Abstract: A filter device includes an input terminal, an output terminal, a shield conductor, and a resonant circuit including at least one resonator, and inductors. A first inductor connects the input terminal and the shield conductor. A second inductor connects the output terminal and the shield conductor. The input terminal and the output terminal are capacitively coupled to the resonant circuit.

Abstract: A filter includes a multilayer body, plate electrodes, resonators, shield conductors, and connecting conductors. The multilayer body includes dielectric layers. The plate electrodes are spaced apart from one another in the multilayer body in a lamination direction thereof. The resonators are between the plate electrodes and extend in a first direction orthogonal or substantially orthogonal to the lamination direction. The shield conductors are on lateral surfaces of the multilayer body and are connected to the plate electrodes. The connecting conductors connect the resonators to the plate electrodes. The resonators are side by side in a second direction in the multilayer body. The resonators each include first and second ends. The first ends are connected to the shield conductor, and the second ends are spaced away from the shield conductor.

Abstract: A filter device includes a laminate body including dielectric layers, plate electrodes, resonators, shield conductors, and a capacitive electrode. The plate electrodes are spaced apart from each other in a lamination direction in the laminate body. The resonators are between the plate electrodes and extend in a first direction. The shield conductors are on side surfaces, respectively, that are orthogonal or substantially orthogonal to the first direction in the laminate body, and connected to the plate electrodes. The resonators are provided in a second direction orthogonal or substantially orthogonal to the lamination direction and the first direction in the laminate body. The resonators each include a first end connected to the shield conductor and a second end spaced apart from the shield conductor. The capacitive electrode couples the resonators.

Abstract: A CD-R where a key generating program or the like is stored, and a USB memory where a public key is stored are delivered to a supplier from a receiver. A common key is generated by the supplier. Delivery data which is to be encrypted using the generated common key and a common key which is encrypted using the public key are stored in the CD-R by the supplier. The CD-R and the USB memory are delivered to the receiver by the supplier. The encrypted common key is decrypted by the receiver using a private key. The encrypted delivery data is decrypted by the receiver using the decrypted common key.