WO1999008338A1 - Microwave antenna having wide angle scanning capability - Google Patents

Microwave antenna having wide angle scanning capability Download PDF

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Publication number
WO1999008338A1
WO1999008338A1 PCT/US1998/016216 US9816216W WO9908338A1 WO 1999008338 A1 WO1999008338 A1 WO 1999008338A1 US 9816216 W US9816216 W US 9816216W WO 9908338 A1 WO9908338 A1 WO 9908338A1
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WO
WIPO (PCT)
Prior art keywords
antenna
scan
scanning line
line feeds
switching matrix
Prior art date
Application number
PCT/US1998/016216
Other languages
French (fr)
Inventor
Ronald I. Wolfson
William W. Milroy
Alan C. Lemons
Stuart B. Coppedge
Original Assignee
Raytheon 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 Raytheon Company filed Critical Raytheon Company
Priority to GB9907696A priority Critical patent/GB2334383B/en
Priority to ES009950016A priority patent/ES2152906B1/en
Priority to IL12923398A priority patent/IL129233A/en
Priority to DE19881296T priority patent/DE19881296B4/en
Priority to JP51225099A priority patent/JP3754091B2/en
Publication of WO1999008338A1 publication Critical patent/WO1999008338A1/en

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Classifications

    • 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
    • H01Q13/28—Non-resonant leaky-waveguide or transmission-line antennas; Equivalent structures causing radiation along the transmission path of a guided wave comprising elements constituting electric discontinuities and spaced in direction of wave propagation, e.g. dielectric elements or conductive elements forming artificial dielectric
    • 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
    • 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 generally to microwave antennas, and more particularly, to a microwave antenna having wide angle scanning capability.
  • Ferrite phase scanning antennas that radiate into free space are described in the technical literature. Ferrite phase scanning antennas are discussed in articles by Stern, et al. entitled “A mm- Wave Homogeneous Ferrite Phase Scan Antenna.” Microwave Journal. Vol. 30, No. 4, Apr. 1987, pp. 101-108, and U. S. Patent No. 4,691,208 entitled “Ferrite Waveguide Scanning Antenna", for example.
  • a ferrite scanning line feed is a device that is similar to the previously discussed scanning line feed, and has the same limitations in scan range. The distinction is that the line feed is specifically designed to radiate into a parallei-plate region of a planar array antenna, which may be either air or dielectrically filled. Further, the scanning line feed is designed using bidirectional array excitation synthesis to be fed from either end, producing two well-formed beams offset in space.
  • a major disadvantage of the prior art is the limited scan coverage that can be realized with ferrite phase scanned antennas at high millimeter-wave frequencies, typically on the order of from 40 GHz and above.
  • the present invention provides for a planar array antenna that uses two distributed ferrite scanning line feeds to feed a planar array antenna, such as a continuous transverse stub array.
  • the scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors.
  • the present invention does not require a multitude of line feeds that are scanned with discrete phase shifters such as is described in the Kinsey article. This reduction in complexity, combined with a 360° gimbal in the second axis, results in lower design and production costs for the antenna.
  • the use of dual ferrite scanning line feeds, a switching matrix, and a planar array antenna to obtain wide-angle scanning significantly improves the performance of continuous transverse stub (CTS) antennas and systems.
  • CTS continuous transverse stub
  • the present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter- wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability.
  • the scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, thereby increasing the angular scan coverage of the antenna at least fourfold.
  • the switching matrix is used to sequentially feed each of four RF ports to effectively produce a single beam that scans over the four contiguous scan sectors.
  • Fig. 2 illustrates how contiguous scan sectors covering over 60° are produced by switching between four RF ports
