The present invention relates to a triplate line-to-waveguide transducer with a structure for millimeter wavelengths.
Recent planer antennas for microwaves or millimeter wavelengths have an electric feed-through system configured as a triplate transmission line to provide a highly efficient characteristic, as a prevailing trend. Planer antennas of such a triplate line feed-through system are adapted to synthesize power fed from antenna elements through the triplate transmission line, and in most cases they have, at an interconnect between a final end that outputs synthesized power and an RF signal processing circuit, a triplate line-to-waveguide transducer implementing easy assembly and high connection integrity.
a) and 1(b) illustrate, as a part of the background, a configuration of such a triplate line-to-waveguide transducer (refer e.g. to Japanese Utility Model Registration Application Laid-Open Publication No. 06-070305 and Japanese Patent Application Laid-Open Publication No. 2004-215050). In the conventional configuration, in order for the conversion for waveguide system to be facilitated with a small loss, there was a triplate transmission line made up by: a film substrate 4 {
Moreover, for connection of such the circuit system to an input portion of a waveguide 6 {
As illustrated in
In the conventional configuration of triplate line-to-waveguide transducer illustrated in
It is an object of the present invention to provide a triplate line-to-waveguide transducer allowing for fabrication and high connection integrity, at a low cost, with a minimized lower limit of resonance frequency relative to the conventional configuration, without detriment to the low-loss characteristic over a wide bandwidth in the past.
According to an aspect of the present invention, a triplate line-to-waveguide transducer includes a transducer portion configured with and between a waveguide and a triplate transmission line comprised of a film substrate formed with a strip line conductor and laminated over a surface of a ground conductor, with a dielectric substrate in between, and an upper ground conductor laminated over a surface of the film substrate, with another dielectric substrate in between, and the triplate line-to-waveguide transducer comprises a through hole provided through an area on the ground conductor for connection with the waveguide, with dimensions substantially equal to cavity dimensions of the waveguide, a metallic spacer provided as a holding element for the film substrate, with an even thickness to the dielectric substrate, and cooperating with another metallic spacer having substantially equal dimensions to the metallic spacer, to sandwich the film substrate in between, the upper ground conductor being arranged on the other metallic spacer, a quadrate resonant patch pattern formed at an end of the strip line conductor formed to the film substrate, on an area corresponding to a transducer end of the waveguide, and a combination of the quadrate resonant patch pattern and the waveguide arranged for the quadrate resonant patch pattern to have a center position thereof coincident with a center position of the cavity dimensions of the waveguide.
According to another aspect of the present invention, in the triplate line-to-waveguide transducer, the quadrate resonant patch pattern has a dimension thereof in a direction of line connection set up as a free space wavelength λ0 of desirable frequency times approximately 0.32, and a dimension thereof in a direction perpendicular to the direction of line connection set up as the free space wavelength λ0 of desirable frequency times approximately 0.38.
According to another aspect of the present invention, in the triplate line-to-waveguide transducer, those dimensions of cavity walls of the metallic spacers are set up as a free space wavelength λ0 of desirable frequency times approximately 0.59.
According to the present invention, a triplate line-to-waveguide transducer is made up by component members such as a ground conductor, an upper ground conductor, and metallic spacers that can be fabricated at a low cost by a punching, such as of a metallic plate with a desirable thickness, allowing for facile fabrication and high connection integrity, at a low cost, with a minimized lower limit of resonance frequency relative to a conventional configuration, without detriment to a low-loss characteristic over a wide bandwidth in the past.
a) is a plan view of a conventional example, and
a) is a plan view of an embodiment of the present invention, and
a) to (c) are plan views of parts according to embodiment examples of the present invention.
There will be described into details an embodiment of triplate line-to-waveguide transducer according to the present invention, with reference to the drawings.
According to an aspect of the present invention, as illustrated in
According to another aspect of the present invention, as illustrated in
According to another aspect of the present invention, as illustrated in
According to the present invention, a triplate line-to-waveguide transducer is made up by component members such as a ground conductor 1, an upper ground conductor 5, and metallic spacers 7a and 7b that can be fabricated at a low cost by a punching, such as of a metallic plate with a desirable thickness, allowing for facile fabrication and high connection integrity, at a low cost, with a minimized lower limit of resonance frequency relative to a conventional configuration, without detriment to a low-loss characteristic over a wide bandwidth in the past.
