Showing papers on "Folded inverted conformal antenna published in 1998"
TL;DR: In this paper, a variation of the aperture-coupled stacked patch microstrip antenna is presented, which greatly enhances its bandwidth, and the impedance behavior of this antenna is compared with that of other wideband radiators.
Abstract: A variation of the aperture-coupled stacked patch microstrip antenna is presented, which greatly enhances its bandwidth. Bandwidths of up to one octave have been achieved. The impedance behavior of this antenna is compared with that of other wide-band microstrip radiators. Matching techniques for the antenna are presented and their relative merits discussed. The effects of varying several key physical parameters of the antenna are investigated, lending some insight into its wide-band operation. Variations on the design such as incorporation of additional patches are also discussed.
515 citations
TL;DR: In this paper, the characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated and a foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate.
Abstract: The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband.
455 citations
TL;DR: In this paper, a folded reflectarray antenna is presented, which combines a twist and focusing reflector concept in a single printed structure, together with a printed grid, a low profile and high gain antenna results.
Abstract: A novel folded reflectarray antenna is presented. This antenna combines a twist and focusing reflector concept in a single printed structure. Together with a printed grid, a low profile and high gain antenna results. A test antenna in the 20 GHz range was designed, fabricated and tested.
126 citations
TL;DR: In this paper, a single-feed square microstrip antenna with truncated corners was proposed for single-input single-out (SISO) single-output (SIMO) applications.
Abstract: A novel circular polarisation (CP) design of a single-feed square ring microstrip antenna with truncated corners is described. Experimental results show that the proposed design has a reduced antenna size as compared to the conventional circularly-polarised square microstrip antenna with truncated corners at a given operating frequency. Also, the required size of the truncated corners for CP operation is larger for the present design than for the conventional design using a square microstrip patch, which suggests that the fabrication tolerance is relaxed for the present design. Typical results are presented and analysed.
118 citations
TL;DR: The vertical folded loop antenna, modeled as wire and printed radiating element mounted on a conducting box, simulating a cellular telephone with and without dielectric coating, is analyzed and meets the design requirements for existing and future mobile communication systems.
Abstract: The vertical folded loop antenna, modeled as wire and printed radiating element mounted on a conducting box, simulating a cellular telephone with and without dielectric coating, is analyzed. The finite-difference time-domain (FDTD) method is used to calculate radiation patterns and input impedance. The results are compared with measurements and with NEC data. Very good agreement is obtained in all cases. Parasitic loading is used to enhance the bandwidth of the printed element. The antenna meets the design requirements for existing and future mobile communication systems.
81 citations
TL;DR: In this article, a square slot at the center of a rectangular microstrip patch is used to achieve both compactness and dual-frequency operation in order to reduce the required antenna size.
Abstract: By cutting a square slot at the centre of a rectangular microstrip patch, both compactness and dual-frequency operation can be achieved. Several designs have been implemented. From the experimental results obtained, the required antenna size using the proposed design method can be reduced by /spl sim/17% compared to that of the conventional design method using a simple patch without the slot. Typical experimental results are presented and discussed.
77 citations
TL;DR: In this paper, a modified planar inverted F antenna (PIFA) is proposed to reduce the antenna length by meandering the radiating patch, while the enhanced bandwidth with low antenna height is obtained using a chip-resistor load in place of the shorting post.
Abstract: The design of a modified planar inverted F antenna (PIFA) which is more compact (antenna length
75 citations
07 Jun 1998
TL;DR: In this article, an aperture-coupled micromachined microstrip antenna operating at 94 GHz was proposed, which is an efficient solution to the vertical integration of antenna arrays at millimeter-wave frequencies.
Abstract: In this paper, we present an aperture-coupled micromachined microstrip antenna operating at 94 GHz. The design consists of two stacked silicon substrates: (1) the top substrate, which carries the microstrip antenna, is micromachined to improve the radiation performance of the antenna, and (2) the bottom substrate, which carries the microstrip feed line and the coupling slot. The measured return loss is -17 dB at 91 GHz for a 10-dB bandwidth of 11%. The radiation patterns show a measured front-to-back ratio of -10 dB at 91 GHz. The micromachined microstrip antenna is an efficient solution to the vertical integration of antenna arrays at millimeter-wave frequencies.
