Load Pull Measurements
Load pull is the art of presenting a set of controlled load impedances to a device under test (DUT) while measuring a multitude of parameters at each impedance state. By systematically varying the impedance, it is possible to characterize the performance of a device and design the ideal matching network for optimum realistic large-signal operating conditions.
Vector-receiver load pull, or VNA-based load pull, is a modern and efficient methodology for load pull measurements. Low-loss couplers are placed between the tuners and device-under-test and are connected to the receivers of a VNA, such as a Copper Mountain Technologies’ Cobalt C2420. Doing so allows the a- and b-waves to be measured at the DUT reference plane in real-time, presenting vector information not normally made available through traditional power-meter load pull techniques. Vector-receiver load pull allows the direct measurement of actual impedances presented to the DUT without any assumptions of pre-characterized tuner positioning or losses. The delivered input power is derived from the a- and b-waves with incredible accuracy, which results in properly- defined power added efficiency. Output powers at each frequency, fundamental and multiple harmonics, are made available, as are multi-tone carrier and intermodulation powers. Time-domain NVNA measurements are easily implemented using appropriate hardware.
Copper Mountain Technologies’ VNAs compatible with Maury Microwave Load Pull Solutions include: