Compact broadband C-shaped stacked microstrip antennas

Microstrip antennas (MSA) have several advantages, like light weight, small volume, and low profile planar configuration. However, their main disadvantage is small VSWR bandwidth. Also, the area of an MSA for frequencies in the UHF band is large. Many techniques have been reported for obtaining compact broadband MSAs (see Sanad, M., 1994; Kosiavas, G. et al., 1989; Kapur, R. and Kumar, G., 1999). Compact broadband stacked configurations of C-shaped MSA with C, H and ring MSAs are discussed. All the MSAs have been analyzed using the method of moment based IE3D software from Zeland Software Inc, followed by experimental verifications. The theoretical and experimental results are in good agreement. A C-shaped with a ring MSA gives largest bandwidth of all, with a higher cross-polar level whereas C-shaped with C-shaped gives the lowest cross-polar level.