| 摘要 |
PURPOSE:To adjust characteristic impedance, and to make a branching filter compact by providing a void by a frame part for-mounting a cover on an impedance matching circuit formed of strip lines. CONSTITUTION:A frame body formation layer 18 as an upper layer, strip line formation layer 19, terminal formation layer 20, and foot pattern formation layer 21 are formed like a a ladder so as to be cone-shaped. Then, a signal terminal and a ground terminal forming a pattern on the layer 20 are connected with the signal terminal and the ground terminal formed on the back face of the layer 21 by through-holes. Also, filter chips F1 and F2 are provided on the surface of the layer 21, and connected with the signal terminal and the ground terminal formed on the layer 20 by wire-bonding. Then, three strip lines 22 are provided on the layer 19, trimming-processed, and circuit-connected by the wire bonding. Thus, the void is provided at the upper part of the layer 19, so that the characteristic impedance can be adjusted, and the branching filter can be made compact. |
