Flat adjustable capacitor for magnetic resonance scanner

A compensation capacitor for an antenna of a magnetic resonance scanner, the compensation capacitor comprising:

• a first electrode;
• a second electrode, wherein the first electrode and the second electrode are arranged in parallel;
• a third electrode, wherein the third electrode and the second electrode are arranged in parallel, and wherein the first electrode and the third electrode are arranged side by side opposite a first surface of the second electrode;
• and
• an insulator configured to resist high voltages, wherein the insulator is arranged between the first electrode and the second electrode, between the second electrode and the third electrode, and between the first electrode and the third electrode,
• wherein the second electrode is configured to move relative to the first electrode such that a surface area of a projection of a surface of the first electrode along a surface normal of the first electrode to the first surface of the second electrode is variable, and
• wherein the second electrode is configured to move relative to the third electrode such that a surface area of a projection of a surface of the third electrode along a surface normal of the third electrode to the first surface of the second electrode is variable.

An antenna for a magnetic resonance scanner, the antenna comprising:

• a compensation capacitor having:
• a first electrode;
• a second electrode, wherein the first electrode and the second electrode are arranged in parallel;
• and
• an insulator configured to resist high voltages arranged between the first electrode and the second electrode;
• and
• a dielectric with low dielectric losses arranged between the insulator and the second electrode,
• wherein one or both of the second electrode and the dielectric are configured to move relative to the first electrode such that a surface area of a projection of a surface of the first electrode along a surface normal of the first electrode to one or both of a surface of the second electrode and a surface of the dielectric is variable.