Application of hybrid ray/mode theory to microwave links in the presence of atmospheric duct

Fields in an atmospheric elevated duct are derived in terms of combined ray and mode sums. The atmospheric refractive index is modelled by linearised segments of m-profiles. With a line source located within the inversion layer, the fields everywhere are derived in terms of four rays plus a complementary mode sum. Numerical results of space diversity are presented. The present ray/mode theory for field prediction overcomes the drawbacks of either pure ray or pure mode representations