Filter device and radio-frequency front-end circuit equipped with the same

A filter device comprising:

• a multilayer body including a plurality of dielectric layers;
• an input terminal;
• an output terminal;
• a grounding terminal;
• a resonant circuit including a plurality of resonators;
• a first inductor that conductively connects the input terminal to the grounding terminal;
• a second inductor that conductively connects the output terminal to the grounding terminal;
• a first flat electrode and a second flat electrode spaced apart from each other in a lamination direction in the multilayer body;
• and
• a first shield conductor and a second shield conductor that are connected to the grounding terminal;
• wherein
• the resonant circuit is between the first flat electrode and the second flat electrode and includes the plurality of resonators extending in a first direction perpendicular or substantially perpendicular to the lamination direction;
• the first shield conductor and the second shield conductor are on a first side surface and a second side surface of the multilayer body, respectively, which are perpendicular to the first direction and are connected to the first flat electrode and the second flat electrode;
• the plurality of resonators are arranged in the multilayer body in a second direction perpendicular or substantially perpendicular to both the lamination direction and the first direction;
• respective first end portions of the plurality of resonators are connected to the first shield conductor and respective second end portions of the plurality of resonators are spaced apart from the second shield conductor;
• and
• the input terminal and the output terminal are capacitively coupled to the resonant circuit.