Issue link: https://resources.system-analysis.cadence.com/i/1355137
Mitsubishi Electric Cadence is a pivotal leader in electronic design and computational expertise, using its Intelligent System Design strategy to turn design concepts into reality. Cadence customers are the world's most creative and innovative companies, delivering extraordinary electronic products from chips to boards to systems for the most dynamic market applications. www.cadence.com © 2020 Cadence Design Systems, Inc. All rights reserved worldwide. Cadence, the Cadence logo, and the other Cadence marks found at www.cadence.com/go/trademarks are trademarks or registered trademarks of Cadence Design Systems, Inc. All other trademarks are the property of their respective owners. 14720 06/20 DB/SA/SS-M-MSB-MMC/PDF Cadence AWR software provided us with immense benefits for early development of our new 5G power amplifier. Keigo Nakatani, Yutaro Yamaguchi, Yuji Komatsuzaki, and Shintaro Shinjo, Mitsubishi Electric Figure 3 provides the measured and simulated large-signal characteristics of the fabricated GaN Doherty PA MMIC. The fabricated two-stage Doherty PA using a GaN high electron mobility transistor (HEMT) achieved a measured saturation output power of 35.6dBm (3.6W) and peak PAE of 26%. PAE of 23% and 20% was respectively obtained at 6dB and 8dB backoff. Figure 3: Measured and simulated large-signal characteristics of the GaN Doherty PA MMIC Conclusion Because 5G communications is developing rapidly, early delivery of amplifiers to market is critical. The straight- forward, integrated AWR software platform enabled fast development of the GaN PA MMIC while meeting all require- ments and the AWR AXIEM simulator reduced analysis time by 50%. In addition, ready access to a design kit for the Mitsubishi Electric GaN enabled the engineers to optimize the development environment. The design team appreciated that the speed of the circuit and EM simulation was so fast that the AWR AXIEM simulator was able to do the required simulations very quickly and provided highly accurate results. The designers highly recommend AWR software and plan to use it from now on because of its beneficial development environment and simulation speed and accuracy. They were especially appreciative of the design kit support. Solution The design goals for the GaN Doherty PA MMIC were 28GHz operation, 3W saturated output power, and power-added efficiency (PAE) over 20% at 6-8dB backoff output power. The designers chose the AWR Design Environment platform for this exacting design and believe that the resulting Doherty PA device is the state of the art in 5G amplifier devices for the Ka band. The parameters of the Doherty output combiner, which consisted of microstrip lines and metal-insulator-metal (MIM) capacitors on a 50µm thickness SiC substrate, were calculated using AWR Microwave Office circuit design software. EM simulations were performed on the Doherty output combiner using the AWR AXIEM planar EM simulator. The layout and EM simulation are shown in Figure 2. Figure 2: Circuit layout and EM simulation of the Doherty output combiner using AWR AXIEM software