Stripline variable phase shifter having means to maintain a constant characteristic impedance

Claim 1

A PRINTED CIRCUIT PHASE SHIFTER COMPRISING: A FIRST PLANAR CONDUCTOR PROVIDING A FIRST GROUND PLANE; A SECOND PLANAR CONDUCTOR DISPOSED IN PARALLEL WITH SAID FIRST PLANR CONDUCTOR PROVIDING A SECOND GROUND PLANE; A FIRST STRUCTRUAL DIELECTRIC DISPOSED BETWEEN SAID FIRST AND SECOND PLANAR CONDUCTORS; A PAIR OF ELONGATE, INNER, PLANAR CONDUCTORS DISPOSED IN AN INNER PLANE INTERMEDIATE SAID FIRST AND SECOND GROUND PLANES, SAID PLANAR CONDUCTORS AND SAID FIRST DIELECTRIC FORMING A PRINTED CIRCUIT BOARD, ONE END OF EACH OF SAID INNER PLANAR CONDUCTORS BEING IN PARALLEL RELATIONSHIP WITH EACH OTHER; EACH OF SAID INNER PLANAR CONDUCTORS BEING CONNECTED TO A TRANSMISSION LINE CONNECTOR MEANS FOR CONNECTING SAID PHASE SHIFTER IN A TRANSMISSION LINE SYSTEM, SAID PRINTED CIRCUIT BOARD HAVING AN ELONGATED CHANNEL THE DEPTH OF WHICH IS COINCIDENT WITH SAID PLANE OF SAID PAIR OF INNER CONDUCTORS; A DIELECTRIC SLIDER DISPOSED FOR SLIDING MOVEMENT IN SAID CHANNEL; A GENERALLY, U-SHAPED, ELONGATED, INNER CONDUCTOR DISPOSED ON A LOWER SURFACE OF SAID SLIDER SUPERIMPOSED ON, SLIDABLY ENGAGING SAID PAIR OF INNER PLANAR CONDUCTORS, SAID USHAPED INNER CONDUCTOR BEING SUBSTANTIALLY WIDER THAN SAID PARALLEL INNER CONDUCTORS SO AS TO MAKE THE IMPEDANCE OF SAID PHASE SHIFTER PRIMARILY THAT OF SAID U-SHAPED CONDUCTOR, THUS ALLOWING SAID PHASE SHIFTER TO MAINTAIN A CONSTANT IMPEDANCE OVER THE ENTIRE RANGE OF PHASE VARIATIONS, SAID SLIDER HAVING A THIRD PLANAR CONDUCTOR BEING COPLANAR WITH SAID SECOND GROUND PLANE, SAID SLIDER MEANS HAVING A FOURTH PLANAR CONDUCTOR ELECTRICALLY CONNECTED TO SAID THIRD PLANAR CONDUCTOR AND BEING IN A PLANE ELEVATED WITH RESPECT TO SAID SECOND GROUND PLANE AND EXTENDING OVER THE AREA OCCUPIED BY SAID U-SHAPED INNER CONDUCTOR FOR PROVIDING AN UNBALANCED GROUND PLANE FOR SAID U-SHAPED INNER CONDUCTOR WITH RESPECT TO SAID PAIR OF INNER CONDUCTORS AND A SECOND STRUCTURAL DIELECTRIC DISPOSED ON SAID THIRD AND FOURTH PLANAR CONDUCTORS OF SAID SLIDER AND FORMING SAID LOWER SURFACE OF SAID SLIDER.