Summary form only given, as follows. This paper presents a novel geometry for the realization of TM dual-mode cavities and filters having asymmetric filtering characteristics. In contrast to previous works, that are limited to structures with symmetric responses, the proposed cavity does not employ any intra-coupling elements, while the source and load of the cavity are directly coupled to both resonant modes. A two-cavity TM dual-mode filter with a pair of transmission zeros below the pass-band has been designed and manufactured.