EXTENDED UNIFORM GEOMETRICAL-THEORY OF DIFFRACTION SOLUTION FOR THE RADIATION BY ANTENNAS LOCATED CLOSE TO AN ARBITRARY, SMOOTH, PERFECTLY CONDUCTING, CONVEX SURFACE

In this paper, the uniform geometrical theory of diffraction (UTD) bas ed field expressions developed previously [Pathak et al., 1981] for pr edicting the radiation from antennas which are flush mounted directly on an arbitrary, smooth, perfectly conducting, convex surface are exte nded to allow the antennas to be raised slightly above the convex surf ace. This extension thus allows an efficient ray analysis of many prac tical antenna structures such as blade antennas or pod-mounted antenna s on convex surfaces or even antennas near convex cylindrical masts, e tc. This extended UTD (EUTD) is developed such that it employs the sam e ray paths and retains the same simplicity and efficiency as the earl ier UTD radiation solution [Pathak! et al., 1981]. Furthermore, if the antenna is moved directly onto the surface, then the EUTD solution de veloped here automatically reduces to the earlier UTD solution. Numeri cal results based on EUTD are presented for antennas close to smooth, curved surfaces; in some of these cases, impressed sources of radiatio n are oriented so that they would produce no radiation if they were mo ved directly onto the surface.