A Review of Millimeter-wave InP Distributed Amplifiers

This article reviews millimeter-wave Indium Phosphide (InP) distributed amplifiers (DAs) developments, focusing on high power, high linearity, and design techniques for high gain and wide-band performance. A triple stacked Heterojunction Bipolar Transistor (HBT) topology is used to design a high-power DA with an output saturated power (Psat) of 19.5 dBm. Additionally, a double-stacked HBT topology with 3D interdigital capacitors is used to extend the bandwidth up to 160 GHz. Moreover, a linearization technique using intermodulation feedforward is also employed in a DA, yielding 5-7 dB improvement in the output third-order intercept point (OIP3). Finally, a gain enhancement technique via inductive/capacitive feedback is used in a bandpass DA, demonstrating a 4-dB improvement in gain over 78 GHz bandwidth compared to the conventional DA. All the proposed DAs are tested and characterized to verify the design concepts.