Load Pull Measurements Using SIMULIA IVCAD Suite 4.0

Load Pull is an essential technique for characterizing RF transistors, especially when operating in the nonlinear or large-signal region. S parameters provide valid results only in the linear region, where RF transistors are inefficient and output minimal power.

Load Pull accurately measures devices under real-world, high-power conditions, making it the preferred choice for assessing transistors in RF Power Amplifier applications. When a transistor operates with a large signal, Load Pull is the only reliable method to simulate application-like conditions and predict key RF specifications. By using a software-controlled Load Pull setup, engineers can quickly characterize a Device Under Test (DUT), identify the optimum operating conditions, and design power amplifiers in a fraction of the time, dramatically reducing the design cycle and ensuring maximum performance.

For RF Power Amplifier designs, Load Pull measurements can be performed under Continuous Wave (CW) or Pulsed CW conditions, depending on the DUT power and thermal dissipation. Pulsed CW measurements help mitigate thermal effects, allowing for more accurate assessments of device performance under extreme conditions. The key to effective Load Pull measurements is selecting the right configuration, balancing frequency coverage, power handling, accuracy, and ease of operation to meet specific testing requirements.