MICROSTRIP LINE FILTER

摘要

Provided is a small-sized microstrip line filter, which suppresses the deterioration of a conforming percentage due to a bleeding or a cutting error, thereby to reduce the dispersion of frequency characteristics. Principal plane lines (6A - 6D) of the microstrip line filter are formed on the surface principal face of a dielectric substrate (1). Side face lines (5A - 5D, and 9A - 9D) are formed on the side faces. A ground electrode (4) and input/output electrodes (2A and 2B) are formed on the back principal face. Electrode extending portions (4A - 4F) disposed at the end side of a back principal face (1A) are formed in the ground electrode (4), such that the electrode extending portions (4A - 4F) and the input/output electrodes (2A and 2B) are spaced from each other by electrode non-forming portions (3A - 3F). The back principal face (1A) is enclosed by the electrode extending portions (4A - 4F), the electrode non-forming portions (3A - 3F) and the input/output electrodes (2A and 2B), and the principal plane lines (6A - 6D) are made conductive to the electrode extending portions (4A - 4F) through the side face lines (5A - 5D).