  • Figs. 3a and 3b illustrate a planar array antenna in accordance with the present invention edge-fed by two scanning line feeds;
  • Fig. 4 illustrates a switching matrix having three switching ferrite circulators;
  • Figs. 5 and 6 illustrate how scanning line feeds couple through a ground plane into the parallel-plate region of a continuous transverse stub array antenna
  • Fig. 7 illustrates a planar array antenna comprised of continuous transverse stub subarrays nested in a triangular lattice; and Figs. 8a and 8b show computed forward-fired and backward-fired beam patterns, respectively, of a 77 GHz line feed designed using a modified Woodward- Lawson synthesis.
  • Fig. 1 shows a graph illustrating the computed scan coverage versus frequency that is achievable for a typical conventional ferrite line scanner using state-of-the-art ferrite materials with the maximum saturation magnetization (4 ⁇ M s ) available, which is approximately 5,000 Gauss.
  • the graph of Fig. 1 is based on measured data of differential phase shift per inch at several millimeter-wave frequencies. Approximately 625 inch was obtained at 94 GHz. This produces only about 12.6 degrees of scan coverage, while as much as 60 degrees may be required for certain antenna applications.
  • Fig. 2 shows four contiguous scan sectors that are produced by the present invention that cover 0° to +12.6°, +12.6° to +25.8°, +25.8° to 440.8°, and 440.8° to +60.7°, respectively.
  • ⁇ personally Sin-' (n ⁇ /360), where: ⁇ n m ma,x r is the maximum scan ang "—le for a g>iven scan sector, n is the scan sector ( "• 1 through 4 for this example), ⁇ is the wavelength in air in inches (0.1256 inches for 94 GHz); and ⁇ is the differential phase shift in degrees per inch (625).
  • the present invention switches between multiple contiguous scan sectors as shown in Fig. 2 in order to increase the total angular scan coverage of a scanning antenna 10 (shown in Figs. 3a and 3b), and is believed to be unique as applied to a planar array scanning antenna 10, such as a continuous transverse stub antenna 11 developed by the assignee of the present invention.
  • the continuous transverse stub antenna 11 is described in U. S. Patent No. 5,266,961 assigned to the assignee of the present invention and the disclosure thereof is incorporated herein by reference in its entirety.
  • the principles of the present invention may also be used where noncontiguous, widely separated or multiple simultaneously scanned sectors are desired.
  • Figs. 3a and 3b show top and side views, respectively, of a planar array antenna 10 in accordance with the present invention.
  • the planar array antenna 10 comprises a continuous transverse stub array antenna 11 that is fed edgewise by two scanning line feeds 12. 13 (ferrite line scanners) disposed along opposite sides of the continuous transverse stub array antenna 11.
  • a switching matrix 14 is used to feed an RF signal from an RF port 14a to respective ports 15a- 15d of the scanning line feeds 12, 13.
  • RF energy couples through slots 16 (Fig. 6) in a common wall between parallel-plate regions of the scanning line feeds 12, 13 and the continuous transverse stub array antenna 11.
  • the continuous transverse stub array antenna 11 is designed in a manner similar to the line feeds 12, 13 using bidirectional array excitation synthesis to produce a well-formed beam when it is fed along either side.
  • the switching matrix 14 sequentially feeds each of the four RF ports 15a-15d.
  • the scanning line feeds 12, 13 feed the planar array antenna 11 from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. This effectively produces a single beam that scans over four contiguous scan sectors.
  • a four-way switching matrix 14 directs an RF signal to a selected antenna port 15a-15d.
  • Fig. 4 shows how a single pole, four throw (SP4T) switching matrix 14 may be configured using three switching ferrite circulators 17. Typical W-band performance for a single, narrow-band junction circulator 17 provides for a 0.4 to 0.6 dB insertion loss and 18 to 20 dB isolation. Greater isolation may be obtained by placing additional junction circulators 17 in switch arms of the switching matrix 14 shown in Fig. 4, but this increases the insertion loss accordingly.
  • Figs. 5 and 6 show a suitable arrangement that may be used to package a plurality of continuous transverse stub antennas 11 (subarrays 11) in a very tight lattice.
