Maury Microwave offers Measurement and Modeling Device Characterization Systems. One of their technologies is Mixed-signal active load pull which is a unique form of open-loop active load pull. Instead of direct-frequency signal synthesis and analysis, it makes use of RF upconverters and downconverters along with wideband A/D and D/A converters to create and analyze waveforms in baseband.
One of the unique features of mixed-signal approach is that it enables designers to successfully perform load pull with wideband modulated signals, removing the errors caused by impedance-shift and phase-delay over bandwidth. In the past, the modulation bandwidths were small enough that the errors were small and overlooked. With WLAN, WCDMA, 4G and 4G LTE, the modulation bandwidths are large; the errors are large and can no longer be ignored
Another significant advantage of this new technique is the speed at which it can take CW and pulsed-CW load pull measurements. Traditional passive mechanical load pull systems can take hours to perform measurements over a range of impedances and power levels. Maury Microwave’s solution enables the same number of measurements to be taken in seconds or minutes, a time-saving of 20 times to 100 times or more. In fact, some users are measuring up to 1,000 impedance/power states per minute!
An active load pull system enables engineers to cover more of the Smith Chart, giving designers and engineers more details about their transistors and amplifiers.
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