... on the other end, resulting in a virtualgrounding. Therefore, the physical groundings of the resonators in Figure 5.23(a)may be removed and replaced with the virtual groundings produced by the ... output.can only be electrically equivalent to the combline filter in the vicinity of the mid-band frequency, and its stopband behavior is different from that of the combline fil-ter.Similar to the ... compact, but requires use of groundingmicrostrip resonators, which is usually accomplished with via holes. However, be-cause the resonators are quarter-wavelength long using the grounding, the...