| 摘要 |
An RF coupling device is formed on a hybrid printed circuit which avoids discrete capacitors or resistors. The substrate is formed of refractory dielectric sheet, such as alumina or another ceramic. A printed conductor is printed on the front surface of the substrate, and has one or more broadened portions formed on it as capacitor plates. One or more printed resistors are in contact with the printed conductor. A ground pad is printed in a predetermined pattern onto a portion of the reverse surface of the substrate at selected locations. The ground pad has one or more portions that are in registry with the capacitor plates and serve as grounded plates for the capacitors. One or more inductors can be printed onto the substrate in a meander pattern and in contact with the remainder of the printed conductor. The printed circuit receives one or more RF transformers whose leads can be soldered to the printed circuit. RF coupling devices such as a filter, a directional coupler, a two way signal splitter, and a four-way signal splitter can be constructed according to this technique. The capacitors formed as described are generally associated with high Q values which help reduce insertion loss and also increase frequency bandwidth.
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