Impedance characteristics of a Ka-band MMIC active microstrip antenna using FDTD method

A Ka-band MMIC active microstrip antenna is presented. The whole device consists of a GaAs microwave diode, a coplanar waveguide with an inductive slotted patch resonator, which acts simultaneously as a radioactive coupling aperture of a rectangular microstrip antenna and a microstrip rectangular patch antenna. The impedance characteristics of the antenna have been analyzed by using a direct three-dimensional finite-difference time-domain (FDTD) method. The numerical results for the impedance of the antenna are shown to agree with the measurements.