Ridged horn antenna having additional corrugation

Abstract

A radiating element may comprise an antenna element, a radiating element edge, and a corrugation. The antenna element may have an aperture that extends into the antenna element, and an aperture side defining an aperture area of the antenna element. The radiating element edge may surround the antenna element on the aperture side. The corrugation may be configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge. The radiating element edge may be connected to the antenna element at a distance greater than zero from the aperture side of the antenna element.

Claims

1. A radiating element for an antenna system comprising: an antenna element having an aperture that extends into the antenna element, wherein the antenna element includes: an aperture side defining an aperture area of the antenna element; and at least two ridges which are each oriented about a center of the antenna element and are arranged in crosswise orientation with respect to the center of the antenna element; a radiating element edge defining a rectangular contour that surrounds the antenna element on the aperture side; and a single corrugation configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge; wherein: the radiating element edge is connected to the antenna element at a distance greater than zero from the aperture side of the antenna element; a width of the radiating element is less than , where is a wavelength of a center frequency in a used frequency band; and the antenna element is centrally arranged within the contour.

2. The radiating element according to claim 1, wherein the corrugation has walls substantially perpendicular to the aperture area.

3. The radiating element according to claim 1, wherein the radiating element edge defines a square contour of the radiating element.

4. The radiating element according to claim 1, wherein a contour of the antenna element comprises ridges on a groove side pointing away from a center of the antenna element.

5. The radiating element according to claim 1, wherein the antenna element comprises a matching step.

6. The radiating element according to claim 5, wherein the matching step of the antenna element is formed at a same distance from the aperture area as from a connection of the radiating element edge and the antenna element.

7. The radiating element according to claim 1, wherein a distance between the aperture area and a connection of the radiating element edge and the antenna element is /4, where is a wavelength of a center frequency in a used frequency band.

8. The radiating element according to claim 1, wherein a distance between the aperture area and a connection of the radiating element edge and the antenna element varies along the corrugation.

9. The radiating element according to claim 8, wherein the distance is the same on opposing sides of the radiating element edge.

10. The radiating element according to claim 1, further comprising: a microstrip configured to couple signals into the antenna element.

11. The radiating element according to claim 1, further comprising: two microstrips configured to couple signal components into the antenna element, wherein the signal components are orthogonally polarized with respect to each other.

12. The radiating element according to claim 11, wherein: a short-circuited end of the antenna element has a ridge that is aligned with a polarization and has a ridge length; a distance between the two microstrips approximately equals the ridge length; and a distance between one of the two microstrips and the short-circuited end, and a distance between another one of the two microstrips and the ridge, each approximately equals /4, where is a wavelength of a center frequency in a used frequency band.

13. The radiating element according to claim 1, wherein the antenna element is filled with a dielectric.

14. An antenna system comprising: a plurality of radiating elements, each of the radiating elements comprising: an antenna element having an aperture that extends into the antenna element, wherein the antenna element includes: an aperture side defining an aperture area of the antenna element; and at least two ridges which are each oriented about a center of the antenna element and are arranged in crosswise orientation with respect to the center of the antenna element; a radiating element edge that surrounds the antenna element on the aperture side; and a single corrugation configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge; wherein: the radiating element edge is connected to the antenna element at a distance greater than zero from the aperture side of the antenna element; and a width of the radiating element is less than , where is a wavelength of a center frequency in a used frequency band; and a microstrip network configured to feed signals to radiating elements, wherein neighboring single radiating elements have a shared edge.

15. The antenna system according to claim 14, wherein the antenna system is configured to operate bidirectionally in vehicle-based satellite communication in at least one of an X, Ka, or Ku band.

