Agilent Measurement Journal - Issue 3 - 2007 - (Page 54)

Comparing measurement examples Two packaged RF GaAs FET switches and one pulsed GSM ampliﬁer were measured to show examples of settling time measurements. In these examples, an Agilent N5242A PNA-X microwave network analyzer was used to measure the settling time and an Agilent 81110A pulse pattern generator was used for the control pulse and PNA hardware trigger (the PNA-X also has internal pulse generators available). Calibrations were performed using a coaxial cal kit. Figure 5a. 0.01 dB settling time of switch using CW time-sweep method at four different RF frequencies Figure 4. Settling time of switch using CW time-sweep method, showing insertion loss (yellow) and input return loss (blue) The CW time-sweep method was used because the ﬁrst switch has a 0.01 dB settling time on the order of tens of milliseconds. Figure 4 shows the settling-time measurement of insertion loss and input return loss. Figure 5a shows the resulting measurements of insertion loss settling time at four different RF frequencies. To measure the different frequencies, the initial setup was copied to three subsequent channels and the CW frequencies modiﬁed in each new channel. Note that the switch still seems to be settling even near the end of the sweep. A longer time sweep was used to investigate this, and 0.001 dB settling times greater than one second were measured as shown in Figure 5b. Surprisingly, a signiﬁcant difference is seen at the selected RF frequencies. This behavior would not have been discovered using the scope method and a DC input. Figure 5b. 0.001 dB settling time of switch using CW time-sweep method at four different RF frequencies The second switch has a 0.01 dB settling time on the order of hundreds of microseconds. Although the PNA-X is capable of performing this measurement in the CW time-sweep mode, the pulsed proﬁle S-parameter method was used for illustration (Figure 6). 54 Agilent Measurement Journal

Table of Contents Feed for the Digital Edition of Agilent Measurement Journal - Issue 3 - 2007

Applying Ingenuity to the Measurement of Emerging Technologies Contents Emerging Innovations Department Delivering Bigger Benefits by Optimizing Customer Workflows Measuring Material Properties at the Nanoscale Utilizing In Situ Atomic Force Microscopy in Life Science, Pharmaceutical and other Bio-Related Applications WiMAX™: Plotting a New Path to Global Mobility Addressing the Triple Complexity of Triple-Play Networks What Next for Mobile Telephony? Exploring the Inner Workings of Tire-Pressure Monitoring Systems Developing, Assessing and Applying a High-Resolution Thin-Film Magnetic Probe Making Accurate Settling-Time Measurements Using a Vector Network Analyzer Applying Metabolomics Methods to the Study of Bacterial Leaf Blight in Rice Plants Measuring Stream Dynamics with Fiber Optics survey

Agilent Measurement Journal - Issue 3 - 2007

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.