A 208 GHz InP Distributed Amplifier with Combining Loss Reduction Techniques

This paper introduces a wideband distributed amplifier (DA) using Indium Phosphide (InP) heterojunction bipolar transistor (HBT) technology that achieves a 208 GHz bandwidth. The DA comprises eight uniform gain cells, each employing a triple-stacked topology with capacitive coupling and resistive/capacitive degeneration techniques to reduce input capacitance and minimize input transmission line loss at high frequencies. The DA delivers an average gain of 11 dB and a maximum saturated output power (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{P}_{\text{sat }}$</tex>) of 14.6 dBm, while maintaining an average <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{\text{sat }}$</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1 3. 6 ~ d B m}$</tex> up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1 7 5 ~ G H z}$</tex>. It also achieves a maximum 1 dB gain compression power (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{P}_{1 \text{dB}}$</tex>) of 10.7 dBm, with an average <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P_{1 \text{dB}}$</tex> of 9.3 dBm.