Millimetre-wave hybrid dielectric-microstrip antenna array

The new concept of using dielectric guides as a replacement for microstrip lines in linear microstrip arrays is conceived as a means of reducing the antenna dissipative loss, while retaining many of the attractive manufacturing and operational advantages of printed arrays. This hybrid microstrip-dielectric array takes the form of an insular guide to which the microstrip elements are to be coupled. Precise field representations for the insular guide enable design data for dissipative losses and element coupling to be analysed, principally for the Ey11 and Ex21 insular guide modes. For ease of manufacture and good coupling control, the microstrip elements take the form of proximity coupled resonant patch antennas, and measurements at both millimetre wavelengths and on microwave scaled models substantiate analytical results throughout. A 40-element travelling-wave hybrid array is designed illustrating the reduction in dissipative losses, the sensitivity to dimensional tolerances and the compatibility of the hybrid antenna concept with dielectric, as opposed to conventional metal, waveguide transmitter/receiver circuits.