SPACE-WAVE EFFICIENCY OF ELECTRICALLY THICK CIRCULAR MICROSTRIP ANTENNAS

A new very simple expression is presented for the space-wave efficienc y of electrically thick circular microstrip antennas. It is derived fr om numerical results available in the literature, and is valid for the complete range of relative dielectric constants and the thicknesses o f substrates which are normally used. It also provides insight into th e fundamental influence of the substrate parameters on the space-wave efficiency of the circular microstrip antennas. The results obtained b y using this expression are in conformity with those reported elsewher e.