  • the line feeds 12, 13 cannot be physically located along the edges of the antenna 11 as shown in Fig. 3, and are placed behind the aperture or the antenna 11.
  • Coupling between the line feeds 12, 13 and the antenna 11 is implemented using coupling slots 16 disposed through a common ground plane wall.
  • Two types of coupling slots 16 are illustrated in Fig. 5, which include longitudinal shunts slots 16 alternately offset from the broadwall centerline in the first feed 12. and inclined slots 16 in the second feed 13.
  • 180-degree waveguide bends 18 that connect the feed ports 15a- 15d to the switching matrix 14 extend beyond the outline of the aperture of the continuous transverse stub antenna 11 along a vertical direction.
  • pockets 19 on the back side of the antenna 11 allow the antennas 11 (subarrays 1 1) to be nested, as is shown in Fig. 7 to produce a complete planar array antenna 10.
  • Figs. 8a and 8b show computed forward-fired and backward-fired beam patterns, respectively, for a 77 GHz bidirectional line feed 12, 13 that is 4.49 inches long.
  • a modified Woodson-Lawson synthesis was used to create the line feed 12, 13, with exponential functions replacing conventional uniform functions.
  • the beam patterns although not optimized, meet nominal array requirements of a 2.2 degrees beamwidth at the -3 dB points and sidelobes below 20 dB.
  • the forward- fired beam pattern has a taper loss of 1.06 dB, VSWR of 1.06:1 and 3.6 percent power into the load.
  • the back-fired beam pattern has a taper loss of 1.10 dB, VSWR of 1.04: 1 and 2.9 percent power into a load.
  • a similar bidirectional array excitation synthesis may be used to design the continuous transverse stub array antenna 11.
  • the present invention may be configured to provide a low-cost solution for achieving scan coverage throughout the volume of a cone. This may be done by mounting a one-dimensional scanner on a roll gimbal (i.e., a "lazy Susan"). With this arrangement, the one-dimensional scanner only needs to cover one-half of the apex angle (i.e., from the zero axis of the cone to the slant angle). As the gimbal rotates in an orthogonal plane, the scanning beam will "sweep out" a conical scan volume.
  • the present invention was originally developed to address a specific application where a one-dimensional scanner requires zero to 60 degree coverage. However, other options for wide angle scanning may be provided by the present invention.
  • the present invention may be used to provide scan coverage that is symmetrical with respect to broadside (zero degrees). This is the typical scan coverage of a forward looking automotive antenna, for example.
  • the present scanner may be modified to have four contiguous scan sectors, that scans from zero to ⁇ 12.59° and from ⁇ 12.59° to ⁇ 25.85°, which are desirable for a forward looking automotive antenna.
  • the present invenuon may be used to provide scan coverage that provides an asymmetrical scan about broadside.
  • a shipboard antenna is often tilted upward as much as 20 degrees to accommodate coverage at higher elevation angles as the ship rolls downward.
  • an antenna tilted upward 12.5 degrees may be configured to provide four contiguous scan sectors that cover - 12.59 to +40 85 degrees. If the ship is stabilized to limit roll to 10 degrees maximum, elevation coverage of at least 4-30 degrees may be realized.
  • the four scan sectors provided by the present invention need not be contiguous, but may overlap or be angularly separated. If two scan sectors overlap with beams offset in space by about one-half a beam width, then a scanning difference pattern may be formed by sequentially lobing between the two adjacent beams.
  • An example where separate scan sectors are desirable is a side-looking radar mounted on the underside of an aircraft. Scan coverage might be ⁇ 12.59 degrees to ⁇ 25.85 degrees, with a gap between -12.59 and 412.59 degrees.
  • any of the four scan sectors may be simultaneous scanned, rather than sequentially scanned. However, this requires a different switching matrix than the SP4T switching matrix 14 shown in Fig. 4.
  • the switching matrix 14 is designed to simultaneously switch on one through four beams at any given time.
  • Such a simultaneous switching matrix 14 is conventional and well-known, and may be readily designed by those skilled in the art and will not be described herein. With simultaneous overlapping beams, the scanning difference pattern described above would not require lobing.

