Multipurpose Radio Frequency (RF) Test Antenna Coupler

A compact antenna testing device is proposed. A Multipurpose RF Test Antenna Coupler is placed over the antenna under test and simulates distant signals incoming at various incidence angles. The proposed device is similar to a radome with an array of active radiating elements embedded inside, or on the surface, of the composite structure. Two methods of exciting the elements will be investigated: 1) Simultaneously excite all elements of the array to produce a steerable plane wave illumination of the antenna under test, 2) Excite only one element at a time which produces spherical wave illumination on the antenna under test. Also two different types of arrays and feed networks will be investigated during Phase I of this program: 1) microstrip fed slots and 2) electrically short dipole elements fed by balanced two-wire feed lines. The feed lines are intentionally mismatched to the radiating elements such that the RF coupler does not disrupt externally impressed incident fields. The results of Phase I is a detailed design which will be ready for fabrication and testing in phase II.