Performance and analysis of an aluminium nitride isolation resistor

An essential requirement of optimised microwave resistor operation is good thermal loss. In this application the thermal conductivity of the ceramic substrate base is as important as its complex permittivity. A good thermally conducting aluminium nitride resistor has been constructed for beamformer isolation purposes in corporate feed networks. Its microwave performance has been measured and found to be in good agreement with that of a conventional alumina package. An efficient and flexible quasi-static finite-element solver is also developed to model this class of structure. Numerical calculations accurately predict impedance measurements for both types of resistor. Stripline power divider measurements are included for completeness