Amplitude/Phase Temperature Compensation Attenuators With Variable-$Q$ FET Resonators

Amplitude/phase temperature compensation attenuators have been developed. The circuits are based on new variable-$Q$ field-effect transistor resonators. By employing the configuration, the dynamic range of the attenuation and the phase-shift can be flexibly determined. To verify this methodology, we have fabricated a low phase-shift temperature compensation attenuator and an amplitude/phase temperature compensation attenuator with monolithic microwave integrated circuit technology. The low phase-shift circuit achieved an attenuation dynamic range of 16.9 dB, a phase shift of ${\pm {\hbox{5.2}}}^{\circ}$, and a minimum insertion loss of 4.5 dB in $X$-band over 75 $^{\circ}{\hbox{C}}$ temperature variation. The amplitude/phase compensation circuit achieved an attenuation dynamic range of 11.7 dB, a phase shift of ${+ {\hbox{37}}}^{\circ}$, and a minimum insertion loss of 4.9 dB in $X$-band over 75 $\ ^{\circ}{\hbox{C}}$ temperature variation.