HORN ANTENNA AND METHOD FOR RECONSTRUCTING A HORN ANTENNA

Abstract

A horn antenna for emitting an electromagnetic HPEM microwave pulse along a central axis contains a microwave generator for the pulse having a waveguide along the central axis with a generator opening for the pulse, and a horn structure for shaping the pulse with an input opening and an emission opening for the pulse. The generator contains at least one HPEM source for the pulse. Each HPEM source contains at least two antennas for pulse components, disposed in succession in parallel with the central axis. The pulse is formed as a sum of the pulse components. A method for reconstructing a horn antenna to form the horn antenna with increased power, includes constructively increasing a number of antennas toward a respective HPEM source and orienting remaining antennas in a row relative to the first antenna, increasing the waveguide length, and keeping other dimensions of the horn antenna unchanged.

Claims

1. A horn antenna for emitting an electromagnetic HPEM microwave pulse along a central axis, the horn antenna comprising: a microwave generator for generating the pulse, said microwave generator having a waveguide with a generator opening for outputting the pulse, said waveguide extending along the central axis; and a horn structure for shaping the pulse, said horn structure having an input opening serving to radiate the pulse, said input opening being connected to said generator opening, and said horn structure having an emission opening for emitting the shaped pulse; said microwave generator containing at least one HPEM source for generating the pulse; said at least one HPEM source containing at least two antennas disposed in succession in parallel with the central axis, said at least two antennas each serving to emit a respective pulse component; and the pulse being formed as a sum of said pulse components.

2. The horn antenna according to claim 1, wherein at least one of said antennas is at least one of an antenna rod or an antenna DS resonator or a feed or a dipole or a group.

3. The horn antenna according to claim 1, wherein said waveguide is a metallic body.

4. The horn antenna according to claim 1, wherein said waveguide is a body made of an electrically conductive material.

5. The horn antenna according to claim 1, wherein said waveguide has a cuboid shape.

6. The horn antenna according to claim 1, wherein at least one of said horn structure or said waveguide has a polygonal cross section relative to the central axis.

7. The horn antenna according to claim 1, wherein said at least two antennas are disposed together in one plane.

8. The horn antenna according to claim 1, wherein said at least two antennas include adjacent antennas of said at least one HPEM source being spaced apart from one another by identical spacings in at least one HPEM source.

9. The horn antenna according to claim 1, wherein said at least two antennas include adjacent antennas of said at least one HPEM source being spaced apart from one another by different spacings in at least one HPEM source.

10. The horn antenna according to claim 1, which further comprises a control unit configured: to drive an individual antenna of said at least two antennas to generate the pulse, or to drive an activation and a phase angle of respective pulse components of said at least two antennas, causing said pulse components of said at least two antennas to superpose and form the pulse along an emission direction directed parallel to the central axis toward said generator opening.

11. The horn antenna according to claim 10, wherein said control unit is configured to drive said at least two antennas individually or in a time-synchronous manner or with a time offset relative to an individual or a plurality of other antennas.

12. The horn antenna according to claim 10, wherein said control unit is configured to drive individual antennas of said at least two antennas in a burst mode with time lags.

13. The horn antenna according to claim 10, wherein said control unit is configured to drive said at least two antennas to cause wavefronts of said pulse components to superpose constructively in a wavefront of the pulse, in a direction of the central axis toward said emission opening.

14. A method for reconstructing a horn antenna to form a horn antenna according to claim 1 with increased power, the method comprising: proceeding from at least one respective first antenna: constructively increasing a number of antennas of a respective HPEM source and orienting remaining antennas of the respective HPEM source in a row relative to the at least one first antenna; increasing a length of the waveguide; and leaving other dimensions of the horn antenna unchanged.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0047] FIG. 1 is a diagrammatic, longitudinal-sectional view of a horn antenna according to the invention;

[0048] FIG. 2 is a fragmentary, longitudinal-sectional view showing a reconstruction of an existing horn antenna to form horn antennas according to the invention;

[0049] FIG. 3 is a fragmentary, longitudinal-sectional view showing geometric relationships and options for varying them on a horn antenna according to the invention; and

[0050] FIG. 4 is a group of elevational views showing a horn antenna according to the invention with a) one, b) two and c) four HPEM sources.

DETAILED DESCRIPTION OF THE INVENTION

[0051] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a horn antenna 2 during operation, specifically when emitting an electromagnetic HPEM microwave pulse 4. FIG. 1 illustrates superpositions of wavefronts of the pulse 4. The horn antenna 2 has a central axis 6, along which the pulse 4 is emitted. The horn antenna 2 contains a microwave generator 8 for generating the pulse 4. The generator 8 contains a waveguide 10. The waveguide 10 has a generator opening 12 for emitting the pulse 4. In this case, the waveguide 10 is a cuboid metallic body which has a rectangular cross section in relation to the central axis 6 (see FIG. 4) and extends along the central axis 6.

