Triplate line-to-waveguide transducer having spacer dimensions which are larger than waveguide dimensions
A ground conductor ( 1 ) has a through hole provided through an area thereof for connection with a waveguide ( 6 ), with dimensions substantially equal to cavity dimensions of the waveguide ( 6 ), and a metallic spacer ( 7 a ) is provided as a holding element for a film substrate ( 4 ), with an even thickness to a dielectric substrate ( 2 a ), the metallic spacer ( 7 a ) having dimensions E 1 and E 2 of cavity walls thereof changed in accordance with a desirable frequency, and cooperating with another metallic spacer ( 7 b ) having substantially equal dimensions to the metallic spacer ( 7 a ), to sandwich the film substrate ( 4 ) in between, and in addition, an upper ground conductor ( 5 ) is arranged on the other metallic spacer ( 7 b ), and a quadrate resonant patch pattern ( 8 ) is formed at an end of the strip line conductor ( 3 ) formed to the film subs ate ( 4 ), on an area corresponding to a transducer end of the waveguide ( 6 ), while a combination of the quadrate resonant patch pattern ( 8 ) and the waveguide ( 6 ) is arranged such that the quadrate resonant patch pattern ( 8 ) has a center position thereof coincident with a center position of the cavity dimensions of the waveguide ( 6 ).
1. A triplate line-to-waveguide transducer including a transducer portion configured with and between a waveguide having a waveguide cavity and a triplate transmission line comprised of a film substrate formed with a strip line conductor and laminated over a surface of a lower ground conductor, with a first dielectric substrate in between; and an upper ground conductor laminated over a surface of the film substrate, with a second dielectric substrate in between, the triplate line-to-waveguide transducer comprising:
a through hole provided through an area on the lower ground conductor for connection with the waveguide, the through hole having dimensions substantially equal to cavity dimensions of the waveguide cavity;
a first metallic spacer provided as a holding element for the film substrate, with an even thickness to the first dielectric substrate and a first metallic spacer cavity defined by cavity dimensions larger than the cavity dimensions of the waveguide cavity, and cooperating with a second metallic spacer having a second metallic spacer cavity having cavity dimensions substantially equal to the cavity dimensions of the first metallic spacer cavity, to sandwich the film substrate in between;
the upper ground conductor being arranged on the other second 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 cavity.
2. The triplate line-to-waveguide transducer according to claim 1 , wherein the quadrate resonant patch pattern has a dimension thereof in a direction of line connection set as a free space wavelength λ 0 of desirable frequency times 0.30 to 0.34, and a dimension thereof in a direction perpendicular to the direction of line connection set as the free space wavelength λ 0 of desirable frequency times 0.32 to 0.4.
3. The triplate line-to-waveguide transducer according to claim 2 , wherein the cavity dimensions of the first metallic spacer cavity and the cavity dimensions of the second metallic spacer cavity are set as a free space wavelength λ 0 of desirable frequency times 0.56 to 0.62.
4. The triplate line-to-waveguide transducer according to claim 1 , wherein the cavity dimensions of the first metallic spacer cavity and the cavity dimensions of the second metallic spacer cavity are set as a free space wavelength λ 0 of desirable frequency times 0.56 to 0.62.
5. The triplate line-to-waveguide transducer according to claim 1 , wherein an area dimension of the first metallic spacer cavity and an area dimension of the second metallic spacer cavity are both greater than an area dimension of the through hole provided through the lower ground conductor and an area dimension of the waveguide cavity.