Matched loads using substrate integrated waveguide and shaped absorbing material for KA‐/Q‐band applications

ABSTRACT Two planar matched loads using substrate integrated waveguide (SIW) and absorbing material are presented. The magnetic‐loss absorbing material is cut into horn and concave shapes and loaded into SIW sections respectively to form two SIW matched loads. Measured results of the proposed SIW matched loads show comparable agreement with their corresponding simulations. Moreover, the proposed matched loads exhibit fractional bandwidths of 46.1 and 68%, respectively with a return loss over 18.5 dB, as well as system integration capability, low complexity and low cost, which demonstrate their suitability for Ka‐ and Q‐band applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1174–1178, 2017