摘要 |
<p>A filter device having a frame made of plated steel sheet generates a smaller insertion loss and is excellent in productivity. Resonant elements are shaped into a cylindrical form by bending the steel sheet, whose both sides are plated, before they are placed in a filter housing. A gap formed on a lateral face of the resonant element is brazed with solder, and an outer plated face of the resonant element is brazed with solder to an inner plated face of the frame.</p> |