16. A radiating element for an antenna system comprising: an antenna element comprising a short-circuited end and an aperture extending into the antenna element, wherein the antenna element has an aperture side defining an aperture area of the antenna element; a radiating element edge that surrounds the antenna element on the aperture side; and a corrugation configured to separate, at least on the aperture side, the antenna element and the surrounding radiating element edge; and two microstrips configured to couple signal components into the antenna element, wherein the signal components are orthogonally polarized with respect to each other wherein: the radiating element edge is connected to the antenna element at a distance greater than zero from the aperture side of the antenna element; the short-circuited end has a ridge having a ridge length, the ridge being aligned with a polarization; a distance between the two microstrips approximately equals the ridge length; and a distance between one of the two microstrips and the short-circuited end, and a distance between another one of the two microstrips and the ridge, each approximately equals /4, where is a wavelength of a center frequency in a used frequency band.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a top view onto a single radiating element according to an embodiment of the present disclosure;

(2) FIG. 2 shows a sectional view of a single radiating element according to an embodiment of the present disclosure;

(3) FIG. 3 shows an electric field distribution of a single radiating element in an antenna comprising periodically arranged single radiating elements;

(4) FIG. 4 shows a top view onto an alternative single radiating element according to an embodiment of the present disclosure; and

(5) FIG. 5 shows an antenna comprising multiple single radiating elements and a feed network.

DETAILED DESCRIPTION

(6) FIG. 1 shows a single radiating element having a square contour, which may be formed by a horn antenna edge R, according to an embodiment of the present disclosure. A ridged horn antenna A1 may be arranged centrally within the contour of the single radiating element. The ridged horn antenna A1 itself may have a substantially square shape with slightly rounded corners and curvatures, which will be described hereafter in the embodiment according to FIG. 4. The ridged horn antenna A1 may be separated from the horn antenna edge R by a corrugation N, which itself can have a substantially square shape and, like the ridged horn antenna A1, can be filled with air. Surfaces of the ridged horn antenna A1, the corrugation N, and the horn antenna edge R may form the aperture area a.

(7) The ridged horn antenna A1 can be characterized by four ridges S1 to S4, which may be arranged crosswise and in the direction of a ridged horn antenna center M. The single radiating element may therefore be able to support two polarizations located perpendicularly on each other. Each of the two ridge pairs S1 and S3, and S2 and S4, formed from two opposing ridges, can support one polarization. As is additionally described in FIG. 2, two microstrips MS1 and MS2 may be located in the interior of the ridged horn antenna A1, may couple high-frequency signals into the ridged horn antenna A1 when sending takes place, and may couple the signals out of the ridged horn antenna A1 when receiving takes place.

(8) A radiation pattern of the single radiating element may be formed by the superimposition of signals of the ridged horn antenna A1 and the corrugation N, as described hereafter. A portion of the signal leaving the ridged horn antenna A1 can be coupled into the corrugation N. At a corrugation depth of /4, with being the wavelength of the signal (in the case of broadband signals, approximately the center frequency of the bandwidth), the signal in the corrugation N can traverse 90 to the end of the corrugation N, can be rotated 180 at the end of the corrugation N by a short circuit (zero point), and can traverse the 90 back again to the aperture area a, where the signal may be added at 360 in phase to the signal from the ridged horn antenna A1. This may create a standing wave in the corrugation N.

(9) An embodiment of the single radiating element according to the present disclosure is shown in 3D form in FIG. 2, with the structures of the ridged horn antenna A1, corrugation N, and horn antenna edge R located perpendicularly on the aperture area. There may be a distance I between the connection of the ridged horn antenna A1 and horn antenna edge R forming the termination (short circuit) of the corrugation N and the aperture area a. The distance 1 may correspond approximately to /4. A matching step AP may be arranged within the ridged horn antenna A1 at approximately the same height as the depth (termination) of the corrugation N, with said ridged horn antenna A1 being further constricted in this step. Only one matching step AP may be provided in this ridged horn antenna.

(10) Lateral openings, through which the microstrips MS1, MS2 may be guided, may be introduced into the horn antenna edge R. The microstrips MS1, MS2 may be arranged parallel to the aperture area and perpendicularly to each other, and may be spaced from each other in the direction of the aperture area. The distance 1s between the microstrips MS1, MS2 may correspond to a length Is of an additional ridge S, which may be arranged at a short-circuited end AB of the ridged horn antenna A1 and may extend from there into the ridged horn antenna A1. The ridge S may be oriented so that it serves as a ridged horn antenna termination for the one of the polarizations. The microstrips MS1, MS2 may therefore each be arranged /4 from the ridge S or the short-circuited end AB of the ridged horn antenna A1.