72 citations
TL;DR: In this article, a folded rectangular patch antenna was designed and measured, and compared with a conventional patch antenna with the same surface area, the resonant frequency was reduced by 37% and the cross-polarisation level was /spl sim/-20 dB.
Abstract: A novel folded rectangular patch antenna is designed and measured. Compared with a conventional patch antenna with the same surface area, the resonant frequency is reduced by 37%. The cross-polarisation level is /spl sim/-20 dB.
69 citations
TL;DR: By embedding a group of four bent slots in a corner-truncated square microstrip patch, a single-feed compact circularly polarised microstrip antenna can easily be obtained.
Abstract: By embedding a group of four bent slots in a corner-truncated square microstrip patch, a single-feed compact circularly polarised microstrip antenna can easily be obtained. Results show that for a given circular polarisation (CP) operation, the proposed antenna can have an antenna size reduction of more than 50% as compared to the conventional CP design using a corner-truncated square patch without the slots. Moreover, the 50/spl Omega/ feed position and truncated-corner size for achieving CP operation are found to be nearly independent of the bent slots introduced in the patch, which makes the proposed antenna easy to implement.
66 citations
TL;DR: In this article, a compact circular-polarization (CP) operation of a circular microstrip antenna, with a cross-slot in the patch center and a pair of peripheral cuts at opposite sides of the patch boundary, is proposed and experimentally studied.
Abstract: Novel compact circular-polarisation (CP) operation of a circular microstrip antenna, with a cross-slot in the patch centre and a pair of peripheral cuts at opposite sides of the patch boundary, is proposed and experimentally studied. For operation at a fixed frequency, the proposed antenna using a single probe feed, can have an antenna size reduction of /spl sim/20% as compared to regular size CP operation of a circular microstrip antenna. Details of the experimental results are presented and analysed.
21 Jun 1998
TL;DR: In this paper, the authors presented a method to simplify the calculations of cavity model analysis on a multi-layer microstrip antenna, which completely eliminated the problem of mode matching between layers and thus reduced the amount of calculation and computing time.
Abstract: This paper presents a method to simplify the calculations of cavity model analysis on a multi-layer microstrip antenna. The main feature of this method is the simplification of a multi-layer antenna structure into a single homogeneous layer antenna. This in effect completely eliminate the problem of mode matching between layers and thus reduces the amount of calculation and computing time. Theoretical results obtained using this method were compared with the experimental results and were round to give an error of less than 4%.
TL;DR: In this paper, a novel, compact, dual-frequency design for cutting a pair of bent slots in the center of a rectangular patch is demonstrated, which provides an antenna-size reduction as high as 32%, compared to that of using a simple patch without the slots.
Abstract: A novel, compact, dual-frequency design for cutting a pair of bent slots in the centre of a rectangular patch is demonstrated. For fixed dual-frequency operation, the proposed design provides an antenna-size reduction as high as 32%, compared to that of using a simple patch without the slots. Experimental results of the proposed design, with various sizes of the bent slots, are presented and analysed.
TL;DR: In this article, a novel broadband design for a circular microstrip antenna with reactive loading integrated within the circular patch is proposed and studied, where the reactive loading is provided by a microstrip structure of cascaded microstrip-line sections embedded inside a slot cut.
Abstract: A novel broadband design for a circular microstrip antenna with reactive loading integrated within the circular patch is proposed and studied. The reactive loading is provided by a microstrip structure of cascaded microstrip-line sections embedded inside a slot cut in the circular patch. The proposed broadband design has been implemented, and the experimental study shows that an antenna bandwidth /spl sim/3.2 times that of a conventional circular microstrip antenna can be obtained. Details of the proposed design are described, and experimental results of the antenna performance are presented and discussed.
Abstract: A micromachined rectangular cavity-backed microstrip patch antenna has been developed on high resistivity silicon wafers. This novel patch antenna has a much reduced effective dielectric constant and wide bandwidth.