Abstract

A planar array antenna (10) having a switching matrix (14) that couples an RF signal to two distributed ferrite scanning line feeds (12, 13) that feed a planar continuous transvers stub array antenna (11). The scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. The antenna has reduced complexity and lower design and production costs. The use of dual ferrite scanning line feeds, the switching matrix, and the continuous transverse stub antenna to obtain wide-angle scanning provides significantly improved performance. The present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter-wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability. The scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, to increase the angular scan coverage of the antenna. The switching matrix is used to sequentially feed each of four RF ports, which effectively produces a single beam that scans over the four contiguous scan sectors.

Description

MICROWAVE ANTENNA HAVING WIDE ANGLE SCANNING CAPABILITY
BACKGROUND
The present invention relates generally to microwave antennas, and more particularly, to a microwave antenna having wide angle scanning capability.
Prior art teaches how a scanning line feed can be fed from its opposite ends to form two beams that are offset in space. Such scanning line feeds are described in articles by Nester, et al. entitled "Bidirectional Series Fed Slot Array", Symp. Digest, IEF.F, Antennas and Propagation Society International Symposium (Stanford, CA), June 1977, pg. 76, or Kinsey entitled "FAST Multibeam Antenna Concept", RADC- TR-85-170, Proc. Phased Arrays 1985 Symposium (Hanscom AFB, MA), Sept. 1985, pp. 33-56.
There is increasing interest in low-cost, one-dimensional electronically scanned antennas for military and commercial applications, such as W-band targeting radars and forward looking radar automotive systems at 77 GHz, for example. Low-cost two- dimensional scanning can be realized by using the aforementioned one-dimensional electronic scan antenna in conjunction with a 360° gimbal in the second axis. Conventional scanning techniques, such as PIN diodes, discrete ferrite phase shifters or transmit/receive (T/R) modules are generally either not available, not producible, or are relatively unaffordable at W-band.
Ferrite phase scanning antennas that radiate into free space are described in the technical literature. Ferrite phase scanning antennas are discussed in articles by Stern, et al. entitled "A mm- Wave Homogeneous Ferrite Phase Scan Antenna." Microwave Journal. Vol. 30, No. 4, Apr. 1987, pp. 101-108, and U. S. Patent No. 4,691,208 entitled "Ferrite Waveguide Scanning Antenna", for example.
A ferrite scanning line feed is a device that is similar to the previously discussed scanning line feed, and has the same limitations in scan range. The distinction is that the line feed is specifically designed to radiate into a parallei-plate region of a planar array antenna, which may be either air or dielectrically filled. Further, the scanning line feed is designed using bidirectional array excitation synthesis to be fed from either end, producing two well-formed beams offset in space. A major disadvantage of the prior art is the limited scan coverage that can be realized with ferrite phase scanned antennas at high millimeter-wave frequencies, typically on the order of from 40 GHz and above. It would therefore be an advance in the an to have a planar array antenna that does not require a multitude of line feeds that are scanned with discrete phase shifters, such as those described in the Kinsey article, for example. It would also be an advantage to have a planar array antenna that has reduced complexity with much lower design and production costs. Accordingly, it is an objective of the present invention to provide for a microwave antenna having wide angle scanning capability.
SUMMARY OF THE INVENTION
The present invention provides for a planar array antenna that uses two distributed ferrite scanning line feeds to feed a planar array antenna, such as a continuous transverse stub array. The scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. The present invention does not require a multitude of line feeds that are scanned with discrete phase shifters such as is described in the Kinsey article. This reduction in complexity, combined with a 360° gimbal in the second axis, results in lower design and production costs for the antenna. The use of dual ferrite scanning line feeds, a switching matrix, and a planar array antenna to obtain wide-angle scanning significantly improves the performance of continuous transverse stub (CTS) antennas and systems.
The present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter- wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability. The scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, thereby increasing the angular scan coverage of the antenna at least fourfold. The switching matrix is used to sequentially feed each of four RF ports to effectively produce a single beam that scans over the four contiguous scan sectors.
