Non-contacting radio frequency power coupler for relative linear motion

An electric coupler for connecting a first high frequency device to a second high frequency device, said coupler arranged to permit relative linear movement between said first and second devices, said devices having a mean electrical energy operating wavelength of .lambda., said coupler comprising a first pair of parallel conductor members each having generally tubular walls, each of said first conductor members having an axially extending opening through the wall thereof, first terminal means at corresponding first ends of said first pair of conductor members electrically connecting them across said first device, means for electrically coupling the first pair of conductor members together, a second pair of conductor members disposed one within each of said first conductor members, said second conductor means being insulated from the walls of said first conductor members, said second conductor members being moveable axially within the relative to said first conductor members and having a length substantially equal to .lambda./4, and second terminal means for electrically connecting said second pair of conductor members across said second device, said second terminal means being connected to said second conductor members at corresponding first ends thereof relatively adjacent said first ends of said first pair of conductor members, said second terminal means extending through said axially extending openings through the walls of said first conductor members, said means for electrically coupling said first conductor members together comprising first and second generally tubular members disposed in spaced relationship one about each of said first conductor members and a compound tubular member enclosing said first and second tubular members, said compound tubular member having a common wall member between said first and second tubular members, and an electrically conducting end wall member connecting said first, second, and compound tubular members together, said end wall member supporting said first and second tubular members in spaced relation within said compound tubular member, said first, second, and compound tubular members all having a length substantially equal to .lambda./4 and arranged for relative axial movement along said first conductor members, said end wall member being located at the end of said first, second, and compound tubular members closest to said second conductor members and being spaced from the second terminal means by a distance substantially equal to .lambda./4, and non-conducting means supporting said coupling means to move with said second device.