WO1990007201A1 - Improved feed waveguide for an array antenna - Google Patents

Improved feed waveguide for an array antenna Download PDF

Info

Publication number
WO1990007201A1
WO1990007201A1 PCT/US1989/005145 US8905145W WO9007201A1 WO 1990007201 A1 WO1990007201 A1 WO 1990007201A1 US 8905145 W US8905145 W US 8905145W WO 9007201 A1 WO9007201 A1 WO 9007201A1
Authority
WO
WIPO (PCT)
Prior art keywords
slot
waveguide
feed
longitudinal axis
feed waveguide
Prior art date
Application number
PCT/US1989/005145
Other languages
French (fr)
Inventor
Louis A. Kurtz
Original Assignee
Hughes Aircraft Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes Aircraft Company filed Critical Hughes Aircraft Company
Priority to JP2500436A priority Critical patent/JPH0834381B2/en
Publication of WO1990007201A1 publication Critical patent/WO1990007201A1/en
Priority to NO903493A priority patent/NO175126C/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/061—Two dimensional planar arrays
    • H01Q21/064—Two dimensional planar arrays using horn or slot aerials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
    • H01Q13/20—Non-resonant leaky-waveguide or transmission-line antennas; Equivalent structures causing radiation along the transmission path of a guided wave
    • H01Q13/22—Longitudinal slot in boundary wall of waveguide or transmission line
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/0006—Particular feeding systems
    • H01Q21/0037—Particular feeding systems linear waveguide fed arrays
    • H01Q21/0043—Slotted waveguides
    • H01Q21/005—Slotted waveguides arrays

