第六章 微波网络参量及网络分析仪.ppt

1-* Slide 99 This slide shows the decrease in the number of connections needed to fully calibrate the multiport test systems using Test Set Cal. 1-* Slide 100 Agilent has test sets that are specifically meant to work with the PNA Series of network analyzers, for the ultimate in measurement accuracy, speed, and convenience. The test sets are controlled by a Visual Basic program that runs internally in the network analyzer. The HO3 features solid-state switching, and is aimed at duplexer testing. The H08 uses mechanical switches, and is suitable for low-volume manufacturing of base-station components. Other test sets with different port arrangements can be configured as well. 1-* Slide 67 A feature contained in many of Agilents T/R-based network analyzers is the enhanced response calibration. This calibration greatly reduces all the error terms involving a reflection from the source match. It requires the measurement of short, open, load, and through standards for transmission measurements. Essentially, it combines a one-port cal and a response cal to correct source match during transmission measurements. Recall that a standard response calibration cannot correct for the source and load match error terms. Continuing with our filter example, we see the enhanced response calibration has improved the effective source match during transmission measurements to around 35 dB, instead of the 14 dB we used previously. This greatly reduces the calibration error (± 0.02 dB instead of ± 0.22 dB), as well as the two measurement error terms that involve interaction with the effective source match. Our total measurement error is now ± 0.24 dB, instead of the previously calculated ± 0.85 dB. 1-* Slide 68 We can further improve transmission measurements by using the enhanced response calibration and by inserting a high-quality attenuator between the output port of the device and test port two of the network analyzer. In this example, we will use a 10 dB attenuator with a SWR of 1.