摘要 |
An ultra wideband, frequency dependent attenuator apparatus for providing a loss which can be matched with a physically longer, given delay line, but yet which provides a much shorter time delay than the physically longer, given delay line with constant group delay. The apparatus is formed by an ordinary microstrip transmission line placed in series with an engineered lossy microstrip transmission line, with both transmission lines being placed on a substrate to effectively form a hybrid microstrip transmission line. The lossy transmission line includes resistive material placed along the opposing longitudinal edges thereof. In one embodiment, spaced apart metal tracks are formed along each strip of resistive material to provide the lossy microstrip transmission line with a desired loss characteristic. The apparatus can be used as one element in a delay bank to provide a loss which is matched to an associated delay line having a longer physical length, but which still provides a shorter time delay than the longer delay line with a constant group delay.
|