Definitions

  • the present invention relates to slot array antennas. More specifically, the present invention relates to an improved feed for a slot array antenna.
  • Planar array antennas are used for a wide variety of radar applications.
  • One such planar array antenna is a flat plate antenna.
  • a flat plate antenna is typically a family of coplanar linear arrays each containing a series of resonant slot radiating apertures.
  • Microwave energy is provided to the radiating waveguides by a feed waveguide which is in turn fed by an input waveguide.
  • Slot coupling is a desirable technique for coupling energy from the feed waveguide to the radiating waveguides for most applications.
  • Slot coupling for a single feed, involves communication of energy through a slot in a broadwall of a rectangular feed waveguide and • slots in a broadwall of a rectangular radiating waveguide.
  • Energy is typically provided to the feed waveguide by an input waveguide located at either end of the feed waveguide or somewhere along the length thereof.
  • the location of the input waveguide at the ends of the feed waveguide may limit the bandwidth of the system or be otherwise problematic because of the relative inaccessibil ⁇ ity of the ends of the feed waveguides.
  • the center feeding of the feed waveguide is adjustable ⁇ tic with respect to the location of the input slot of the input waveguide relative to the feed slot of the feed wave ⁇ guide. That is, if, as is common, the input slot and the feed slots are placed on opposite broad walls of the feed waveguide and at one-quarter wavelength spacing down the waveguide, an impedance inversion results on each half of the feed waveguide which must be corrected in the design.
  • a common technique for correcting the impedance inversion involves a design in which coupling slots are at greater angles. Unfortunately, this approach typically results in larger coupling junction phase errors.
  • the improved feed waveguide of the present invention includes first and second slotted parallel walls.
  • the first wall includes a first elongate slot along a first longitudinal axis.
  • the second wall includes a second elongate slot located on the second wall opposite the first slot on the first wall.
  • the second slot has a second longitudinal axis.
  • the invention is adapted to provide a planar array antenna including at least one radiating waveguide having a first broadwall with a first elongate slot therethrough and a first longitudinal axis.
  • a feed waveguide is coupled to the radiating waveguide and has first and second parallel walls along the length thereof.
  • the first wall has a second elongate slot therethrough which is in communication with the first slot in the radiating waveguide.
  • the second slot has a longitudinal axis and is aligned with the slot in the radiating waveguide.
  • a third slot is located in the second wall opposite the second slot in the first wall and has a second longitudinal axis.
  • An input waveguide is coupled to the feed waveguide and includes a broadwall with an elongate slot therethrough.
  • the slot in the input waveguide is in communication with the third slot in the feed waveguide.
  • the slot in the input waveguide has a longitudinal axis aligned with the longitudinal axis of the third slot.
  • the slot in the input waveguide is colocated with the slot in the radiating waveguide and orthogonal thereto. This arrangement mitigates impedance inversion and allows for optimum performance of an array antenna.
  • Fig. 1(a) is an illustrative representation of a top view of a section of a flat plate slot array antenna incorporating the principles of the present invention.
  • Fig. 1(b) is an illustrative representation of a sectional side view of a section of a flat plate slot array antenna incorporating the principles of the present invention.
  • Fig. 1(c) shows a side view of a feed waveguide in a section of a flat plate slot array antenna incorporating the principles of the present invention.
  • Fig. 2(a) shows a prior art feed waveguide wherein the feed waveguide is fed via an input slot on one wall of the waveguide which is located between a series of feed slots which lie on the opposite wall of the feed waveguide.
  • Fig. 2(b) shows a end view of the feed waveguide of
  • Fig. 2(a) shows the present invention feed waveguide wherein the feed waveguide is fed via an input slot on one wall of the feed waveguide and colocated with one of a series of feed slots on the opposite wall of the feed waveguide.
  • Fig. 4 is an expanded view showing the location of an input slot and a colocated feed slot in the feed waveguide of the present invention. DESCRIPTION OF THE INVENTION
  • Fig. 1(a) is a top view of a section of the flat plate slot array antenna 10, incorporating the principles of the present invention.
  • the section of the antenna 10 includes first, second and third radiating waveguides 17, 19 and 21, respectively, mounted orthogonal to a feed waveguide 15 in broadwall-to-broadwall relation.
  • Each waveguide may be of conventional fabrication, e.g., metal or other suitably conductive material.
  • the radiating waveguides 17, 19 and 21 are spaced along the longitudinal axis of the feed waveguide 15 and coupled thereto by a plurality of inclined slots (shown in phantom) 25, 27 and 29 respectively.
  • the radiating waveguides 17, 19 and 21 are spaced so that they lie directly next to one another.
  • each radiating waveguide is rectangular having first and second broadwalls and first and second sidewalls.
  • the second radiating waveguide 19 has first and second broadwalls 35 and 50 and first and second sidewalls 51 and 52.
  • the feed waveguide 15 includes a front broadwall 35, a back broadwall 37 and side walls 46 and 48. (See the end view of Fig. 1(c).)