Patent•
31 Mar 1998TL;DR: In this article, a cavity-backed microstrip dipole antenna array is provided with a microstrip feeder network and a plurality of dipoles which are etched and formed on a single printed circuit board (PCB).
Abstract: A cavity-backed microstrip dipole antenna array is provided with a microstrip feeder network and a plurality of dipoles which are etched and formed on a single printed circuit board (PCB). Therefore, the structure is simple and inexpensive. Moreover, the antenna array can operate over a wider frequency bandwidth, and the thickness can be reduced to 0.1 of the wavelength of the transmitted/received signal.
TL;DR: In this article, a probe-fed rectangular microstrip antenna with a pair of toothbrush-shaped slots embedded close to the nonradiating edges of the patch is presented, which is achieved by the excitation of two adjacent resonant frequencies of the TM10 and TMδ0 modes (1 < δ < 2).
Abstract: A novel broadband design of a probe-fed rectangular microstrip antenna with a pair of toothbrush-shaped slots embedded close to the nonradiating edges of the patch is presented. The proposed broadband design is achieved by the excitation of two adjacent resonant frequencies of the TM10 and TMδ0 modes (1 < δ < 2), to obtain a wide operating bandwidth. An antenna bandwidth as large as ~2.6 times that of a conventional rectangular microstrip antenna has also been obtained. Details of the proposed design and experimental results are presented.
TL;DR: In this article, a dual-frequency operation of a single-feed equilateral-triangular microstrip antenna with a pair of spur lines is demonstrated, and the two operating frequencies are of the same polarisation planes.
Abstract: Novel dual-frequency operation of a single-feed equilateral-triangular microstrip antenna with a pair of spur lines is demonstrated. The two operating frequencies are of the same polarisation planes and, by varying the spur-line length, the frequency ratio of the two operating frequencies is tunable in the range of ~ 1.2 - 2.1. Details of the antenna design are described, and experimental results are presented and discussed.
Patent•
30 Sep 1998TL;DR: In this article, an internal antenna arrangement for radio communications handsets was proposed to enable further miniaturization and combine antenna volume with the acoustic enhancing volume, where the antenna size and shape represents a constraint on handset miniaturisation if good antenna efficiency and bandwidth characteristics are to be maintained.
Abstract: This invention relates to internal antenna arrangements for radio communications handsets. Internal antenna size and shape represents a constraint on handset miniaturisation if good antenna efficiency and bandwidth characteristics are to be maintained. The use of acoustic enhancing volumes of free space about a handset's speaker unit also constrains further miniaturisation. The present invention provides an internal antenna arrangement which facilities further miniaturisation and which combines antenna volume with the acoustic enhancing volume.
TL;DR: By embedding a pair of properlybent narrow slots in an equilateral-triangular microstrip patch, broadband operation of microstrip antennas with an inset microstrip-line feed can be achieved as mentioned in this paper.
Abstract: By embedding a pair of properly-bent narrow slots in an equilateral-triangular microstrip patch, broadband operation of microstrip antennas with an inset microstrip-line feed can be achieved. With the proposed antenna design, the impedance bandwidth can be as large as /spl sim/3.0 times that of a corresponding simple triangular microstrip antenna. Some simple design rules for the proposed antenna have also been determined experimentally. The design rules and experimental results are presented and discussed.
TL;DR: In this article, a design using an inclined-slot-coupling feed for dual-frequency operation of a rectangular microstrip antenna with a cross-slot is described. And the frequency ratio of the two frequencies is very slightly affected by the cross slot length.
Abstract: A design using an inclined-slot-coupling feed for dual-frequency operation of a rectangular microstrip antenna with a cross-slot is described. Results show that, for a given dual-frequency operation, a reduction in antenna size of /spl sim/40% can be achieved by using this design. Also, the frequency ratio of the two frequencies is very slightly affected by the cross-slot length, and mainly determined by the aspect ratio of the patch, making the design simpler and easier to implement.
21 Jun 1998
TL;DR: In this paper, a miniature PIFA antenna consisting of multilayers of very high permittivity materials is presented. And the achieved antenna gain is 7 dBi and the bandwidth is 5.75.