BRIEF DESCRIPTION OF THE DRAWINGS The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like structural elements, and in which:
Fig. 1 illustrates the computed scan coverage versus frequency for a ferrite line scanner with 4πMs = 5,000 Gauss;
Fig. 2 illustrates how contiguous scan sectors covering over 60° are produced by switching between four RF ports;
Figs. 3a and 3b illustrate a planar array antenna in accordance with the present invention edge-fed by two scanning line feeds; Fig. 4 illustrates a switching matrix having three switching ferrite circulators;
Figs. 5 and 6 illustrate how scanning line feeds couple through a ground plane into the parallel-plate region of a continuous transverse stub array antenna;
Fig. 7 illustrates a planar array antenna comprised of continuous transverse stub subarrays nested in a triangular lattice; and Figs. 8a and 8b show computed forward-fired and backward-fired beam patterns, respectively, of a 77 GHz line feed designed using a modified Woodward- Lawson synthesis.
DETAILED DESCRIPTION Referring to the drawing figures, Fig. 1 shows a graph illustrating the computed scan coverage versus frequency that is achievable for a typical conventional ferrite line scanner using state-of-the-art ferrite materials with the maximum saturation magnetization (4πMs) available, which is approximately 5,000 Gauss. The graph of Fig. 1 is based on measured data of differential phase shift per inch at several millimeter-wave frequencies. Approximately 625 inch was obtained at 94 GHz. This produces only about 12.6 degrees of scan coverage, while as much as 60 degrees may be required for certain antenna applications.
Fig. 2 shows four contiguous scan sectors that are produced by the present invention that cover 0° to +12.6°, +12.6° to +25.8°, +25.8° to 440.8°, and 440.8° to +60.7°, respectively. These numbers are derived from the expression: θ„ = Sin-' (nλΔφ/360), where: θ n m ma,xr is the maximum scan ang "—le for a g>iven scan sector, n is the scan sector ( "• 1 through 4 for this example), λ is the wavelength in air in inches (0.1256 inches for 94 GHz); and ΔΦ is the differential phase shift in degrees per inch (625).
The present invention switches between multiple contiguous scan sectors as shown in Fig. 2 in order to increase the total angular scan coverage of a scanning antenna 10 (shown in Figs. 3a and 3b), and is believed to be unique as applied to a planar array scanning antenna 10, such as a continuous transverse stub antenna 11 developed by the assignee of the present invention. The continuous transverse stub antenna 11 is described in U. S. Patent No. 5,266,961 assigned to the assignee of the present invention and the disclosure thereof is incorporated herein by reference in its entirety. The principles of the present invention may also be used where noncontiguous, widely separated or multiple simultaneously scanned sectors are desired.
Figs. 3a and 3b show top and side views, respectively, of a planar array antenna 10 in accordance with the present invention. The planar array antenna 10 comprises a continuous transverse stub array antenna 11 that is fed edgewise by two scanning line feeds 12. 13 (ferrite line scanners) disposed along opposite sides of the continuous transverse stub array antenna 11. A switching matrix 14 is used to feed an RF signal from an RF port 14a to respective ports 15a- 15d of the scanning line feeds 12, 13. RF energy couples through slots 16 (Fig. 6) in a common wall between parallel-plate regions of the scanning line feeds 12, 13 and the continuous transverse stub array antenna 11. The continuous transverse stub array antenna 11 is designed in a manner similar to the line feeds 12, 13 using bidirectional array excitation synthesis to produce a well-formed beam when it is fed along either side. The switching matrix 14 sequentially feeds each of the four RF ports 15a-15d. The scanning line feeds 12, 13 feed the planar array antenna 11 from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. This effectively produces a single beam that scans over four contiguous scan sectors.