  • a rectangular input waveguide 23 is mounted on the back broadwall 37 of the feed waveguide 15 and includes a front broadwall 43, a back broadwall 32 and sidewalls 38 and 40.
  • the radiating waveguides 17, 19, and 21 are mounted on the front broadwall 35 of the feed waveguide 15.
  • the feed waveguide 15 is coupled to the radiating waveguides by a plurality of elongate inclined feed slots 25, 27, and 30, in the front broadwall 35 of the feed waveguide 15.
  • Each of the radiating waveguides 17, 19 and 21 contains a plurality of radiating slots which receive the energy from the feed slots 25, 27 and 29, respectively.
  • Each of the radiating slots are spaced one-half wavelength from each neighboring radiating slot.
  • the radiating waveguide 17 contains the radiating slots 71, 72, 73, 74, 75 and 76.
  • the radiating waveguide 19 contains the radiating slots 77, 78, 79, 80, 81 and 82.
  • the radiating waveguide 21 contains the radiating slots 83, 84, 85, 86, 87 and 88.
  • Each of the feed slots 25, 27 and 29 lie equidistant between two radiating slots. Thus, there is a one-quarter wavelength spacing from each feed slot and the closest radiating slot.
  • Each feed slot 25, 27, and 30 is inclined with respect to a longitudinal axis 39 of the feed waveguide 15 and has a longitudinal axis 41, 44, and 45 respectively.
  • the feed slots 25, 27 and 29 are shown in phantom in Fig. 1(a) .
  • the feed waveguide 15 also includes an input slot 32 on the back wall 37 thereof.
  • the input slot 32 is provided by a slot 32f in the feed waveguide 15 and a slot 32 ⁇ in an input waveguide 23.
  • the input slot 32 is also inclined with respect to the longitudinal axis 39 of the feed waveguide 15 and has a longitudinal axis 42.
  • a particularly novel feature of the present invention is the colocation of the input slot 32 with the feed slot 27 along the longitudinal axis 39 of the feed waveguide 15.
  • the colocation of the input slot 32 relative to a feed slot 27 allows for the coupling of energy from the input waveguide 23 to the feed waveguide 15 without an impedance inversion.
  • the colocation of the input slot 32 with a feed slot 27 is permitted by the orthogonal arrangement of the input slot 32 relative to the feed slot 27. That is, the longitudinal axis 42 of the input slot 32 is orthogonal " to the longitudinal axis 44 of the feed slot 27. (This is illustrated more clearly in phantom in Fig. 1(a) .)
  • energy is provided to the feed waveguide 15 by the input waveguide 23 via the slot 32.
  • the feed waveguide 15 then couples the energy to the radiating waveguides 17, 19 and 21 via slots 25, 27 and 29 on the broadwall 35.
  • the energy is then radiated to the atmosphere by the radiating waveguides 17, 19 and 21 in a conventional manner.
  • Fig. 2(a) is an illustrative representation of a conventional feed waveguide 15 • which is f d via an input slot 32' located between the ends of the feed waveguide 15'.
  • Fig. 2(b) is a side view of the conventional feed waveguide 15' showing the front and back broadwalls 35' and 37', respectively.
  • the conventional feed waveguide 15' includes a plurality of feed slots 25', 27', 29', on the front broadwall 35' of the feed waveguide 15' inclined with respect to the longitudinal axis 39' thereof and the input slot 32 ' (shown in phantom) on the back broadwall 37' of the feed waveguide 15'.
  • the input slot 32' has a longitudinal axis 70 which is generally normal to the longitudinal axis 39' of the feed waveguide 15' .
  • the two feed slots 25' and 27' are generally separated by a distance of one half of the wavelength of the operating frequency.
  • the input slot 32' is located on the back broadwall 37' of the feed waveguide 15' between two feed slots 25' and 27* on the front broadwall 35' thereof.
  • the input slot 32' is located equidistant between the two feed slots 25' and 27' . There is therefore a one-quarter wavelength spacing between the input slot 32' and each of the two feed slots 25' and 27'.
  • the one-quarter wavelength spacing between the feed slots 25' and 27' and input slot 32' causes a one-quarter wave inversion in the characteristic impedance of the waveguide each half of the feed waveguide 15'. This has previously precluded the ' centerfeeding of feed waveguides for many conventional planar array antennas.
  • an alternate conventional method of feeding the waveguide 15' is via either end of the feed waveguide 15'.
  • the advantage of the design is that impedance inversion is avoided.
  • the location of the input waveguide at the ends of the feed waveguide 15' may limit the bandwidth of the system or be otherwise problematic because of the relative inaccessibility of the ends of the feed waveguide 15* .
  • Fig. 3 is top view of the feed waveguide 15 constructed in .accordance with the principles of the present invention.
  • the input slot 32 is colocated with a feed slot 27 and orthogonal thereto. The is effective to mitigate the impedance inversion. A direct consequence of which is that smaller values of coupling slot angles can be used which, in turn, reduces coupling junction phase errors.
  • the expanded view of Fig. 4 better illustrates the advantageous location of an input slot 32 and a colocated feed slot 27 of a section of a feed waveguide 15 of the present invention.
  • the input slot 32 is shown in phantom to indicate that it is located on the bottom broadwall 37 of the feed waveguide 15.
  • the feed slot 27 is located on the top broadwall 35 of the feed waveguide 15.
  • Both the input slot 32 and the feed slot 27 are inclined with respect to the longitudinal axis 39 of the feed waveguide 15.
  • the input slot 32 has a longitudinal axis 42 which is orthogonal to the longitudinal axis 44 of the feed slot 27.
  • the input slot 32 couples energy from an input waveguide to the feed waveguide 15.
  • the feed slot 27 couples energy from the feed waveguide 15 to a radiating waveguide.

