Showing papers on "Folded inverted conformal antenna published in 1989"
TL;DR: In this article, an original analysis of the aperture coupling of a microstrip antenna is presented, based on the cavity model, and results are compared with the moment method and measurement.
Abstract: The letter presents an original analysis of aperture coupling of a microstrip antenna. The theory is based on the cavity model, and results are compared with the moment method and measurement
85 citations
TL;DR: In this paper, a dual-frequency antenna consisting of a square microstrip patch with a rectangular notch is experimentally investigated and the resonant frequencies and return loss are shown as a function of the rectangular notch depth.
Abstract: A dual-frequency antenna consisting of a square microstrip patch with a rectangular notch is experimentally investigated. The resonant frequencies and return loss are shown as a function of the rectangular notch depth. The radiation patterns show that the polarisation planes at the first and second resonant frequencies are perpendicular to each other.
72 citations
Patent•
29 Dec 1989TL;DR: In this paper, a folded broadband antenna is integrated into a leading edge radome, eliminating the forward antenna cavity, and thereby eliminating the internal wall reflections that cause radiation pattern distortion.
Abstract: A folded broadband antenna provides a symmetrical radiation pattern comparable to corresponding planar antennas (such as a planar spiral). The folded antenna can be integrated into a leading edge radome, eliminating the forward antenna cavity, and thereby, eliminating the internal wall reflections that cause radiation pattern distortion. A broadband antenna (61/62), such as an archimedean spiral, is folded at an apex area (64) that includes a fold-slot (66). The fold-slot enhances flexure, and allows a center-feed balun shielding tube (84) to extend into close proximity to the antenna aperture (61) for increased balun shielding.
57 citations
TL;DR: In this paper, an appropriately corrected formula for the resonant frequencies of microstrip antenna elements is obtained that is based on the evaluation of the average value of the effective dielectric constant.
Abstract: An appropriately corrected formula for the resonant frequencies of microstrip antenna elements is obtained that is based on the evaluation of the average value of the effective dielectric constant. The author describes the integration averaging technique and presents two examples of its use in more accurately calculating the resonant frequencies of the first five modes of an equilateral triangular microstrip antenna. >
51 citations
TL;DR: In this paper, a rigorous analysis of the features of the modes of an ideal-gap open-ring (closed ring with a cross cut) printed microstrip antenna is presented, where general expressions for its radiation field are derived by using the cavity model, trigonometric identities, and the properties of cylindrical functions.
Abstract: A rigorous analysis of the features of the modes of an ideal-gap open-ring (closed ring with a cross cut) printed microstrip antenna is presented. General expressions for its radiation field are derived by using the cavity model, trigonometric identities, and the properties of the cylindrical functions. The solution and the computed results for the radiation patterns and the field distributions for the even and odd modes are presented. The solutions for the even modes are the same as those for the closed-ring printed microstrip antenna. The results for the radiation patterns and other antenna characteristics for the odd modes indicate the superiority in the radiation properties of the ideal-gap open ring when excited in the TM/sub 12/ mode over those of a closed ring. >
21 citations
26 Jun 1989
TL;DR: In this paper, a spherical conformal array antenna that has 64 elements with a digital beam-forming network was tested and low sidelobe pattern synthesis of a conformal antenna using the network was demonstrated.
Abstract: A spherical conformal array antenna that has 64 elements with a digital beam-forming network has been tested. Low sidelobe pattern synthesis of a conformal array antenna using the network was demonstrated. Multiple beam forming with maximum gain was also considered. >
9 citations
01 Oct 1989
TL;DR: In this article, a novel Blade Antenna using microstrip patch elements is described, capable of producing a horizontally polarised beam with omnidirectional coverage in the horizontal plane when mounted vertically on an aircraft.
Abstract: A novel Blade Antenna using microstrip patch elements is described. This antenna is capable of producing a horizontally polarised beam with omnidirectional coverage in the horizontal plane when mounted vertically on an aircraft. A scaled experimental model designed to operate at 2.8GHz with 4% bandwidth capability (VSWR 2 to 1) is described. This antenna is lightweight and can easily be fabricated using printed circuit techniques.
4 citations
01 Oct 1989
TL;DR: In this article, an integrated multi-channel, multi-frequency microstrip antenna array with a given limited aperture is described. But the performance of the array is limited by the number of microstrip patches that can operate at different frequencies.
Abstract: This paper describes an integrated, multi-channel, multi-frequency microstrip antenna array confined to a given limited aperture. Integration of several channels has become important in the development of wide scan angle phased-array antennas that operate without the appearance of grating lobes. The integrated array presented here is built from special multi-channel microstrip elements. Each element of the array consists of microstrip patches operating at different frequencies which are integrated into one microstrip element. This unique technique reduces the weight and dimensions of the multi-channel array, compared to that of separated arrays with the same performance.
2 citations
01 Jan 1989
1 citations
TL;DR: In this article, a broadband two-port feeding technique based on the principle of reactance compensation is suggested. But it is not shown that this technique enables the VSWR bandwidth to be broadened to 2-3 or more times that of a conventional design for both linear and circular polarization operation.
Abstract: In order to broaden the bandwidth of a microstrip patch antenna, a broadband two-port feeding technique based on the principle of reactance compensation is suggested. The principle and some design guidelines are presented; the calculating model of a practical configuration as well as its parameter optimization is demonstrated, followed by several kinds of test models with their experimental results. It is shown that this technique enables the VSWR bandwidth to be broadened to 2–3 or more times that of a conventional design for both linear and circular polarization operation.
1 citations
01 Jan 1989
TL;DR: In this paper, the authors describe the design, construction and testing of a prototype monopulse tracking antenna that is realized as a thin microstrip/triplate structure conformal to the surface of a cone.
Abstract: This chapter describes the design, construction and testing of a prototype monopulse tracking antenna that is realised as a thin microstrip/triplate structure conformal to the surface of a cone. The main application of such an antenna configuration is to provide guided-weapon seeker antennas for high speed (> Mach 2-5) missiles and shells where the pointed (high fineness) front ends make conventional antenna (reflector or flat plate) plus radome designs impracticable owing to severe radome aberration effects. The latter is due to the high angles of incidence with which the antenna must necessarily illuminate the radome, as well as radome-tip scattering and blockage. Other applications exist where conical, or near conical, geometries are found there are obviously many possible aircraft sites, and the antenna configuration described should find applications here. In the context of guided weapons, tracking antennas are required for both narrow and broadband applications: narrow band for active and semi-active seekers and broadband for passive anti-radiation seekers. The design as discuss ed is narrow band, having a bandwidth of ~ 10% centered at 10 GHz; techniques to extend the bandwidth to over 50% are discussed at the end of the chapter. The antenna as described consists of microstrip radiators on the conical surface with an adjacent (underneath) triplate feed network. Emphasis is given in the chapter to the practical engineering problems that have been encountered and solved during the design and development programme.
26 Jun 1989
TL;DR: In this article, a closed-form expression for the total stored energy of an open-ring structure is derived and used to determine the corresponding figure of merit in terms of the antenna gain-bandwidth product.
Abstract: A closed-form expression for the total stored energy of an open-ring structure is derived and used to determine the corresponding figure of merit in terms of the antenna gain-bandwidth product. The gain is proportional to the input impedance at resonance R/sub 0/ and the bandwidth is inversely proportional to the total quality factor Q/sub T/ of the antenna. The results for the antenna R/sub 0//Q/sub T/ figure are shown for the TM/sub 11/ mode and the TM/sub 12/ modes. They indicate that different structures can have the same R/sub 0//Q/sub T/ figure. >