Adjustable phase-inverting coupling loop

An apparatus, comprising:

• a first cavity resonator;
• a second cavity resonator;
• and
• a conductor coupled between the first cavity resonator and the second cavity resonator, wherein a first portion of the conductor defines a first area in a lane that is substantially perpendicular to a first magnetic field direction in the first cavity resonator and a second portion of the conductor defines a second area in a plane that is substantially perpendicular to a second magnetic field direction in the second cavity resonator such that inductive current generated in the first portion flows in substantially the same direction as current in the second portion of the conductor, wherein the first area and the second area determine a coupling constant between electromagnetic fields in the first cavity resonator and the second cavity resonator, wherein a phase of an electromagnetic wave in the first cavity resonator is inverted when transmitted to the second cavity resonator by the conductor relative to a traditional U-shaped conductor solution, and wherein the conductor is rotatably adjustable about an axis.

An apparatus, comprising:

• a first cavity resonator;
• a second cavity resonator;
• a rotatable conductor coupled between the first cavity resonator and the second cavity resonator, wherein a first portion of the rotatable conductor defines a first area in a plane that is substantially perpendicular to a first magnetic field direction in the first cavity resonator and a second portion of the rotatable conductor defines a second area in a plane that is substantially perpendicular to a second magnetic field direction in the second cavity resonator such that inductive current generated in the first portion flows in substantially the same direction as current in the second portion of the rotatable conductor;
• an aperture between the first cavity resonator and the second cavity resonator, wherein the conductor is deployed in the aperture, and
• at least one conducting bar deployed in the aperture perpendicular to an axis of the rotatable conductor.

A base station, comprising:

• a signal source;
• a filter comprising a plurality of cavity resonators, wherein at least two of the plurality of cavity resonators are coupled by a conductor having a first portion that defines a first area in a plane that is substantially perpendicular to a first magnetic field direction in a first one of the at least two cavity resonators and a second portion that defines a second area in a plane that is substantially perpendicular to a second magnetic field direction in a second one of the at least two cavity resonators such that inductive current generated in the first portion flows in substantially the same direction as current in the second portion;
• and
• a knob external to a housing of the base station, wherein the knob is rotatable to adjust the conductor about an axis to modify the first area and the second area by changing the relative orientation of the conductor and the first and second magnetic field directions.