VARIABLE LENGTH TRANSMISSION LINE

• US 3,763,445 A
• Filed: 03/08/1971
• Issued: 10/02/1973
• Est. Priority Date: 03/08/1971
• Status: Expired due to Term

• Current Assignee: Cornelis T. Veenendaal, David A. Hannaford
• Original Assignee: Cornelis T. Veenendaal, David A. Hannaford
• Inventors: Hannaford, David A., Veenendaal, Cornelis T.
• Primary Examiner(s): Rolinec, Rudolph V.
• Assistant Examiner(s): Punter, Wm. H.
• Application Number:
  US05/121,807
• Time in Patent Office: 939 Days
• Field of Search: 333/31R,97R,96,84M
• US Class Current: 333/160
• CPC Class Codes: H01B 11/1895 Particular features or applications
• CPC Class Codes: H01P 1/183 Coaxial phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01P 9/00 Delay lines of the waveguide type

Abstract

A pair of movable U-shaped inner conductors for portions of a transmission line each have yoke elements secured to a slide positioned in a chamber in a metal housing and parallel leg elements slidably received in the ends of corresponding stationary tubular conductors also positioned in the housing and forming inner conductors of other portions of the transmission line. Two of the stationary conductors have other ends terminating in external connectors at one end of the housing and a third stationary conductor is U-shaped to provide a continuous inner conductor between the conductors. The casing is the outer conductor for the transmission line and has inner conducting wall surfaces spaced predetermined distances from the different portions of inner conductor to provide a substantially uniform characteristic impedance along the transmission line. A rotatable worm member journaled in the casing and threaded through the slide is rotatable to move the slides and U-shaped movable conductor members relative to the housing and stationary conductor members to vary the length of the transmission line.

Claims

1. A variable length transmission line comprising:

stationary outer conductor means surrounding stationary hollow inner conductor means defining coaxial transmission line means extending parallel to each other, adjacent outer ends of said stationary hollow inner conductor means being connected together by curved stationary hollow inner conductor means;

movable inner conductor means having parallel leg means each having one end received in sliding electrical relationship in one end of one of said stationary hollow inner conductor means and having connecting section means connecting the other ends of said leg means together;

housing means having a recess therein with said movable inner conductor means being disposed therein and movable therealong;

said recess having conducting surface means provided by said housing means extending along each side of said movable inner conductor means and being spaced from said movable inner conductor means thereby defining an outer conductive means therefor so that said coaxial transmission line means, said conducting surface means and said movable inner conductor means provide said transmission line with substantially uniform characteristic impedance therealong;

slide means disposed in said chamber connected to said movable inner conductor means and being movable along said recess to move said movable inner conductor means relative to said housing means and said parallel leg means relative to said stationary hollow inner conductor means to vary the length of said transmission line; and

means to said slide means for moving said slide means and said movable inner conductor means along said recess.

2. A variable length transmission line comprising:

stationary outer conductor means surrounding stationary hollow inner conductor means defining coaxial transmission line means extending parallel to each other;

movable inner conductor means having parallel leg means each having one end received in sliding electrical relationship in one end of one of said stationary hollow inner conductor means and having connecting section means connecting the other ends of said leg means together;

housing means having a recess therein with said movable inner conductor means being disposed therein and movable therealong;

said recess having conducting surface means provided by said housing means extending along each side of said movable inner conductor means and being spaced from said movable inner conductor means thereby defining an outer conductive means therefor so that said coaxial transmission line means, said conducting surface means and said movable inner conductor means provide said transmission line with substantially uniform characteristic impedance therealong;

slide means disposed in said recess having insulation means connected to said connecting section means, said connecting section means being of lesser size than said leg means, said slide means being movable along said recess to move said movable inner conductor means relative to said housing means and said parallel leg means relative to said stationary hollow inner conductor means to vary the length of said transmission line; and

means connected to said slide means for moving said slide means and said movable inner conductor means along said recess.

3. A variable length transmission line according to claim 1 wherein said coaxial transmission line means is disposed in said housing means and said conducting surfaces constitute said stationary outer conductor means.

4. A variable length transmission line according to claim 1 wherein said coaxial transmission line means are in parallel.

5. A variable length transmission line according to claim 1 wherein said means for moving said slide means includes a worm member journaled in said housing and extending along said recess parallel to said leg means of said movable inner conductor means, said slide means having thread areas threadably engaging said worm member.

6. A variable length transmissiOn line according to claim 1 wherein said conducting surface means are positioned closer to said movable inner conductor means than said stationary outer conductor means are positioned with respect to said stationary hollow inner conductor means.

7. A variable length transmission line according to claim 1 wherein said connecting section means has an arcuate configuration.