A slot fed microstrip patch antenna (300) includes a conducting ground plane (308), the conducting ground plane (308) including at least one slot (306). A dielectric material is disposed between the ground plane (308) and at least one feed line (317), wherein at least a portion of the dielectric layer (313) includes magnetic particles (324). The dielectric layer between the feed line (317) and the ground plane (308) provides regions having high relative permittivity (313) and low relative permittivity (312). At least a portion of the stub (318) is disposed on the high relative permittivity region (313).