Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P3/00—Waveguides; Transmission lines of the waveguide type
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/0087—Apparatus or processes specially adapted for manufacturing antenna arrays
• • 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
• • 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
  • H01Q21/0006—Particular feeding systems
  • H01Q21/0031—Parallel-plate fed arrays; Lens-fed arrays
• • 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

• CTS arrays are disclosed, for example, in U.S. Patents 5,926,077; 5,995,055; and 6,075,494.
• CTS arrays can be implemented as true-time-delay (TTDCTS) apertures employing parallel plate feeds.
• TTDCTS true-time-delay
• rails of varying shapes that are fabricated and assembled together in order to realize the aperture/parallel plate feed assembly.
• phased arrays also can perform these functions, but include a fully populated lattice of discrete phase-shifters or transmit/receive elements each requiring their own phase and/or power-control lines. The recurring (component, assembly, and test) costs, prime-power, and cooling requirements associated with such electronically controlled phased-arrays can be prohibitive in many applications.
• a true-time-delay feed network for a continuous transverse stub antenna array includes a plurality of feed levels, each comprising one or more rails, the feed levels arranged in a spaced, parallel configuration. An open parallel plate region is defined between adjacent ones of the feed levels.
• the rails of the plurality of feed levels are arranged to form a power divider network unencumbered with septums or wall portions protruding into the open region.
• FIG. 1 is an isometric view of an exemplary embodiment of a parallel plate feed and antenna aperture assembly, with a continuous transverse stub (CTS) radiating aperture surface.
• CTS transverse stub
• FIG. 2 is a simplified cross-sectional view, taken along line 2-2 of FIG. 1.
• FIG. 3 is an exploded view of levels of the parallel plate feed and antenna aperture assembly of FIGS. 1-2.
• FIG. 4 is a bottom isometric view of the assembly of FIGS. 1-3, showing a feed surface.
• FIG. 5 is an exemplary virtual E-bend/Tee schematic diagram.
• FIGS. 1-5 illustrate an exemplary embodiment of a TTDCTS parallel plate feed and antenna aperture assembly 10 in accordance with the invention.
• the assembly 10 comprises a plurality of levels of rails, each level held in a spaced relationship with respect to adjacent rails.
• the rails at the various levels of the exemplary embodiment of the assembly need not have physical contact to form the hard shorts used in a corporate feed.
• features on the rails at any one level of the assembly are identical and periodic, which can reduce tooling and manufacturing cost.
• An aperture level 20 comprises a plurality of spaced rails 22A-22I, which define radiating stubs 24A-24H.
• Interior rails 22B-22H are identical.
• End or exterior rails 22A and 221 are mirror images of each other, and are truncated versions of the interior rails.
• the first parallel plate feed level 30 comprises a plurality of spaced rails 32A-32E, spaced apart such that adjacent edges of the rails define slots 34A-34D.
• Interior rails 32B-32D are identical.
• End or exterior rails 32A and 32E are truncated versions of the interior rails.
• the rails are formed with respective pairs of inductive wells or grooves, e.g. grooves 32D-1, 32D-2 formed in rail 32-D, which are discussed more fully below.
• the second parallel plate feed level 40 comprises a plurality of spaced rails 42A-42C, spaced apart such that adjacent edges of the rails define slots44A, 44B.
• the end rails 42A, 42C are truncated versions of the interior rail 42B.
• the rails have pairs of wells formed therein as well.
• the ' third parallel plate feed level 50 comprises two rails 52A, 52B, spaced apart such that adjacent edges of the rails form a slot 54A.
• Each rail has a pair of wells formed therein as well.
• the rails of each level can be fabricated as a single unit, or assembled together to form a single unit, reducing the number of parts.
• the rails have electrically conductive surfaces, and can be fabricated from a metal, e.g. aluminum, by machining, extrusion, or other processes.
• the rails can be fabricated from a plastic material, e.g. by molding or extrusion, and plated with a conductive layer.
• the levels 20, 30, 50 and 50 are assembled together in a spaced relationship, as illustrated in FIG. 2, forming open parallel plate regions 28, 38, 48 between respective adjacent levels.
• the open regions are unencumbered by hard shorts or bends or protruding septums of power dividers utilized in conventional waveguide or parallel plate feeds.
• RF energy is launched into the slot 54A, e.g. by a line source, and divides into two components which propagate in opposite directions in the parallel plate region 48, thus forming a 1:2 power divider.