Abstract: Bandwidth enhancement on a miniature PIFA antenna is demonstrated in this paper. The miniature PIFA antenna consists of multilayers of very high permittivity materials (/spl epsi//sub r/>35). A 75% reduction in size has been accomplished as compared to that of the conventional PIPA. The achieved antenna gain is 7 dBi and the bandwidth is 5.75.
21 Jun 1998
TL;DR: In this paper, a wideband single-layer patch antenna is presented, where the patch is suspended over the groundplane and supported by a nonconductive pin, fed by a three-dimensional transition connecting the patch to a perpendicular connector.
Abstract: The typical single layer patch printed on a dielectric substrate is a narrow band element. This well-known fact is mainly due to the limitations imposed by the dielectric substrate. From efficiency and cost considerations, in most of the cases, the substrate cannot be too thick. In order to increase the microstrip element bandwidth, additional resonators, in different configurations and combinations, can be used: parasitic elements, slots, etc. In this paper, a wide-band single-layer patch antenna is presented. The patch is suspended over the ground-plane and supported by a non-conductive pin. It is fed by a three-dimensional transition connecting the patch to a perpendicular connector. The typical bandwidth of this element (in terms of VSWR) is 90%. When built on a large ground-plane, the front-to-back of this element is better than 25 dB across the band.
24 May 1998
TL;DR: In this article, a novel design for a microstrip antenna with a large tuning range is presented, which consists of a rectangular patch antenna divided into two sections and connected using varactor diodes (or capacitors).
Abstract: A novel design for a microstrip antenna with a large tuning range is presented The layout of this antenna consists of a rectangular patch antenna divided into two sections and connected using varactor diodes (or capacitors) A sample microstrip antenna using the new design is fabricated and tested The experimental results of the resonant frequency is similar to the theoretical values, and the radiation pattern is also similar to that of a simple rectangular patch antenna
TL;DR: In this article, an actuator is developed, tested and employed on an actual microstrip patch antenna and its parasitic element, which is comprised of a stack of RAINBOW actuators.
Abstract: The major weakness of a microstrip patch antenna is its narrow bandwidth characteristic. One method that has been investigated to increase bandwidth is the addition of a parasitic element to the microstrip patch antenna. In an active microstrip patch antenna, variable bandwidth can be achieved by varying the spacing between the antenna and the parasitic element, which is fixed to a dielectric plate. In this study an actuator is developed, tested and employed on an actual microstrip patch antenna and its parasite. Since a relatively large displacement (1 cm) is needed, the actuator is comprised of a stack of RAINBOW actuators. This study takes advantage of the fact that, for antennas operating at higher frequencies, smaller absolute displacements will result in significant percentage changes in antenna bandwidth. The use of the parasite and the active system accounted for up to a factor of five increase in antenna bandwidth. Various control techniques were employed to counteract the effects of hysteresis and creep on the actuator. Because the use of metal components can degrade antenna performance, emphasis was placed on synergy in the design process.
TL;DR: An artificial neural network architecture is developed for design of circular microstrip antenna that takes the thickness of the substrate, dielectric constant and the resonant frequency in the dominant TM11 mode as its input and gives the correspondig radius of the circular patch.
Abstract: An artificial neural network architecture is developed for design of circular microstrip antenna. The network takes the thickness of the substrate, dielectric constant and the resonant frequency in the dominant TM11 mode as its input and gives the correspondig radius of the circular patch. A fast learning algorithm has been used for training.
TL;DR: In this paper, a planar dual-band internal antenna for handsets which operates in the /spl sim/0.9 and 1.8 GHz bands is proposed, which has almost the same size as a conventional internal antenna operating in the 0.9 GHz band.
Abstract: Cellular telephone handsets are now being designed to have dual-mode capabilities. In particular, GSM and DCS1800 modes are used in Europe. And PCS and AMPS modes are used in the USA. A novel planar dualband internal antenna for handsets which operates in the /spl sim/0.9 and 1.8 GHz bands is proposed. The dualband antenna has almost the same size as a conventional internal antenna operating in the 0.9 GHz band. Good dual-band operation was obtained for frequency ratios in the range 1.3-2.7.