초록 ▼

A generally planar antenna for generating circularly polarized electromagnetic signals, particularly useful at microwave frequencies. Each antenna element comprises a single excitation aperture (7) cut in a planar conductive ground plane (9). Spaced apart from the ground plane (9) by means of a diel

A generally planar antenna for generating circularly polarized electromagnetic signals, particularly useful at microwave frequencies. Each antenna element comprises a single excitation aperture (7) cut in a planar conductive ground plane (9). Spaced apart from the ground plane (9) by means of a dielectric layer (11) and covering the excitation aperture (7) is a planar conductive radiating patch (5) having slightly different dimensions along each of two orthogonal axes. The radiating patch (5) may have the shape of a near square or an ellipse. Exciting the aperture (7) with linearly polarized electromagnetic energy causes the radiating patch (5) to generate a circularly polarized electromagnetic signal consisting of two orthogonal components that have substantially the same amplitude and are 90°offset in phase from each other. Several antenna elements can be combined to form a large aperture array. Energy may be applied to the excitation aperture (7) by means of a waveguide (3) feed, microstrip line (15), or stripline (15).

대표청구항 ▼

An antenna element for generating circularly polarized electromagnetic signals, comprising: a single elongated excitation aperture cut in a planar conductive ground plane; in spaced parallel relation to the ground plane and completely covering the excitation aperture when viewed from a direction ort

An antenna element for generating circularly polarized electromagnetic signals, comprising: a single elongated excitation aperture cut in a planar conductive ground plane; in spaced parallel relation to the ground plane and completely covering the excitation aperture when viewed from a direction orthogonal to the ground plane, a planar conductive radiating patch havng slightly different dimensions along each of two orthogonal axes, with each said dimension being greater than the length of the excitation aperture; and a first planar dielectric layer separating the ground plane and the aperture from the radiating patch; wherein the excitation aperture forms an angle of substantially 45°, viewed from a direction orthogonal to the plane of the radiating patch, with respect to each of the two orthogonal axes of the radiating patch; whereby exciting the aperture with linearly polarized electromagnetic energy causes the radiating patch to generate a circularly polarized electromagnetic signal consisting of two orthogonal cmponents that have substantially the same amplitude and are 90°offset in phase from each other.