Landscapes

  • Waveguide Aerials (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

An improved feed waveguide (15) for an antenna (10) is disclosed which reduces coupling junction phase errors. The improved feed waveguide (15) of the present invention includes first and second slotted parallel walls (35) and (37) along the length thereof. The first wall (35) includes a first elongate slot (27) therethrough having a first longitudinal axis (44). The second wall (37) includes a second elongate slot (32) which is located on the second wall (37) opposite the first slot (27) on the first wall (35). The second slot (32) has a longitudinal axis (42) which is orthogonal to the longitudinal axis (44) of the first slot (27).

Description

IMPROVED FEED WAVEGUIDE FOR AN ARRAY ANTENNA
BACKGROUND OF THE INVENTION
Field of the Invention:
The present invention relates to slot array antennas. More specifically, the present invention relates to an improved feed for a slot array antenna.
While the present invention is described herein with reference to an illustrative embodiment for a particular application, it is understood that the invention is not limited thereto. Those of ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope thereof.
Description of the Related Art:
Planar array antennas are used for a wide variety of radar applications. One such planar array antenna is a flat plate antenna. A flat plate antenna is typically a family of coplanar linear arrays each containing a series of resonant slot radiating apertures. Microwave energy is provided to the radiating waveguides by a feed waveguide which is in turn fed by an input waveguide.
Slot coupling is a desirable technique for coupling energy from the feed waveguide to the radiating waveguides for most applications. Slot coupling, for a single feed, involves communication of energy through a slot in a broadwall of a rectangular feed waveguide and • slots in a broadwall of a rectangular radiating waveguide. Energy is typically provided to the feed waveguide by an input waveguide located at either end of the feed waveguide or somewhere along the length thereof.
The location of the input waveguide at the ends of the feed waveguide may limit the bandwidth of the system or be otherwise problematic because of the relative inaccessibil¬ ity of the ends of the feed waveguides.
The center feeding of the feed waveguide is problema¬ tic with respect to the location of the input slot of the input waveguide relative to the feed slot of the feed wave¬ guide. That is, if, as is common, the input slot and the feed slots are placed on opposite broad walls of the feed waveguide and at one-quarter wavelength spacing down the waveguide, an impedance inversion results on each half of the feed waveguide which must be corrected in the design. A common technique for correcting the impedance inversion involves a design in which coupling slots are at greater angles. Unfortunately, this approach typically results in larger coupling junction phase errors.
Location of the input slots on the opposite broadwall at the same position along the length of the feed waveguide as the feed slots has heretofore been avoided because of difficulty in achieving independent coupling of the input slot and the opposite feed slot.
There is therefore a need in the art for a planar array antenna feed waveguide which has an input slot located between the ends of the waveguide but does not have any associated impedance inversion.
SUBSTITUTE SHffiT SUMMARY OF THE INVENTION
The need in the art for a feed waveguide design that reduces coupling junction phase errors is addressed by the improved feed waveguide of the present invention. The improved feed waveguide of the present invention includes first and second slotted parallel walls. The first wall includes a first elongate slot along a first longitudinal axis. The second wall includes a second elongate slot located on the second wall opposite the first slot on the first wall. The second slot has a second longitudinal axis.
In a particular embodiment, the invention is adapted to provide a planar array antenna including at least one radiating waveguide having a first broadwall with a first elongate slot therethrough and a first longitudinal axis. A feed waveguide is coupled to the radiating waveguide and has first and second parallel walls along the length thereof. The first wall has a second elongate slot therethrough which is in communication with the first slot in the radiating waveguide. The second slot has a longitudinal axis and is aligned with the slot in the radiating waveguide. A third slot is located in the second wall opposite the second slot in the first wall and has a second longitudinal axis. An input waveguide is coupled to the feed waveguide and includes a broadwall with an elongate slot therethrough. The slot in the input waveguide is in communication with the third slot in the feed waveguide. The slot in the input waveguide has a longitudinal axis aligned with the longitudinal axis of the third slot. Thus, in accordance with the present teachings, the slot in the input waveguide is colocated with the slot in the radiating waveguide and orthogonal thereto. This arrangement mitigates impedance inversion and allows for optimum performance of an array antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1(a) is an illustrative representation of a top view of a section of a flat plate slot array antenna incorporating the principles of the present invention.
