces is presented. The results for single or multiple belt arrays, taking into account the phase shifts, are given. An experimental validation of the computer program has been achieved with a pyramidal realisation. We show the particular effects on the radiation pattern when changing phases are applied to the patches. >
18 Jun 1995
TL;DR: In this paper, a novel geometry of a spherical-circular microstrip antenna gap-coupled with an annular-ring parasitic patch is studied, and a rigorous Green's function formulation in the spectral domain and a Galerkin's moment method calculation are applied.
Abstract: Various characteristics of a single spherical microstrip antenna have been rigorously analyzed using a full-wave approach. The coupling problem between two spherical microstrip antennas, however, is not addressed. A novel geometry of a spherical-circular microstrip antenna gap-coupled with an annular-ring parasitic patch is studied. By choosing a gap spacing between the circular disk and the annular-ring patch to be about one substrate thickness or less, it is expected that the antenna bandwidth of the spherical-circular microstrip antenna can be increased. To study this problem, a rigorous Green's function formulation in the spectral domain and a Galerkin's moment method calculation are applied. The input impedance at the driven circular disk is formulated and calculated, and the results for the voltage standing wave ratio (VSWR) are presented. The antenna bandwidth determined by a VSWR /spl les/2.0, is then discussed.
TL;DR: In this paper, the design, fabrication, testing, and analysis of a tiny microstrip ring antenna is described, and a novel analytical technique is developed for the dimensions and operational properties of this antenna.
Abstract: The design, fabrication, testing, and analysis of a novel tiny microstrip ring antenna is described. A novel analytical technique is developed for the dimensions and operational properties of this antenna. Measured performance data of the ring antenna are presented and compared with calculated results. Very good agreement between theory and experiment was achieved. © 1995 John Wiley & Sons, Inc.
20 Feb 1995
TL;DR: In this article, a PIFA (planar inverted F antenna), two conducting bodies divided from a body, and a short plate connecting the two bodies was proposed to improve the horizontal plane peak gain and average gain.
Abstract: We propose a new built-in antenna system on a handset for PCS and PHS (Japanese digital cordless phone) at 19 GHz The new antenna system consists of a PIFA (planar inverted F antenna), two conducting bodies divided from a body, and a short plate connecting the two bodies The new antenna system improves the horizontal plane peak gain and average gain about 2 dB in free space, even at the very proximity to the hand and head The experiments and the calculations confirmed it
01 Jan 1995
TL;DR: In this paper, a broad band and compact microstrip antenna design has been proposed, which gives good impedance bandwidth of the order of 10% and requires only a lesser area conpured to reduce the power consumption.
Abstract: A new broad band and compact microstrip antenna design has been proposed. This design gives good impedance bandwidth of the order of 10%. The tiew antenna requires only a lesser area conpured to uti ordinury corre.ypotiding circiilur putcli unienriu.
18 Jun 1995
TL;DR: In this paper, the backscattering radar cross section (RCS) of a spherical-circular microstrip antenna is calculated using the Galerkin's moment method, and the obtained RCS results are compared with the results of a corresponding planar circular micro-strip antenna.
Abstract: Electromagnetic scattering by planar microstrip antennas has received much attention. However, the related scattering studies for conformal microstrip antennas are very scant. In this article, the scattering from a spherical-circular microstrip antenna is investigated. This study is performed by using a rigorous Green's-function formulation in the spectral domain, and the numerical results of the backscattering radar cross section (RCS) of the microstrip antenna are calculated by using Galerkin's moment method. The obtained RCS results of the spherical-circular microstrip antenna are also compared with the results of a corresponding planar circular microstrip antenna to analyze the curvature effect on the scattering from a microstrip antenna.