• Energy propagating in the region 48 enters slots 44A, 44B in level 40, and divides into respective components which propagate in the parallel plate region 38, thus forming two 1:2 power dividers.
• the input energy has been divided into four components .
• the energy propagating in region 38 enters slots 34A-34D in level 30, separating into respective pairs of energy components which propagate in region 28 adjacent the aperture level 20.
• the input energy has been divided into eight components in region 28, one component for each transverse s ' tub24A-24H.
• the respective energy components radiate from the respective stubs.
• the path lengths from the slot 54A to the respective stubs are equal in length, so that the time delay is equal for each path, and the signal components radiated from each slot will be in phase.
• the received signal components at each stub will be combined in phase to provide a single combined signal component at slot 54A.
• FIG. 3 is an exploded view of an exemplary embodiment of a TTDCTS aperture parallel plate assembly, showing the levels 20, 30, 40, 50, which when stacked in spaced relation form the assembly 10 of FIG. 4.
• Each level includes a peripheral frame to hold the respective rails of that level in place as a single unit.
• frame 56 holds the rail 52A of level 50
• frame 46 holds the rails 42A-42C of level 40
• frame 36 holds the rails 32A-32E of level
• frame 26 holds the rails 22A-22I of the aperture level 20.
• the individual rails can be assembled to the frame using various techniques, including fasteners, brazing, welding, adhesives or even by a pressure fit into mounting areas of the frame.
• the frames can have a thickness which provides the desired spacing between adjacent levels when the frames are stacked together.
• FIG. 4 is an isometric view showing the assembly 10 with the levels stacked together.
• the ' assembly 10 makes use of "virtual" shorts that replace a perfect electrical conductor (“PEC") short wall in the path of propagating waves inside the parallel-plate or rectangular waveguide structures, typically arranged at a 45 degree angle to direct energy from a parallel plate region into a slot communicating with a next level.
• the virtual short is matched by inductive wells or grooves formed in the parallel plate structure where the propagating wave is confined.
• the depth, width and the number of wells replacing the PEC short wall are dependent on bandwidth and the separation distance between the walls.
• the assembly 10 also makes use of septum- less TEE E-plane power dividers, that do not employ protruding septums in front of the input arm of the TEE. Instead, the protruding septum and its function (matching) can replaced by one or more inductive wells or grooves, e.g. a pair of wells formed in the two co-linear arms of the TEE, if desirable for a particular application.
• the dimensions of the wells and their distances to the input arm determine the bandwidth and matching properties of the tee.
• FIG. 5 is a simplified schematic illustrating a septum-less E-plane TEE power divider and virtual short.
• Input RF energy indicated by arrow 110 enters the TEE power divider 100 through an input arm 102, and is divided between the two co-linear side arms 104, 106.
• the divided energy components are indicated by arrows 112, 114.
• pairs of inductive wells are formed in the parallel-plate structure opposite the input arm 102.
• a pair of wells 120, 122 are formed in the wall 104A of side arm 104
• a pair of wells 124, 126 are formed in the wall 106A of side arm 106.
• the spacing of the pairs of wells from the input arm, and the well dimensions, are selected for a given implementation in dependence on bandwidth and the matching properties for that application. It is noted that there is no protruding septum structure into the space S at the TEE junction.
• the incorporation of depth and width adjusted wells or troughs in the co-linear side arms creates matching susceptances for the remaining ports of the same TEE structure.
• maintaining an integral half-wavelength spacing between the wells and input arm provides dual-band frequency capability. For example, a centerline between wells 120, 122 is spaced a distance from the center of the input arm 102 approximately equal to an integral multiple of one half wavelength at a center frequency of each operating band.
• An exemplary dual band embodiment supports operation at a first band centered at 20.7 Ghz, and at a second band centered at 44.5 Ghz, by way of example, i.e. where the center frequency of the second band is approximately double that of the first band.
• the septum-less TEE power divider as employed in the feed network of the TTDCTS array may not employ matching wells formed in each side arm port.
• the exemplary embodiment of FIG. 2, for example is illustrated without side arm matching wells for the septum-less TEE power dividers.
