Broadband directional couplers for tem and quasi-tem mode guides and lines

A directional coupler operable at microwave and RF frequencies, comprising:

• a main coaxial transmission line segment, comprising an outer cylindrical main line conductor and a center main line conductor fitted concentrically within the outer main line conductor;
• a coupled coaxial transmission line segment adjacent to and oriented at an angle with respect to the main transmission line;
• a first coupling hole formed in the outer conductor of the coupled line, the coupling hole formed at an intersection region between the main and coupled lines;
• and
• a second coupling hole formed in the outer conductor of the main line at the intersection region.

A microstrip to microstrip directional coupler operable at microwave and RF frequencies, comprising:

• a main microstrip transmission line, comprising a main line dielectric substrate, a main line microstrip conductor formed on a first surface of the main line dielectric substrate and a conductive layer formed on the second, opposed, surface of the main line dielectric substrate;
• a coupled microstrip transmission line comprising a coupled line dielectric substrate, the conductive layer sandwiched between the main line dielectric substrate and the coupled line dielectric substrate, and a coupled line microstrip conductor formed on an opposite surface of the coupled line dielectric substrate, the coupled line microstrip conductor oriented at an angle with respect to the main line microstrip conductor;
• and
• a coupling hole formed in the conductor plane at an intersection area between the main line microstrip conductor and the coupled line microstrip conductor.

An impedance tuner, comprising:

• a slab transmission line including opposed conductor slabs or planes and a center conductor positioned between the conductor planes;
• one or more probe carriages mounted for movement through a range of movement in parallel with the center conductor;
• a slab-line-to-coaxial-line directional coupler, comprising:
• a coupled coaxial transmission line comprising a cylindrical outer conductor and a center conductor concentrically positioned within the outer conductor, the coupled transmission line adjacent to and oriented at an angle with respect to the center conductor of the slab transmission line, and passing through holes formed in the opposed conductor planes;
• a coupling hole formed in the outer conductor of the coupled coaxial line, the coupling hole formed at an intersection region between the center conductor and coupled line.