High frequency filter

A high frequency filter comprising:

• a multilayer substrate including a first multilayered substrate for which a first electric conduction pad including multiple lands formed along a layering direction of the multilayer substrate is provided, the multiple lands forming a capacitance, a second multilayered substrate for which a second electric conduction pad including multiple lands formed along the layering direction is provided, the multiple lands forming a capacitance, and a third multilayered substrate for which a third electric conduction pad including multiple lands formed along the layering direction is provided, the multiple lands forming a capacitance, the third substrate being sandwiched between the first substrate and the second substrate;
• a first columnar conductor provided in such a way as to penetrate the multilayer substrate, and electrically connected to the first electric conduction pad, the second electric conduction pad and the third electric conduction pad, a signal being input to and output from the first columnar conductor via both ends of the multilayer substrate in the layering direction;
• and
• multiple second columnar conductors provided in such a way as to penetrate the multilayer substrate and to surround the first columnar conductor, electrically connected to a ground plane provided on a first main surface of the first substrate, the first main surface being opposite to a second main surface facing the third substrate, and electrically connected to a ground plane provided on a first main surface of the second substrate, the first main surface being opposite to a second main surface facing the third substrate,
• wherein the first columnar conductor and the second columnar conductors constitute a coaxial line in which the first columnar conductor functions as an inner conductor and the second columnar conductors function as an outer conductor, and
• in the first columnar conductor, a portion corresponding to a spacing between the first electric conduction pad and the third electric conduction pad and a portion corresponding to a spacing between the second electric conduction pad and the third electric conduction pad are electrical lengths of 90 degrees or less at a center frequency of a stopband where transmission of a signal is rejected.