Study on Variable Tee and Bridge Tee Attenuators to Enhance IQ Mixer Sideband Suppression in Synthetic Aperture Radar Applications

The IQ mixer is a vital component in developing a synthetic aperture radar system. It needs to maintain its reliable performance, including the ability to suppress un-wanted sidebands in a single sideband modulation process. The sideband suppression performance of the IQ mixer depends on the imbalance of the signal power that meets at the output port. The adjustment of the input power of base chirp signals is required and can be performed by taking advantage of a variable attenuator. A variable attenuator offers practical and efficient use at wide frequencies to reduce the power signal and make two signals equal. This research study focused on variable tee and bridge tee attenuators to enhance IQ mixer sideband suppression in synthetic aperture radar applications. The simulation results show that the tee attenuator offers a high-resolution attenuation at a dynamic range of 1.5 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{dB}$</tex>. It also has a wide range flat response (up to 6 GHz) compared to the bridge tee attenuator.