Fig. 1(b) is an illustrative representation of a sectional side view of a section of a flat plate slot array antenna incorporating the principles of the present invention. Fig. 1(c) shows a side view of a feed waveguide in a section of a flat plate slot array antenna incorporating the principles of the present invention.
Fig. 2(a) shows a prior art feed waveguide wherein the feed waveguide is fed via an input slot on one wall of the waveguide which is located between a series of feed slots which lie on the opposite wall of the feed waveguide.
Fig. 2(b) shows a end view of the feed waveguide of
Fig. 2(a) . Fig. 3 shows the present invention feed waveguide wherein the feed waveguide is fed via an input slot on one wall of the feed waveguide and colocated with one of a series of feed slots on the opposite wall of the feed waveguide. Fig. 4 is an expanded view showing the location of an input slot and a colocated feed slot in the feed waveguide of the present invention. DESCRIPTION OF THE INVENTION
Fig. 1(a) is a top view of a section of the flat plate slot array antenna 10, incorporating the principles of the present invention. The section of the antenna 10 includes first, second and third radiating waveguides 17, 19 and 21, respectively, mounted orthogonal to a feed waveguide 15 in broadwall-to-broadwall relation. Each waveguide may be of conventional fabrication, e.g., metal or other suitably conductive material. The radiating waveguides 17, 19 and 21 are spaced along the longitudinal axis of the feed waveguide 15 and coupled thereto by a plurality of inclined slots (shown in phantom) 25, 27 and 29 respectively. The radiating waveguides 17, 19 and 21 are spaced so that they lie directly next to one another.
As shown in the sectional side view of Fig. 1(b), each radiating waveguide is rectangular having first and second broadwalls and first and second sidewalls. For example, the second radiating waveguide 19 has first and second broadwalls 35 and 50 and first and second sidewalls 51 and 52. Similarly, the feed waveguide 15 includes a front broadwall 35, a back broadwall 37 and side walls 46 and 48. (See the end view of Fig. 1(c).) A rectangular input waveguide 23 is mounted on the back broadwall 37 of the feed waveguide 15 and includes a front broadwall 43, a back broadwall 32 and sidewalls 38 and 40. The radiating waveguides 17, 19, and 21 are mounted on the front broadwall 35 of the feed waveguide 15. The feed waveguide 15 is coupled to the radiating waveguides by a plurality of elongate inclined feed slots 25, 27, and 30, in the front broadwall 35 of the feed waveguide 15. Each of the radiating waveguides 17, 19 and 21 contains a plurality of radiating slots which receive the energy from the feed slots 25, 27 and 29, respectively. Each of the radiating slots are spaced one-half wavelength from each neighboring radiating slot. The radiating waveguide 17 contains the radiating slots 71, 72, 73, 74, 75 and 76. The radiating waveguide 19 contains the radiating slots 77, 78, 79, 80, 81 and 82.' The radiating waveguide 21 contains the radiating slots 83, 84, 85, 86, 87 and 88. Each of the feed slots 25, 27 and 29 lie equidistant between two radiating slots. Thus, there is a one-quarter wavelength spacing from each feed slot and the closest radiating slot. Each feed slot 25, 27, and 30 is inclined with respect to a longitudinal axis 39 of the feed waveguide 15 and has a longitudinal axis 41, 44, and 45 respectively. The feed slots 25, 27 and 29 are shown in phantom in Fig. 1(a) .
The feed waveguide 15 also includes an input slot 32 on the back wall 37 thereof. The input slot 32 is provided by a slot 32f in the feed waveguide 15 and a slot 32^ in an input waveguide 23. The input slot 32 is also inclined with respect to the longitudinal axis 39 of the feed waveguide 15 and has a longitudinal axis 42. As discussed below, a particularly novel feature of the present invention is the colocation of the input slot 32 with the feed slot 27 along the longitudinal axis 39 of the feed waveguide 15. The colocation of the input slot 32 relative to a feed slot 27 allows for the coupling of energy from the input waveguide 23 to the feed waveguide 15 without an impedance inversion. The colocation of the input slot 32 with a feed slot 27 is permitted by the orthogonal arrangement of the input slot 32 relative to the feed slot 27. That is, the longitudinal axis 42 of the input slot 32 is orthogonal "to the longitudinal axis 44 of the feed slot 27. (This is illustrated more clearly in phantom in Fig. 1(a) .) Thus, energy is provided to the feed waveguide 15 by the input waveguide 23 via the slot 32. The feed waveguide 15 then couples the energy to the radiating waveguides 17, 19 and 21 via slots 25, 27 and 29 on the broadwall 35. The energy is then radiated to the atmosphere by the radiating waveguides 17, 19 and 21 in a conventional manner.
