A phenomenological study in d-spatial dimensions is presented for the coexistence of planar antiferromagnetism and type H superconductivity. In this approach critical temperatures in the range 30-1 O0 K arise due to the proposed coupling of magnons and conduction electron pairs. We discuss some remarkable features of oxide ceramics, including a longer London penetration depth, shorter coherence length, lower Hol, higher He2, large current densities, and large pinning force.