[0052] The horn antenna 2 additionally contains a horn structure 14 which serves to shape the pulse 4. The horn structure 14 has an input opening 16 which coincides with the generator opening 12, and an output opening 18 which serves to emit the shaped pulse 4.

[0053] In the illustrated example, the generator 8 contains a single HPEM source 20 (surrounded by dashes in the figure) for generating the pulse 4. The HPEM source 20 contains four antennas 22a-d, which are DS resonators in this case, and are disposed in succession and parallel to the central axis 6. Each of the antennas 22a-d serves to respectively emit a pulse component 24a-d. The pulse 4 at a given time is formed as the sum of the pulse components 24a-d generated at that time.

[0054] The antennas 22a-d are fed, in a manner which is not explained in any more detail, by pulse sources 26 of the generator 8. The pulse sources are driven by a control unit 28 of the generator 8. All four antennas 22a-d are disposed in a common plane.

[0055] In the example, the control unit 28 drives all four antennas 22a-d with respect to the activation and the phase angle of their respective pulse component 24a-d in such a way that the pulse components 24a-d of these antennas 22a-d superpose to form the pulse 4 so that its emission direction 30 is directed parallel to the central axis 6 toward the generator opening 12 or through and out from the latter. To this end, the antennas 22a-d are driven “in phase” or in phase-related fashion with a suitable time offset in relation to one another. Moreover, the driving is implemented in such a way that the wavefronts of the pulse components 24a-d superpose constructively in the wavefront of the pulse 4, in the direction of the central axis 6 toward the emission opening 18.

[0056] FIG. 2 shows a method for reconstructing or newly constructing an existing non-inventive horn antenna 32 to form horn antennas 2′ or 2″ according to the invention. The original horn antenna 32 has only a single antenna 22a. Otherwise the horn antenna 32 includes a generator 8 with a connected horn structure 14.

[0057] For reconstruction purposes, the number of antennas 22 is increased to two (22a, 22b) in the case of the horn antenna 2′ and to four (22a-22d) in the case of the horn antenna 2″. The one or three additional antennas are disposed in a row with respect to the first antenna 22a, the length of the waveguide 10 is increased but the remaining dimensions of the horn antenna 32 are maintained unchanged. The dashed line in FIG. 2 indicates that any other number of antennas greater than one can also be realized.

[0058] FIG. 3 symbolically shows options for varying the horn structure 14 and/or the waveguide 10 in a horn antenna 2 according to the invention, which can be undertaken empirically or in accordance with simulations or trials in order to optimize the emission of pulses 4. Without going into any detail in this respect, it is possible, inter alia, to vary a number N (four in this case) of the antennas 22, an opening angle α and/or a length L2 of the horn structure 14, an (also sectional) opening angle β and/or a length L1 of the waveguide 10, distances d between the antennas 22 and wall spacings D1, D2 of the antennas 22 from the walls of the waveguide 10. In the present example, the distances d between two adjacent antennas 22 in each case are chosen to be the same.

[0059] FIG. 4b illustrates further options for variation in the form of the height H and width B of the “horn” or of the emission opening 18, and the height h and width b of the waveguide 10 or of the generator opening 12 and the input opening 16. In this case, FIG. 4 shows frontal views overall of different horn antennas 2 (in the direction of an arrow IV in FIG. 3). In this case, FIG. 4A shows the situation of FIGS. 1-3, specifically with a single HPEM source 20. FIG. 4B shows, in one variant, two respective sources 20 (disposed above one another) of four antennas. FIG. 4C shows a variant of four sources 20 (a respective two next to one another and a respective two above one another) of four antennas.

[0060] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:

LIST OF REFERENCE SIGNS

[0061] 2 Horn antenna [0062] 4 HPEM microwave pulse [0063] 6 Central axis [0064] 8 Microwave generator [0065] 10 Waveguide [0066] 12 Generator opening [0067] 14 Horn structure [0068] 16 Input opening [0069] 18 Emission opening [0070] 20 HPEM source [0071] 22a-d Antenna [0072] 24a-d Pulse component [0073] 26 Pulse sources [0074] 28 Control unit [0075] 30 Emission direction [0076] 32 Horn antenna (non-inventive) [0077] α,β Opening angle [0078] H Height (horn) [0079] B Width (horn) [0080] h Height (waveguide) [0081] b Width (waveguide) [0082] L1 Length (waveguide) [0083] L2 Length (horn structure) [0084] d Distance (antennas) [0085] D1,2 Wall spacing