X-Band Substrate Integrated Waveguide Amplifier

Design and realization of a compact X-band single-transistor amplifier with substrate integrated waveguide (SIW)-based input and output matching networks is presented. The overall size of the proposed SIW amplifier is only 1.5lambda
_g
at the center frequency. Using a calibration technique, we extract the
S
-parameters of the fabricated amplifier with reference to its SIW ports. Measurements show that the amplifier features 10 dB of power gain with less than 2 dB of ripple and more than 10 dB of input and output return losses on the SIW ports in the entire frequency band. Due to an appropriate modeling of the constituent blocks of the amplifier, a good agreement between the simulation and measurement results is observed.