Coaxial transmissioin line input transformer having externally variable eccentricity and position

An input system for a microwave amplifier, comprising:

• a resonant cavity having an electron beam projected therethrough, said cavity characterized by a first inductance, said electron beam providing a resistive load;
• a coupling loop disposed within said cavity, said coupling loop characterized by a second inductance coupled to said first inductance;
• a window electrically coupled to said coupling loop characterized by a vacuum barrier for said resonant cavity, said window further characterized by a capacitance in parallel with said second inductance;
• a transmission line electrically coupled to said window and an input transformer disposed on said transmission line characterized by variable input impedance;
• and
• an RF source coupled to and providing an RF input signal to said transmission line;
• said input transformer further comprises:
• a housing having an inner wall;
• a center conductor in electrical connection with said transmission line disposed along an axis of said housing;
• a first sleeve disposed within said housing, said first sleeve having an outer wall in electrical contact with said inner wall of said housing, and an inner wall eccentrically disposed relative to said outer wall, said first sleeve being capable of axial motion relative to said housing to thereby change a phase of oscillation of said RF input signal;
• a second sleeve disposed within said first sleeve, said second sleeve having an outer wall in electrical contact with said inner wall of said first sleeve, and an inner wall eccentrically disposed relative to said outer wall of said second sleeve, said second sleeve being capable of angular motion relative to said first sleeve to thereby change an amplitude of said RF input signal;
• and
• an air gap defined between said center conductor and said inner wall of said second sleeve;
• wherein said first inductance, said second inductance, said capacitance and said input transformer collectively characterize a bandpass filter, and said RF source has an impedance matched to said resistive load by said bandpass filter.

A transformer for use with a transmission line, comprising:

• a center conductor adapted for electrical connection with said transmission line;
• a housing having an inner wall coaxial with a longitudinal axis of said center conductor;
• a first sleeve enclosed by said housing, said first sleeve having an outer wall in electrical contact with said inner wall of said housing, and having a cylindrical inner wall oriented eccentric with respect to said longitudinal axis;
• a second sleeve enclosed by said first sleeve, said second sleeve having an outer wall in electrical contact with said inner wall of said first sleeve, said second sleeve having an inner wall oriented eccentric with respect to said outer wall of said second sleeve;
• a gap defined between said center conductor and said inner wall of said second sleeve;
• first means disposed between said outer wall of said first sleeve and said inner wall of said housing for permitting movement of said first sleeve in an axial direction relative to said housing;
• and
• second means disposed between said inner wall of said first sleeve and said outer wall of said second sleeve for permitting movement of said second sleeve in an angular direction relative to said first sleeve.

An input system for a microwave amplifier, comprising:

• a resonant cavity having an electron beam projected therethrough, said cavity characterized by a first inductance, said electron beam providing a resistive load;
• a coupling loop disposed within said cavity, said coupling loop characterized by a second inductance coupled to said first inductance;
• a window electrically coupled to said coupling loop characterized by a vacuum barrier for said resonant cavity, said window further characterized by a capacitance in parallel with said second inductance;
• a transmission line electrically coupled to said window and an input transformer disposed on said transmission line characterized by continuously variable input impedance and position, said input transformer comprising at least one rotatable sleeve;
• and
• an RF source coupled to and providing an RF input signal to said transmission line;
• wherein said first inductance, said second inductance, said capacitance and said input transformer collectively characterize a bandpass filter, and said RF source has an impedance matched to said resistive load by said bandpass filter, and rotation of said at least one sleeve changes an amplitude characteristic of said RF input signal.

A transformer for use in varying the amplitude and phase of oscillation of an electromagnetic wave travelling on a transmission line, comprising:

• a housing having an inner wall;
• a center conductor disposed along an axis of said housing, said center conductor adapted for electrical connection with said transmission line;
• a first sleeve enclosed by said housing, said first sleeve having an outer wall in electrical contact with said inner wall of said housing, said first sleeve being capable of axial motion relative to said housing to thereby change said phase of oscillation of said electromagnetic wave;
• a second sleeve enclosed by said first sleeve, said second sleeve having an outer wall in electrical contact with an inner wall of said first sleeve, said second sleeve being capable of angular motion relative to said first sleeve to thereby change said amplitude of said electromagnetic wave;
• an air gap defined between said center conductor and said second sleeve.