ADS–CST Co-Simulation and Performance Evaluation of MMIC Power Amplifier for Millimeter-Wave Automotive Radar Applications

Abstract

This paper shows a detailed co-simulation guided design and analysis of a monolithic microwave integrated circuit (MMIC) power amplifier (PA) to be used in millimeter-wave (mmWave) automotive radar with voltage-controlled oscillator (VCO) operating at 76-81GHz band. The suggested technique is comprised of Keysight Advanced Design System (ADS) (nonlinear, circuit-level synthesis) and CST Microwave Studio (full-wave, 3D, electromagnetic (EM) simulations) to help it perform package-aware as well as prove to be layout-accurate. The MMIC PA is realized in 0.15 µm GaAs pHEMT technology and it has a two-stage common-source topology with a high-gain, power-added efficiency (PAE) optimisation. The early-stage design in ADS incorporates load-pull simulation and harmonic balance analysis of the design combined with simulation in CST to model the EM effects due to layout parasitics, ground discontinuities and interconnects. Co-simulation output performance shows small-signal gain peaking at 21 dB at 77 GHz, having a saturated output of +18.2 dBm as well as a peak PAE of 32% all with equally good input and output matching (S11 < -10 dB). The amplifier has realistic substrate and bias conditions and remains thermally stable and electromagnetically sound. The co-design method minimizes the differences between schematic and fabricated performance which facilitates reduced prototyping time and lead time and the robustness of the design. This research emphasizes that EM-circuit co-simulation plays a very crucial role in mmWave MMIC design and determines a proven approach to the design of high-performance compact power amplifiers in new generation vehicles radar and 6G communications applications.