• a tuning well is positioned at a wall opposite the input port, e.g. well 57.
• a virtual short 130 is also illustrated in FIG. 5.
• the energy in side arm channel 104 is to be directed into channel 140, as indicated by arrow 144.
• the energy in side arm channel 106 is to be diverted into channel 142, as indicated by arrow 146.
• circuit 130 is a matching network for one virtual short, and comprises a plurality of spaced inductive wells or grooves 132A-132C formed in a wall of the side arm channel 104.
• Circuit 136 is a matching network for a second virtual short to divert energy into channell42, and comprises a plurality of spaced inductive wells or grooves 138A-138C formed in a wall of the side arm channel 106.
• the matching network for the virtual short introduces a very high susceptance that eliminates the need for a physical short, i.e. an electrically conductive wall.
• the number of wells and the well depth and width are parameters which can be varied to optimize the matching for the virtual shorts, taking into account all of the feed levels at once.
• septum-less TEE power dividers and virtual shorts are employed in the assembly 10.
• This input energy is divided by a septum-less TEE 56 defined by facing surfaces of the rails 52A, 52B and 42A-42C and open channel 48, and is directed in opposite directions within open channel 48, to be directed into open slots 44A, 44B in the second level 40.
• Virtual shorts 58A, 58B comprising inductive wells are formed in the top surfaces of the rails. RF energy does not propagate along space 48 past the virtual shorts 58A-58B.
• Slots 44A, 44B comprise input arms for septum-less TEE power dividers 46A, 46B, to divide the RF energy entering these power dividers into RF energy components conducted into open channel 38.
• the energy components from divider 46A enter slots 34A, 34B in feed level 30, and the energy components from divider 46B enter slots 34C, 34D in feed level 30.
• a third level of power dividers 56A, 56B, 56C, 56D in turn divides the power from the second level of dividers 46A, 4 ⁇ B into eight RF energy components which are directed into the radiating stubs 24A-24H.
• Each of these power dividers of the first, second and third levels of power dividers in this embodiment are septum-less power dividers, i.e. without a septum element protruding into the open channel between levels.
• These power dividers further include tuning wells formed on the wall opposite the input arm or channel to improve impedance matching.
• TEE divider 56 includes a well 57.
• TEEs 46A, 46B respectively include wells 47A, 47B.
• TEEs 56A-56D include wells 57A-57D, respectively. Virtual shorts are employed instead of hard shorts extending into the open channels.
• virtual shorts 58A, 58B each comprising a pair of inductive wells formed in the surface of respective rails 52A, 52B, prevent energy entering from input port 57A from passing beyond the shorts.
• virtual shorts 48A, 48B are positioned for TEE 46A
• virtual shorts 48C, 48D are positioned for TEE 46B.
• virtual shorts 38A, 38B are positioned for TEE 56A
• virtual shorts 38C, 38D are positioned for TEE 56B
• virtual shorts 38E, 38F are positioned for TEE 56C
• virtual shorts 38G, 38H are positioned for TEE 56D.
• the antenna aperture and parallel plate feed assembly described above is capable of reciprocal operation, i.e. for operation on receive as well as transmit.
• slot 54A is described above in terms of an input port for the assembly, the slot functions as an output port when the assembly is operated on receive.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)
• Waveguide Aerials (AREA)
• Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
• Apparatus For Radiation Diagnosis (AREA)
• Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
• Details Of Aerials (AREA)
• Ultra Sonic Daignosis Equipment (AREA)
• Measurement Of Radiation (AREA)

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Citations (4)

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• 2005
  • 2005-03-08 US US11/075,106 patent/US7432871B2/en not_active Expired - Fee Related
• 2006
  • 2006-02-15 WO PCT/US2006/005222 patent/WO2006096290A1/en not_active Ceased
  • 2006-02-15 AT AT06720746T patent/ATE418166T1/de not_active IP Right Cessation
  • 2006-02-15 KR KR1020077020446A patent/KR100894958B1/ko not_active Expired - Fee Related
  • 2006-02-15 DE DE602006004315T patent/DE602006004315D1/de active Active
  • 2006-02-15 EP EP06720746A patent/EP1856769B1/en not_active Not-in-force
  • 2006-02-15 CA CA2600627A patent/CA2600627C/en not_active Expired - Fee Related
  • 2006-02-15 JP JP2008500718A patent/JP4856164B2/ja not_active Expired - Fee Related
  • 2006-02-15 DK DK06720746T patent/DK1856769T3/da active
  • 2006-03-07 TW TW095107721A patent/TWI330426B/zh not_active IP Right Cessation
• 2007
  • 2007-10-04 NO NO20075024A patent/NO20075024L/no not_active Application Discontinuation

Patent Citations (4)

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