Method and apparatus for a coaxial high power RF combiner
A high power electrical signal power combiner including coaxial and integrated waveguide structures, and including thermal stress relief elements and impedance transformation elements is designed and constructed.
1 . A power combiner comprising:
an electrical signal power combiner housing;
a first pair of input ports and a second pair of input ports, wherein each said input port connects to an input coaxial transmission line into said power combiner housing;
a plurality of coaxial transmission line to waveguide transitions within said housing, wherein each said input coaxial transmission line connects to a coaxial input of one of each coaxial to waveguide transitions;
a first waveguide junction within said housing connected to each of two waveguide transitions from said first pair of input ports, and having a waveguide output;
a second waveguide junction within said housing connected each of two waveguide transitions from said second pair of input ports, and having a waveguide output;
a first waveguide transmission line within said housing connected at one end to an output of said first waveguide junction and at the other end to a third waveguide junction within said housing;
a second waveguide transmission line within said housing connected at one end to said second waveguide junction and at the other end to said third waveguide junction;
a mechanical stress relief waveguide within said housing connected at one end to an output of said third waveguide junction, and connected at the other end to a waveguide to coaxial transmission line transition within said housing; and
an output coaxial transmission line connected at one end to said waveguide to coaxial transmission line transition, and at the other end output of said housing to an output port.
2 . The power combiner of claim 1 , wherein said input ports and said output port is a radio frequency (RF) connector.
3 . The power combiner of claim 1 , wherein said first waveguide transmission line and said second waveguide transmission line are each single ridged waveguide.
4 . The power combiner of claim 1 , wherein said plurality of coaxial transmission line to waveguide transitions and said waveguide to coaxial transmission line transition are each a current probe transition type.
5 . The power combiner of claim 1 , wherein said mechanical stress relief waveguide is shaped with two right angle bends to allow expansion and contraction with a changing self temperature.
6 . The power combiner of claim 5 , wherein said mechanical stress relief waveguide forms a mechanical stress relief loop.
7 . The power combiner of claim 1 , wherein coaxial transmission lines further comprise a PTFE insulator material between a center conductor and the outer conductor.
8 . The power combiner of claim 7 , wherein said plurality of coaxial transmission line to waveguide transitions and said waveguide to coaxial transmission line transition have mechanical flexibility at an interface between said PTFE and an outer conductor of said waveguide transitions, to allow expansion and contraction with a changing self temperature.
9 . The power combiner of claim 1 , wherein said plurality of coaxial transmission line to waveguide transitions further comprise input 50 ohms impedance at each input, and a combined output impedance of 25 ohms.
10 . The power combiner of claim 9 , wherein said waveguide to coaxial transmission line transition further comprises input 25 ohms impedance at each input, and a combined output impedance of 50 ohms.
11 . The power combiner of claim 1 , wherein said first waveguide transmission line and said second waveguide transmission line each form part of a cooling structure providing thermal dissipation to said housing.
12 . (ORIGINAL The power combiner of claim 1 , wherein said power combiner is operable to combine electrical signals input to said power combiner into a combined total power electrical signal output.
13 . A radio frequency (RF) electrical signal power combiner comprising:
four RF input ports, wherein each said input port further comprises an RF connector attached to an exterior of said RF electrical signal power combiner, and attached 50 ohms coaxial transmission line into an interior of said electrical signal power combiner;
four coaxial to waveguide transitions, each electrically connected to each said 50 ohms coaxial transmission line, in pairs;
two 2:1 single ridged waveguide combiners and impedance transformers, each operably combining two input RF electrical signals into a combined output power electrical signal, and operably transforming said input RF electrical signals at said 50 ohms impedances to an output 25 ohms impedance;
two RF waveguide transmission lines, each electrically operably connected to the output of said single ridged waveguide combiners and impedance transformers, each with transmission line impedance of 25 ohms, and each mechanically attached to an interior of a housing, said mechanical attachment providing for thermal dissipation of heat generated by said electrical signal power combiner;
a single ridged coupled waveguide 2:1 power combiner electrically operably combining two inputs from each of two said RF waveguide transmission lines, said combining primarily by electrical coupling, and having input impedance of 25 ohms and output impedance of 50 ohms;
a thermal stress relief half-loop waveguide transmission line connected to said output of said single ridged coupled waveguide 2:1 power combiner;
a 50 ohms coaxial transmission line connected to said thermal stress relief half-loop waveguide transmission line from the interior of said electrical signal power combiner to the exterior of said RF electrical signal power combiner; and
an RF output ports, wherein said output port further comprises an RF connector attached to an exterior of said RF electrical signal power combiner, and attached to said 50 ohms coaxial transmission line from an interior of said electrical signal power combiner.
14 . A method of constructing an electrical signal power combiner comprising:
constructing a metallic housing, wherein said metallic housing further comprises waveguide structures as part of said housing;
applying a coating to said housing; and
assembling one or more connectors and coaxial transmission lines into said housing, wherein at least one of the coaxial connectors is an N-Type connector,
wherein said coating is a conductive metallic coating.
15 . The method of claim 14 , wherein said waveguide structures further comprise a coaxial to waveguide transition and impedance transformer at each input, a 2:1 waveguide combiner for each pair of said coaxial to waveguide transition and impedance transformers, a single ridged waveguide transmission line for each 2:1 waveguide combiner, a 2:1 coupled waveguide combiner for each pair of said single ridged waveguide transmission lines, and a mechanical stress relief output waveguide to coaxial transition at an output.
16 . The method of claim 14 , wherein said waveguide structures are machined from a same material as said housing, as a single constructed piece.
17 . The method of claim 14 , wherein said assembling connectors and coaxial transmission lines into said housing further comprises electrically and mechanically connecting a connectors center conductors to a coaxial to waveguide transition and impedance transformer at each input, and to a mechanical stress relief output waveguide to coaxial transition at an output.