The advantageous design of the improved feed technique of the present invention is appreciated with reference to the conventional feed arrangement of Fig. 2(a). Fig. 2(a) is an illustrative representation of a conventional feed waveguide 15 • which is f d via an input slot 32' located between the ends of the feed waveguide 15'. Fig. 2(b) is a side view of the conventional feed waveguide 15' showing the front and back broadwalls 35' and 37', respectively. The conventional feed waveguide 15' includes a plurality of feed slots 25', 27', 29', on the front broadwall 35' of the feed waveguide 15' inclined with respect to the longitudinal axis 39' thereof and the input slot 32 ' (shown in phantom) on the back broadwall 37' of the feed waveguide 15'. The input slot 32' has a longitudinal axis 70 which is generally normal to the longitudinal axis 39' of the feed waveguide 15' . The two feed slots 25' and 27' are generally separated by a distance of one half of the wavelength of the operating frequency. The input slot 32' is located on the back broadwall 37' of the feed waveguide 15' between two feed slots 25' and 27* on the front broadwall 35' thereof. The input slot 32' is located equidistant between the two feed slots 25' and 27' . There is therefore a one-quarter wavelength spacing between the input slot 32' and each of the two feed slots 25' and 27'. The one-quarter wavelength spacing between the feed slots 25' and 27' and input slot 32' causes a one-quarter wave inversion in the characteristic impedance of the waveguide each half of the feed waveguide 15'. This has previously precluded the ' centerfeeding of feed waveguides for many conventional planar array antennas.
As mentioned in the Background of the Invention, an alternate conventional method of feeding the waveguide 15' is via either end of the feed waveguide 15'. The advantage of the design is that impedance inversion is avoided. However, as previously discussed, the location of the input waveguide at the ends of the feed waveguide 15' may limit the bandwidth of the system or be otherwise problematic because of the relative inaccessibility of the ends of the feed waveguide 15* .
Fig. 3 is top view of the feed waveguide 15 constructed in .accordance with the principles of the present invention. As mentioned above, the input slot 32 is colocated with a feed slot 27 and orthogonal thereto. The is effective to mitigate the impedance inversion. A direct consequence of which is that smaller values of coupling slot angles can be used which, in turn, reduces coupling junction phase errors.
The expanded view of Fig. 4 better illustrates the advantageous location of an input slot 32 and a colocated feed slot 27 of a section of a feed waveguide 15 of the present invention. The input slot 32 is shown in phantom to indicate that it is located on the bottom broadwall 37 of the feed waveguide 15. The feed slot 27 is located on the top broadwall 35 of the feed waveguide 15. Both the input slot 32 and the feed slot 27 are inclined with respect to the longitudinal axis 39 of the feed waveguide 15. The input slot 32 has a longitudinal axis 42 which is orthogonal to the longitudinal axis 44 of the feed slot 27. The input slot 32 couples energy from an input waveguide to the feed waveguide 15. The feed slot 27 couples energy from the feed waveguide 15 to a radiating waveguide. Those skilled in the art will appreciate that an improved feed waveguide design has been disclosed which provides a reduction of coupling junction phase errors. Although the present invention has been described with reference to a particular illustrative embodiments for particular illustrative applications, those of ordinary skill in the art, having access to the present teachings, will recognize additional modifications,, applications, and embodiments within the scope thereof. For example, the number and orientations of the inclined slots is not critical to the invention. And while the invention is described with reference to a planar array antenna, the present invention is not limited thereto. The feed arrangement of the present invention is also advantageous in a linear array antenna such as a small Ka-band flat plate antenna. In addition, common forms of input slot excitation may be utilized in connection with present teachings.
It is intended by the appended Claims to cover any and all such modifications, applications, and embodiments within the scope of the invention. Accordingly,
WHAT IS CLAIMED IS:

Claims

1. An improved feed waveguide for an array antenna comprising: a waveguide having first and second slotted parallel walls along the length thereof, said first wall including a first elongate slot therethrough having a first longitudinal axis and said second wall including a second elongate slot therethrough, having a second longitudinal axis, located on said second wall opposite said first slot on said first wall.
2. The improved feed waveguide of Claim 1 wherein said longitudinal axis of said second elongate slot is orthogonal to the said longitudinal axis of said first elongate slot.
3. The improved feed waveguide of Claim 1 wherein said feed waveguide includes a plurality of elongate slots on said first wall.
4. A planar array antenna comprising: at least one radiating waveguide having a first broadwall with a first elongate slot therethrough having a first longitudinal axis; a feed waveguide having first and second parallel walls along the length thereof, said first wall having a second elongate slot therethrough in communication with said first slot and having a longitudinal axis aligned with said first longitudinal axis and said second wall having a third elongate slot therethrough located opposite said second slot having a second longitudinal axis; and an input waveguide having a broadwall with an elongate slot therethrough in communication with said second slot and having a longitudinal axis aligned with said second longitudinal axis .
5. The improved feed waveguide of Claim 4 wherein said longitudinal axis of said second elongate slot in s a id input waveguide i s orthogona l to the s aid longitudinal axis of said first second slot.
PCT/US1989/005145 1988-12-20 1989-11-15 Improved feed waveguide for an array antenna WO1990007201A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2500436A JPH0834381B2 (en) 1988-12-20 1989-11-15 Planar array antenna
NO903493A NO175126C (en) 1988-12-20 1990-08-08 Food waveguide for a group antenna

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US28736488A 1988-12-20 1988-12-20
US287,364 1988-12-20

Publications (1)

Publication Number Publication Date
WO1990007201A1 true WO1990007201A1 (en) 1990-06-28

Family

ID=23102576

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1989/005145 WO1990007201A1 (en) 1988-12-20 1989-11-15 Improved feed waveguide for an array antenna

Country Status (7)