A four-way switching matrix 14 directs an RF signal to a selected antenna port 15a-15d. Fig. 4 shows how a single pole, four throw (SP4T) switching matrix 14 may be configured using three switching ferrite circulators 17. Typical W-band performance for a single, narrow-band junction circulator 17 provides for a 0.4 to 0.6 dB insertion loss and 18 to 20 dB isolation. Greater isolation may be obtained by placing additional junction circulators 17 in switch arms of the switching matrix 14 shown in Fig. 4, but this increases the insertion loss accordingly. Figs. 5 and 6 show a suitable arrangement that may be used to package a plurality of continuous transverse stub antennas 11 (subarrays 11) in a very tight lattice. Because the apertures of the continuous transverse stub antennas 11 are so close to one another, the line feeds 12, 13 cannot be physically located along the edges of the antenna 11 as shown in Fig. 3, and are placed behind the aperture or the antenna 11. Coupling between the line feeds 12, 13 and the antenna 11 is implemented using coupling slots 16 disposed through a common ground plane wall. Two types of coupling slots 16 are illustrated in Fig. 5, which include longitudinal shunts slots 16 alternately offset from the broadwall centerline in the first feed 12. and inclined slots 16 in the second feed 13. 180-degree waveguide bends 18 that connect the feed ports 15a- 15d to the switching matrix 14 extend beyond the outline of the aperture of the continuous transverse stub antenna 11 along a vertical direction. However, pockets 19 on the back side of the antenna 11 (shown in Fig. 6) allow the antennas 11 (subarrays 1 1) to be nested, as is shown in Fig. 7 to produce a complete planar array antenna 10.
Figs. 8a and 8b show computed forward-fired and backward-fired beam patterns, respectively, for a 77 GHz bidirectional line feed 12, 13 that is 4.49 inches long. A modified Woodson-Lawson synthesis was used to create the line feed 12, 13, with exponential functions replacing conventional uniform functions. The beam patterns, although not optimized, meet nominal array requirements of a 2.2 degrees beamwidth at the -3 dB points and sidelobes below 20 dB. The forward- fired beam pattern has a taper loss of 1.06 dB, VSWR of 1.06:1 and 3.6 percent power into the load. The back-fired beam pattern has a taper loss of 1.10 dB, VSWR of 1.04: 1 and 2.9 percent power into a load. As stated previously, a similar bidirectional array excitation synthesis may be used to design the continuous transverse stub array antenna 11.
The present invention may be configured to provide a low-cost solution for achieving scan coverage throughout the volume of a cone. This may be done by mounting a one-dimensional scanner on a roll gimbal (i.e., a "lazy Susan"). With this arrangement, the one-dimensional scanner only needs to cover one-half of the apex angle (i.e., from the zero axis of the cone to the slant angle). As the gimbal rotates in an orthogonal plane, the scanning beam will "sweep out" a conical scan volume.
The present invention was originally developed to address a specific application where a one-dimensional scanner requires zero to 60 degree coverage. However, other options for wide angle scanning may be provided by the present invention.
For example, the present invention may be used to provide scan coverage that is symmetrical with respect to broadside (zero degrees). This is the typical scan coverage of a forward looking automotive antenna, for example. The present scanner may be modified to have four contiguous scan sectors, that scans from zero to ±12.59° and from ±12.59° to ±25.85°, which are desirable for a forward looking automotive antenna. The present invenuon may be used to provide scan coverage that provides an asymmetrical scan about broadside. A shipboard antenna is often tilted upward as much as 20 degrees to accommodate coverage at higher elevation angles as the ship rolls downward. For example, an antenna tilted upward 12.5 degrees may be configured to provide four contiguous scan sectors that cover - 12.59 to +40 85 degrees. If the ship is stabilized to limit roll to 10 degrees maximum, elevation coverage of at least 4-30 degrees may be realized.
The four scan sectors provided by the present invention need not be contiguous, but may overlap or be angularly separated. If two scan sectors overlap with beams offset in space by about one-half a beam width, then a scanning difference pattern may be formed by sequentially lobing between the two adjacent beams. An example where separate scan sectors are desirable is a side-looking radar mounted on the underside of an aircraft. Scan coverage might be ±12.59 degrees to ±25.85 degrees, with a gap between -12.59 and 412.59 degrees. Furthermore, any of the four scan sectors may be simultaneous scanned, rather than sequentially scanned. However, this requires a different switching matrix than the SP4T switching matrix 14 shown in Fig. 4. In a simultaneous beam scanning application, the switching matrix 14 is designed to simultaneously switch on one through four beams at any given time. Such a simultaneous switching matrix 14 is conventional and well-known, and may be readily designed by those skilled in the art and will not be described herein. With simultaneous overlapping beams, the scanning difference pattern described above would not require lobing.
Thus, an improved planar array microwave antenna having wide angle scanning capability has been disclosed. It is to be understood that the described embodiment is merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.