(11) The microstrips MS1, MS2 may be composed of a suspended stripline (SSL), which may be made of a printed circuit board to which a copper strip (copper layer) is applied. The printed circuit board itself may be made of a dielectric having a thickness of 0.1 to 1 millimeters (mm), for example 0.127 mm. The copper strip located thereon may have a width of 0.3 to 1 mm, for example 0.5 mm, and may have a thickness of 15 to 20 micrometers (m), for example 17.5 m. The openings at the level of the incoupling may be shaped as narrow slots and may be adapted to the shape of the microstrip MS1, MS2 to allow the microstrips MS1, MS2 to protrude into the ridged horn antenna A1. The SSL may be surrounded by metal; therefore, there may be no power losses due to radiated emission out of the structure and as a result of the feedthrough at the slots. By appropriately dimensioning the slots, an interference effect on a field in the ridged horn antenna A1 may also remain negligible.

(12) FIG. 3 shows a simulated electric field distribution of the single radiating element of an antenna according to embodiments of the present disclosure, which may be composed of multiple single radiating elements in a periodic arrangement. The signals may be coupled into the ridged horn antenna A1 by the microstrip MS1 and reflected at the short-circuited end AB of the ridged horn antenna A1. The corrugation N may act as a reflector for the signal from the ridged horn antenna A1. Both the fields from the radiating ridged horn antenna A1, and the reflected components from the corrugation N, may be added to form a plane wavefront.

(13) FIG. 4 shows an alternative single radiating element according to embodiments of the present disclosure. This single radiating element may be used for antennas having circular polarization (using a meander-line polarizer) in the X band. For example, Rx may be 7.25 GHz to 7.75 GHz (LHCP), and Tx may be 7.90 GHz to 8.40 GHz (RHCP).

(14) The corrugation depth I1, I2 may vary. Opposing sections of the corrugation N may have the same depth I1 or I2. Depth I1 or I2 may be dimensioned as a function of the polarization supported by the neighboring sections of the horn antenna edge R. The stepped corrugation N may allow the two polarizations to be optimally matched frequency-selectively separate from each other. For each polarization, the corrugation N may be set to the different optimal /4. The single radiating element according to FIG. 4 moreover may comprise groove-side ridges s1 to s4, which may protrude from the ridged horn antenna in the direction of the corrugation N and may result in changes of the width of the corrugation N. In this way, undesirable resonances between modes of the waves from the ridged horn antenna and corrugation N may be shifted into frequency ranges in which the antenna is not operated.

(15) The single radiating element according to embodiments of the present disclosure may be used in antennas comprising multiple single radiating elements, which may be arranged in a shared aperture area. FIG. 5 shows an antenna comprising 16 single radiating elements. A feed network may be composed of microstrips MS1 and MS2, which can feed 8 single radiating elements A1 to A8. A waveguide HL may be arranged centrally within eight single radiating elements A1 to A8, and the signals may be coupled out in two microstrips MS1 and MS2 at the two narrow sides of the waveguide HL. These microstrips MS1 and MS2 in turn may form microstrip networks, which may connect 4 single radiating elements A1 to A4, or AS to A8, to the waveguide HL. The waveguide HL, in turn, may form the terminal of a waveguide network. Waveguide power splitters may be provided. The waveguide network, in turn, may be connected to a transceiver device Tx/Rx, which may receive corresponding signals from the antenna, or send signals to the antenna.

(16) The feed network having dual magnetic field incoupling may allow a large number of antenna elements to be fed with a minimum of power splitters in the waveguide network.

(17) By way of such feeding and using single radiating elements according to the present disclosure, light-weight compact antennas can be implemented.

LIST OF REFERENCE NUMERALS

(18) Aperture area a

(19) Microstrip MS1, MS2

(20) Ridged horn antenna A1, A2 to Ax

(21) Short-circuited end of ridged horn antenna AB

(22) Transceiver devices Tx/Rx

(23) Horn antenna edge R

(24) Corrugation N

(25) Depth of the corrugation I,I1,I2

(26) Ridges of ridged horn antenna S1 to S4

(27) Ridged horn antenna center M

(28) Matching step AP

(29) Waveguide HL

(30) Ridge at ridged horn antenna end S

(31) Ridge length Is

(32) Distance of the microstrips Is

(33) Groove-side ridges s1 to s4