Country Link
EP (1) EP0404905A1 (en)
JP (1) JPH0834381B2 (en)
KR (1) KR920009224B1 (en)
CA (1) CA2003471C (en)
ES (1) ES2019761A6 (en)
IL (1) IL92766A0 (en)
WO (1) WO1990007201A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991017586A1 (en) * 1990-04-30 1991-11-14 Commonwealth Scientific And Industrial Research Organisation A flat plate antenna
AU639563B2 (en) * 1990-04-30 1993-07-29 Commonwealth Scientific And Industrial Research Organisation A flat plate antenna
RU2755338C1 (en) * 2020-10-12 2021-09-15 Российская Федерация, от имени которой выступает Министерство обороны Российской Федерации Waveguide-slot radiator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4869766B2 (en) * 2006-04-12 2012-02-08 日本無線株式会社 Slot antenna
JP4772704B2 (en) * 2007-01-15 2011-09-14 三菱電機株式会社 Antenna device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1933950A1 (en) * 1968-07-05 1970-01-15 Thomson Csf Arrangement for exciting a waveform H20 in a rectangular waveguide as well as monoplus source containing this arrangement
GB1180714A (en) * 1967-06-27 1970-02-11 North American Rockwell A Crossed Guide Directional Coupler
US4429313A (en) * 1981-11-24 1984-01-31 Muhs Jr Harvey P Waveguide slot antenna
WO1986003062A1 (en) * 1984-11-08 1986-05-22 Hughes Aircraft Company Modularized contoured beam direct radiating antenna
US4821044A (en) * 1987-04-14 1989-04-11 Hughes Aircraft Company Waveguide slot array termination and antenna system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1180714A (en) * 1967-06-27 1970-02-11 North American Rockwell A Crossed Guide Directional Coupler
DE1933950A1 (en) * 1968-07-05 1970-01-15 Thomson Csf Arrangement for exciting a waveform H20 in a rectangular waveguide as well as monoplus source containing this arrangement
US4429313A (en) * 1981-11-24 1984-01-31 Muhs Jr Harvey P Waveguide slot antenna
WO1986003062A1 (en) * 1984-11-08 1986-05-22 Hughes Aircraft Company Modularized contoured beam direct radiating antenna
US4821044A (en) * 1987-04-14 1989-04-11 Hughes Aircraft Company Waveguide slot array termination and antenna system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991017586A1 (en) * 1990-04-30 1991-11-14 Commonwealth Scientific And Industrial Research Organisation A flat plate antenna
AU639563B2 (en) * 1990-04-30 1993-07-29 Commonwealth Scientific And Industrial Research Organisation A flat plate antenna
RU2755338C1 (en) * 2020-10-12 2021-09-15 Российская Федерация, от имени которой выступает Министерство обороны Российской Федерации Waveguide-slot radiator

Also Published As

Publication number Publication date
CA2003471C (en) 1995-05-09
JPH0834381B2 (en) 1996-03-29
CA2003471A1 (en) 1990-06-20
KR920009224B1 (en) 1992-10-15
ES2019761A6 (en) 1991-07-01
JPH03503826A (en) 1991-08-22
IL92766A0 (en) 1990-09-17
KR910700552A (en) 1991-03-15
EP0404905A1 (en) 1991-01-02

Similar Documents

Publication Publication Date Title
US6208308B1 (en) Polyrod antenna with flared notch feed
US5210543A (en) Feed waveguide for an array antenna
EP0747994B1 (en) Dual polarization common aperture array formed by a waveguide-fed, planar slot array and a linear short backfire array
US6166701A (en) Dual polarization antenna array with radiating slots and notch dipole elements sharing a common aperture
US5019831A (en) Dual end resonant slot array antenna feed having a septum
US4839663A (en) Dual polarized slot-dipole radiating element
EP0565051B1 (en) Wideband arrayable planar radiator
US20020067315A1 (en) Aperture coupled slot array antenna
GB2208969A (en) Slot antenna
US5995055A (en) Planar antenna radiating structure having quasi-scan, frequency-independent driving-point impedance
US5650793A (en) Centered longitudinal series/series coupling slot for coupling energy between a boxed stripline and a crossed rectangular waveguide and antenna array employing same
US7576703B1 (en) Parallel waveguide slot coupler with reactive buffering region
US6201507B1 (en) Centered longitudinal shunt slot fed by a resonant offset ridge iris
US5543810A (en) Common aperture dual polarization array fed by rectangular waveguides
US2718592A (en) Antenna
JPS6230409A (en) Slot array antenna unit
WO1990007201A1 (en) Improved feed waveguide for an array antenna
US5170174A (en) Patch-excited non-inclined radiating slot waveguide
US6781554B2 (en) Compact wide scan periodically loaded edge slot waveguide array
US3189908A (en) Ridged waveguide slot antenna
US6181291B1 (en) Standing wave antenna array of notch dipole shunt elements
US4435715A (en) Rod-excited waveguide slot antenna
EP0434283B1 (en) Planar array waveguide antenna with L-shaped series/series coupling slots
JPS6030441B2 (en) Dual frequency band shared phase shifter
US5467101A (en) Waveguide antenna with transversal slots

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP KR NO

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): CH DE FR GB IT NL SE

WWE Wipo information: entry into national phase

Ref document number: 1990900491

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1990900491

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1990900491

Country of ref document: EP