摘要 |
<p>A dual mode filter (200, 500, 900) comprising an input (Pin) and an output port (Pout) and a non-conducting substrate (205, 505), and first (215, 510, 902) and second (210, 540, 901) conductors which connect the input port to the output port. The conductors are arranged on or in the substrate, and the first conductor is longer than the second conductor by 50%. Either the first or the second conductor comprises a perturbation element (208, 530, 915) at a central position. The first conductor is arranged between the input port and the output port with a number of sections (216-222; 511-519; 931-933, 936-938), at least some of which are parallel to each other, and arranged so that the current in a section which has one or more other sections in parallel to it always flows in the same direction as the current in the most adjacent of said other sections.</p> |