Showing papers on "Folded inverted conformal antenna published in 1990"

Broad-band gap coupled microstrip antenna

Abstract: A microstrip antenna with large bandwidth is developed using a parasitic technique. Compared to the available wideband antennas, the proposed antenna structure is very compact and gives a less distorted radiation pattern with frequency. An impedance bandwidth eight times that of a conventional patch antenna of the same size is achieved. The concept of coupled microstrip line model is extended for theoretical interpretation of the impedance loci. The experimental procedure and results are described, and a theoretical analysis is presented. >

Microstrip line antenna with crank-shaped elements and resonant waveguide elements

Abstract: A microstrip line antenna generally used for receiving an electric wave from an artificial satellite, which comprises a plane dielectric substrate and a plurality of crank-shaped microstrip lines arranged on the substrate. The improvement comprises a number of half wavelength waveguide elements arranged on a plane lying parallel to the substrate in front of the microstrip lines at a predetermined distance therefrom for improving the signal-to-noise ratio of the antenna and reducing the number of antenna elements.

Planar antenna with active circuit block

Abstract: A planar antenna has an active circuit block, the whole or part of which is internally mounted to a planar antenna body so that connecting terminal of the block will be connected to a feeding point on power supply plate of the antenna body. Dimensional minimization of the entire antenna can be thereby attained and noise figure of the active circuit can be simultaneously reduced.

Equivalence of radiation properties of square and circular microstrip patch antennas

Abstract: The radiation properties of a circular microstrip antenna are compared with those of an equivalent square microstrip antenna. On the basis of this comparison, a simple method of computing the far field of a circular microstrip antenna is suggested. >

Analysis of planar inverted F antenna using spatial network method

Abstract: It is shown that the input impedance of the PIFA (planar inverted F antenna) can be calculated using the SNM (spatial network method). The transition characteristics of the resonant frequency and the bandwidth of the PIFA are described for various values of the shape ratio and the shorted width of the planar element. The calculated results are in close agreement with measured results when the analysis area is set large enough. It has been numerically clarified that the PIFA's resonant frequency decreases with decrease of the shorted element width for various planar element size ratios L/sub 1//L/sub 2/, and the relative bandwidth decreases when the shorted element width, the antenna height, or the antenna size ratio L/sub 1//L/sub 2/ decreases. >

Elliptical microstrip antenna on ferrite substrate

Abstract: A formula for the resonant frequency of an elliptical microstrip antenna on ferrite substrate is developed. Using an integrating averaging procedure the formula is modified to give the exact formula for the resonant frequency of the ferrite based microstrip antenna. The experimental result reveals the accuracy of the formula.

On the resonant frequency of the normal mode helical antenna excited by a loop

Abstract: The resonant performance of the electrically small helical antenna excited by a loop is investigated by the moment method, using second order B-spline functions as basis functions. Although the antennas studied are electrically very small, the program provides convergent results which agree well with those of the experiment. It is shown that the resonant frequency of the antenna is closely related to the helix parameters. When the wire length is held constant, the resonant frequency increases with the pitch and decreases when the radius of the helix is increased. With a fixed helix diameter, a critical turn spacing exists which determines whether the resonant length is greater or less than one half wavelength. By adjusting the turn spacing of the helix, a specific resonant frequency can be obtained.

Current distributions and far field radiated by an arbitrary shape large bandwidth microstrip antenna

Abstract: It is well known that the bandwidth of a microstrip antenna can be increased by overlaying a parasitic element or director. A radioelectric model was presented [l] to explain this property in the case of a rectangular patch antenna. The purpose of this communication is a generalization of the analysis for an arbitrary shape symmetrical patch antenna coupled with a director. A quasi TEM two coupled transmission lines model is used to express the conduction and polarization current distributions and then the radiation patterns of an arbitrary-shape symmetrical patch coupled with a director and acting in a large bandwidth. In the particular case of the circular shape, theoretical results are in good agreement with experiments. The whole paper summarizes a recent thesis [2].

An optimized impedance-matching technique for increasing the bandwidth of microstrip antenna

Abstract: The usefulness of broadband impedance matching to increase the bandwidth of a microstrip patch antenna is illustrated using three different antenna configurations. Measured data for a patch antenna was incorporated into commercial CAD software to design a matching network. Design limitations are also discussed. Practical design examples and experimental results are given which clearly demonstrate the validity of this technique.