Claims

CLAIMSWhat is claimed is:
1. A planar array microwave antenna (10) characterized by: a continuous transverse stub array antenna (11); first and second scanning line feeds (12, 13) disposed along opposite edges of the continuous transverse stub array antenna that comprise first and second RF ports (15a, 15b), (15c, 15d), respectively, that feed an RF input signal to the continuous transverse stub array antenna; and a switching matrix (14) coupled between an RF input port (14a) of the antenna and respective ports of the scanning line feeds; and wherein the scanning line feeds couple RF energy to the planar array antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors.
2. The antenna (10) of Claim 1 wherein four beams effectively produce a single beam that scans over four contiguous scan sectors.
3. The antenna (10) of Claim 1 wherein RF energy is coupled through slots (16) in a common wall between parallel-plate regions of the scanning line feeds (12, 13) and the continuous transverse stub array antenna (11).
4. The antenna (10) of Claim 1 wherein the switching matrix (14) is characterized by a four-way switching matrix (14).
5. The antenna (10) of Claim 1 wherein the four-way switching matrix (14) is characterized by three switching ferrite circulators (17).
6. The antenna (10) of Claim 1 wherein scan coverage is symmetrical with respect to broadside.
7. The antenna (10) of Claim 1 wherein scan coverage is asymmetrical with respect to broadside.
8. The antenna (10) of Claim 1 wherein the four scan sectors overlap.
9. The antenna (10) of Claim 1 wherein the four scan sectors are angularly separated from each other.
PCT/US1998/016216 1997-08-06 1998-08-05 Microwave antenna having wide angle scanning capability WO1999008338A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
GB9907696A GB2334383B (en) 1997-08-06 1998-08-05 Microwave antenna having wide angle scanning capability
ES009950016A ES2152906B1 (en) 1997-08-06 1998-08-05 MICROWAVE ANTENNA WITH LARGE ANGLE EXPLORATION CAPACITY.
IL12923398A IL129233A (en) 1997-08-06 1998-08-05 Microwave antenna having wide angle scanning capability
DE19881296T DE19881296B4 (en) 1997-08-06 1998-08-05 Microwave antenna array
JP51225099A JP3754091B2 (en) 1997-08-06 1998-08-05 Microwave antenna with wide-angle scanning capability

Applications Claiming Priority (2)

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US08/906,699 1997-08-06
US08/906,699 US5905472A (en) 1997-08-06 1997-08-06 Microwave antenna having wide angle scanning capability

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JP (1) JP3754091B2 (en)
DE (1) DE19881296B4 (en)
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GB (1) GB2334383B (en)
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KR100767543B1 (en) * 2000-08-16 2007-10-17 레이던 컴퍼니 Switched beam antenna architecture
EP1314221B1 (en) 2000-08-31 2004-11-10 Raytheon Company Mechanically steerable array antenna
WO2002021156A2 (en) * 2000-09-08 2002-03-14 Raytheon Company Path prediction system and method
US6653985B2 (en) 2000-09-15 2003-11-25 Raytheon Company Microelectromechanical phased array antenna
US6708100B2 (en) * 2001-03-14 2004-03-16 Raytheon Company Safe distance algorithm for adaptive cruise control
US6421021B1 (en) 2001-04-17 2002-07-16 Raytheon Company Active array lens antenna using CTS space feed for reduced antenna depth
US6995730B2 (en) * 2001-08-16 2006-02-07 Raytheon Company Antenna configurations for reduced radar complexity
US6611227B1 (en) 2002-08-08 2003-08-26 Raytheon Company Automotive side object detection sensor blockage detection system and related techniques
US7079082B2 (en) * 2004-03-31 2006-07-18 University Of Hawaii Coplanar waveguide continuous transverse stub (CPW-CTS) antenna for wireless communications
US7061443B2 (en) * 2004-04-01 2006-06-13 Raytheon Company MMW electronically scanned antenna
JP2006033034A (en) 2004-07-12 2006-02-02 Japan Aviation Electronics Industry Ltd Electromagnetic wave transmitting/receiving device
US8487832B2 (en) 2008-03-12 2013-07-16 The Boeing Company Steering radio frequency beams using negative index metamaterial lenses
US8130171B2 (en) * 2008-03-12 2012-03-06 The Boeing Company Lens for scanning angle enhancement of phased array antennas
US8493281B2 (en) * 2008-03-12 2013-07-23 The Boeing Company Lens for scanning angle enhancement of phased array antennas
EP2260322A1 (en) * 2008-03-31 2010-12-15 Valeo Radar Systems, Inc. Automotive radar sensor blockage detection apparatus and method
KR101182425B1 (en) * 2008-12-22 2012-09-12 한국전자통신연구원 Slot atenna with stubs
EP2202535A1 (en) * 2008-12-23 2010-06-30 Sony Corporation Radiometric electrical line sensor in combination with mechanical rotating mirror for creating 2D image
US8493276B2 (en) * 2009-11-19 2013-07-23 The Boeing Company Metamaterial band stop filter for waveguides
US8395552B2 (en) * 2010-11-23 2013-03-12 Metamagnetics, Inc. Antenna module having reduced size, high gain, and increased power efficiency
KR101903212B1 (en) 2011-05-09 2018-10-01 메타마그네틱스, 인코포레이티드. Magnetic grain boundary engineered ferrite core materials
US8750792B2 (en) 2012-07-26 2014-06-10 Remec Broadband Wireless, Llc Transmitter for point-to-point radio system
US11474147B2 (en) * 2017-12-19 2022-10-18 Boston Semi Equipment Llc Kit-less pick and place handler system for thermal testing
US10727591B2 (en) * 2018-08-06 2020-07-28 Honeywell International Inc. Apparatuses and methods for a planar waveguide antenna