a) and 2(b) illustrate the triplate line-to-waveguide transducer, which includes a triplate transmission line that is made up, in order for the conversion for waveguide system to be facilitated with a small loss, by: a film substrate 4 {
Moreover, for connection of the circuit system to an input portion of a waveguide 6 {
b) illustrates metallic spacers 7a and 7b as parts of the triplate line-to-waveguide transducer shown in
In this invention, as illustrated in
The component parts are to be assembled with an established coincidence among a center position of the quadrate resonant patch pattern 8, a center position of cavity dimensions of the waveguide 6, a center position of the through hole of ground conductor 1, and center positions of cavity walls of dimensions E1 by E2 (in
In this invention, preferably, the quadrate, resonant patch pattern 8 should have (as illustrated in
The dimension L1, set as the free space wavelength λ0 of desirable frequency times approximately 0.32, comes near the cavity dimension ‘a’ of the waveguide times approximately 0.98, enabling a smooth conversion of different modes of electric and magnetic waves. Preferable in that respect is the free space wavelength λ0 times a factor within a range of 0.30 to 0.34. The dimension L2, set as the free space wavelength λ0 of desirable frequency times approximately 0.38, renders an extended bandwidth available as a bandwidth that allows for a secured return loss. Preferable in this respect is the free space wavelength λ0 times a factor within a range of 0.32 to 0.4.
In this invention, preferably, the metallic spacers 7a and 7b should have dimensions E1 and E2 of cavity walls thereof in
The film substrate 4 employs a film as a substrate. For example, the substrate may be a flexible substrate with a metal foil such as a copper foil glued thereon. Unnecessary copper foil (metal foil) segments may be removed by etching to form a set of radiation elements with strip conductor lines for their connection. The film substrate may be configured as a copper-glued planer lamination that has a copper foil glued on a thin resin plate in the form of a resin-impregnated glass cloth. The film may be a film of polyethylene, polypropylene, polytetrafluoroethylene, fluorinated ethylene propylene copolymer, ethylene tetrafluoroethylene copolymer, polyamide, polyimide, polyamide-imide, polyarylate, thermoplastic polyimide, polyetherimide, polyether ether ketone, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polysulfone, polyphenylene ether, polyphenylene sulfide, polymethylpentene, or the like. There may be an adhesive agent used for adhesion between film and metal foil. For heat-resistance, dielectric property, and general versatility, preferable is a flexible substrate in the form of a polyimide film with a laminated copper foil. Fluorinated films are preferable for use in view of dielectric characteristics.
For the ground conductor 1 as well as the upper ground conductor 5, there may be use of any metallic plate or metal plated plastic plate as available, while aluminum plates are preferable from viewpoints of light weight and possible low-cost fabrication. They may be configured as a flexible substrate that has a copper foil glued on a film as a substrate, or as a copper-glued planer lamination that has a copper foil glued on a thin resin plate in the form of a resin-impregnated glass cloth.
The waveguide 6, as well as the through hole provided through the ground conductor 1 with dimensions substantially equal to the cavity dimensions, may preferably have a quadrate shape. This may well be an elliptic shape capable of an equivalent transmission of frequencies with respect to the quadrate shape. For the dielectric substrates 2a and 2b, there may well be use of foam or the like that has a small relative permittivity to the air. The foam may be polyolefin foam such as polyethylene or polypropylene, polystyrene foam, polyurethane foam, polysilicon foam, or rubber foam, while polyolefin foam is preferable as having a smaller relative permittivity to the air.
Description is now made of a specific example of embodiment of the present invention.
The ground conductor 1 was formed, as illustrated in
Component parts of a configuration in part of
By the foregoing arrangement, the configuration in part of
According to the present invention, a triplate line-to-waveguide transducer is made up by component members such as a ground conductor 1, an upper ground conductor 5, and metallic spacers 7a and 7b that can be fabricated at a low cost by a punching, such as of a metallic plate with a desirable thickness, allowing for facile fabrication and high connection integrity, at a low cost, with a minimized lower limit of resonance frequency relative to a conventional configuration, without detriment to a low-loss characteristic over a wide bandwidth in the past.
Number | Date | Country | Kind |
---|---|---|---|
P2007-074529 | Mar 2007 | JP | national |
P2007-138194 | May 2007 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2008/053300 | 2/26/2008 | WO | 00 | 9/22/2009 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2008/114580 | 9/25/2008 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2877429 | Sommers et al. | Mar 1959 | A |
4562416 | Sedivec | Dec 1985 | A |
6545572 | Oath et al. | Apr 2003 | B1 |
20070229380 | Dota et al. | Oct 2007 | A1 |
Number | Date | Country |
---|---|---|
1 592 081 | Nov 2005 | EP |
1 860 731 | Nov 2007 | EP |
H6-70305 | Sep 1994 | JP |
2004-215050 | Jul 2004 | JP |
WO 2006098054 | Sep 2006 | WO |
Number | Date | Country | |
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20100085133 A1 | Apr 2010 | US |