Resonator, filter, duplexer, and high-frequency circuit apparatus

A resonator comprising:

• a dielectric member;
• and
• an electrode formed on the dielectric member, the electrode having:
• a first portion formed from a plurality of electrode patterns, the first portion defining a displacement area in a first interface between the dielectric member and the electrode in which a first electric field has a higher vertical component than a predetermined threshold so that a displacement current flow is substantially uniform over the first interface, and
• a second portion formed from alternately layered conductive thin films and a dielectric thin film, the second portion having a steady area provided in a second interface between the dielectric member and the electrode in which a second electric field has a lower vertical component than the predetermined threshold, wherein
• the plurality of electrode patterns of the first portion and the conductive thin films of the second portion are respectively connected to each other.

A resonator comprising:

• a dielectric member;
• and
• an electrode formed on the dielectric member, the electrode having:
• a first portion formed from alternately layered conductive thin films and a dielectric thin film, the first portion having a steady area provided in a first interface between the dielectric member and the electrode in which a first electric field has a lower vertical component than a predetermined threshold, and
• a second portion formed from an electrode pattern which is divided into substantially congruent electrode patterns of an integer multiple of the number of conductive thin films of the first portion, the second portion defining a displacement area in a second interface between the dielectric member and the electrode in which a second electric field has a higher vertical component than the predetermined threshold, wherein
• the electrode patterns of the second portion and the conductive thin films of the first portion are respectively connected to each other.