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3078463A (en) * 1958-12-01 1963-02-19 Csf Parallel plate waveguide with slotted array and multiple feeds
US3471857A (en) * 1967-05-24 1969-10-07 Singer General Precision Planar array antenna arrangements
US3508275A (en) * 1968-03-12 1970-04-21 Singer General Precision Doppler array with interleaved transmitting and receiving slotted waveguides
EP0536522A2 (en) * 1991-08-29 1993-04-14 Hughes Aircraft Company Continuous traverse stub element devices and method for making same
US5264852A (en) * 1991-01-22 1993-11-23 Alcatel Espace Satellite equipment for measuring the backscatter coefficient of the sea

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2943325A (en) * 1957-03-20 1960-06-28 Rotman Walter Electro-mechanically scannable trough waveguide transmission lines and antennas
US3205493A (en) * 1963-05-21 1965-09-07 North American Aviation Inc Microwave switch
US3768041A (en) * 1972-04-17 1973-10-23 North American Rockwell Waveguide switch
US4691208A (en) * 1984-07-02 1987-09-01 The United States Of America As Represented By The Secretary Of The Army Ferrite waveguide scanning antenna
CA1234903A (en) * 1987-07-16 1988-04-05 Anthony R. Raab Electronically scanned radar system
US5626961A (en) * 1995-06-30 1997-05-06 E. I. Du Pont De Nemours And Company Polyester filaments and tows

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3078463A (en) * 1958-12-01 1963-02-19 Csf Parallel plate waveguide with slotted array and multiple feeds
US3471857A (en) * 1967-05-24 1969-10-07 Singer General Precision Planar array antenna arrangements
US3508275A (en) * 1968-03-12 1970-04-21 Singer General Precision Doppler array with interleaved transmitting and receiving slotted waveguides
US5264852A (en) * 1991-01-22 1993-11-23 Alcatel Espace Satellite equipment for measuring the backscatter coefficient of the sea
EP0536522A2 (en) * 1991-08-29 1993-04-14 Hughes Aircraft Company Continuous traverse stub element devices and method for making same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113851841A (en) * 2021-09-08 2021-12-28 西安电子科技大学 Variable inclination CTS antenna is controlled mutually to high power

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DE19881296B4 (en) 2005-10-06
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IL129233A0 (en) 2000-02-17
GB2334383B (en) 2002-07-17
ES2152906A1 (en) 2001-02-01
IL129233A (en) 2002-07-25
JP3754091B2 (en) 2006-03-08
DE19881296T1 (en) 1999-10-14
GB9907696D0 (en) 1999-05-26
US5905472A (en) 1999-05-18
JP2000505992A (en) 2000-05-16

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