Showing papers on "Metamaterial antenna published in 1981"
TL;DR: In this paper, a technique for controlling the operating frequency and polarization of microstrip antennas is proposed, which is achieved by placing shorting posts at appropriate locations within the antenna's boundaries.
Abstract: A technique is investigated for controlling the operating frequency and polarization of microstrip antennas. The control is achieved by placing shorting posts at appropriate locations within the antenna's boundaries. By changing the number and locations of the posts, the operating frequency can be tuned over a 1.5-to-1 range, and the polarization can be changed from horizontal to vertical, right-hand circular, or left-hand circular. All of these changes are obtained without significantly altering the input impedance or radiation patterns of the antenna and without increasing the complexity of the external microwave feed network. The frequency and polarization can be electronically controlled by using microwave switching diodes for the shorting posts. Antennas that have two feeds and operate simultaneously in two orthogonal polarizations have been constructed with the capability to switch between linear and circular polarization. Also, a thin frequency-scanned array has been built with the frequency-agile microstrip elements.
311 citations
TL;DR: Past and present technological developments in microstrip antenna arrays are summarized and emphasis is on exploring the potential of such arrays for satisfying the requirements of advanced military and commercial applications.
Abstract: Past and present technological developments in microstrip antenna arrays are summarized. Emphasis is on exploring the potential of such arrays for satisfying the requirements of advanced military and commercial applications.
276 citations
TL;DR: In this paper, an antenna consisting of an interconnected wire grid formed by etching metallic lines on a dielectric sheet backed by a metallic ground plane is described, and the theory of operation, analytical model, and experimental findings for this approach to a printed array are described.
Abstract: A description is given of an antenna consisting of an interconnected wire grid formed by etching metallic lines on a dielectric sheet backed by a metallic ground plane. The theory of operation, analytical model, and experimental findings for this approach to a printed array are described. The device is low cost, light weight, and has sufficient bandwidth to be of use in a variety of applications. An analytical model is developed which establishes transmission line equivalent circuits for the wire grid elements. Current distributions determined from the model are shown to predict accurately the measured pattern performance of a typical implementation. The bandwidth as established by various pattern parameters is quantitatively assessed. Particular emphasis is given to methods of amplitude control through control of line impedances. A particular design implementation is presented for a five-wavelength circular array with independent quadrant control. Measured results from this configuration are compared to theory.
120 citations
TL;DR: In this paper, a new class of printed circuit radiator consisting of a microstrip dipole electromagnetically coupled to the microstrip feed line is described, and several configurations which differ in bandwidth, efficiency, and construction simplicity are presented.
Abstract: A new class of printed circuit radiator consisting of a microstrip dipole electromagnetically coupled to a microstrip feed line is described. Several configurations which differ in bandwidth, efficiency, and construction simplicity are presented. A geometry which has been found to be optimum for many applications is noted. Radiation characteristics of both isolated elements and arrays of elements are examined. Experimental and theoretical results are presented.
118 citations
TL;DR: In this paper, the feasibility of low-cost conformal printed circuit board antenna arrays at millimeter wave frequencies is presented, and the results obtained with actual experimental hardware are described.
Abstract: Proof of the feasibility of low-cost conformal printed circuit board antenna arrays at millimeter wave frequencies is presented It has become apparent that present day trends in microwave systems are indicating extensive design efforts in the millimeter wave region Many proposed systems will be seriously hindered by a lack of readily available inexpensive components Microstrip conformal antennas have distinct advantages in cost, variety of field pattern, and reproducibility for microwave system design It is felt that similar advantages could be realized at millimeter wave frequencies The results obtained with actual experimental hardware are described Discussed are 4 \times 4 element arrays operating in the 35- and 60-GHz regions and a 32 \times 32 element array operating near 38 GHz
50 citations
TL;DR: In this paper, the authors describe the performance of an array of broadband elements fed by a microstrip corporate feed network and show that bandwidths up to 15 percent can be obtained at the expense of an increase in the antenna height (to about 0.1 wavelength).
Abstract: Foam-supported highly efficient microstrip antennas are described. Theoretical and experimental results show that bandwidths up to 15 percent can be obtained at the expense of an increase in the antenna height (to about 0.1 wavelength). The performance of an array of broadband elements fed by a microstrip corporate feed network is also described.
20 citations
26 Jan 1981
TL;DR: A microstrip backfire antenna as discussed by the authors consists of a microstrip element in a cavity between a total reflector and a partial reflector, characterized by multiple reflections of electromagnetic waves between the two reflectors and by energy being radiated normal to and through the partial reflectors.
Abstract: A microstrip backfire antenna which combines the microstrip type antenna ment with a backfire cavity to provide more than three times the gain over a single microstrip element and thereby be capable of replacing four or more elements of a conventional microstrip array. The microstrip backfire antenna consists of a microstrip element in a cavity between a total reflector and a partial reflector and is characterized by multiple reflections of electromagnetic waves between the two reflectors and by energy being radiated normal to and through the partial reflector.
17 citations
16 Jun 1981
2 citations
16 Jun 1981
1 citations
16 Jun 1981
01 Jan 1981
TL;DR: In this article, recent advances in the mathematical analysis of microstrip antennas are outlined and the extent to which they model the precise physical action is particularly discussed together with likely sources of error.
Abstract: The analyses of microstrip antenna element configurations discussed in earlier chapters were based on some degree of approximation concerning the current and field distributions. The results obtained show reasonable agreement with practical results in some cases, but various adjustments have to be made to the parameters used in the calculations to improve agreement. Examples of this are the use of effective widths of open circuit transmission lines rather than the physical width to calculate the radiation conductance and the allowances for fringe fields in calculating the resonant frequency of patch antennas. In this chapter, recent advances in the mathematical analysis of microstrip antennas are outlined and the extent to which they model the precise physical action is particularly discussed together with likely sources of error.
16 Jun 1981
TL;DR: In this paper, a class of variable power division circuits which can be used to implement a phase invariant adjustable power divider is discussed. And the associated problem of system analysis is discussed, particularly the inclusion of the antenna element coupling.
Abstract: Relatively few types of variable power division circuits have been used in medium wave directional antenna feed systems, most of which suffer phase variation as the power division is adjusted. This paper discusses a class of circuits which can be used to implement a phase invariant adjustable power divider. Also discussed are variable phase shifters which have limited effect on power distribution. These features can simplify the original tuning and possible periodic maintenance. A computer analysis of the probable performance of such devices is presented. The associated problem of system analysis is discussed, particularly the inclusion of the effects of the antenna element coupling. To this end a lumped passive element model for a generalized linear reciprocal N port is presented.