A transmission line (218) is formed to have a characteristic impedance which increases at a first substantially exponential rate with respect to a distance from the input (202). A plurality of resonators (206-214) are coupled to the transmission line and positioned at a plurality of locations along the...http://www.google.com/patents/US6768398?utm_source=gb-gplus-sharePatent US6768398 - Method and apparatus for creating a radio frequency filter
