Ampleon Optimizes Radio Frequency Power with Multiphysics Simulation to Meet Cost and Performance Goals

For nearly 60 years, Dutch semiconductor company Ampleon has specialized in radio frequency (RF) power products, which are decreasing in size while increasing in complexity. The company’s vision is to advance society through innovative RF solutions, such as discrete devices, monolithic microwave integrated circuits (MMICs), laterally diffused metal-oxide semiconductor (LDMOS) technology, and gallium nitride (GaN) devices. 

Challenges

With such a wide array of offerings, the application frequencies span from a few tens of megahertz for broadcast applications to several gigahertz for the 4G and 5G infrastructure markets. Depending on the application, these products range from a few watts to kilowatt output power levels.

To achieve these power levels, multiple large dies are combined in a single package. These dies can be single transistors as well as integrated MMIC amplifiers. They are combined with other components like large metal-oxide MOS capacitors, which are also included in the package. The purpose of these components is to provide in-package impedance transformation and matching. The dies and the additional components are connected via bond wires, which are also used to connect the dies to the package leads and, thus, to external parts.

These bond wires not only serve the purpose of connection — they are design elements that are part of the impedance transformation and matching. As such, accurate prediction of their multiphysics behavior and their interaction with the dies and package leads are key challenges for optimizing device performance.

Moreover, the need to reduce sizes requires packing many components into a limited space, leading to increased temperatures. Making sure that high temperatures and related mechanical stress levels remain under reliability limits is challenging. 

Engineering Solutions

Ampleon engineers use the Ansys Electronics Desktop platform for EM, thermal, and mechanical simulations to analyze and optimize the EM performance of packaged and integrated devices as well as complete systems under real-life operating conditions. It is also used for electro-thermo-mechanical multiphysics integrated flow, in which the dissipations calculated by the EM solver are used as loads by the thermal solver. Those results are, in turn, used as loads by the mechanical solver. EM-circuit co-simulations are sometimes also used to account for realistic loading and operating conditions.

Ampleon engineers also use Ansys structural simulation solutions when more sophisticated material or simulation models are required. In these cases, the integration is via the Workbench interface. The Workbench platform enables Ampleon engineers to feed mechanical simulation results back to the EM solver and calculate the effect of the thermally induced deformations on the EM performance of their products.

Ampleon enigneers use Icepak software to investigate and optimize cooling methodologies at the package, board, and system levels, and they utilize RaptorX software to optimize the EM performance of advanced MMIC products.