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Unformatted text preview: impedance that would result from this error. (5 Marks) Question 2) A vector voltmeter measurement set‐up, shown in figure 3, is used to measure an unknown load. The system uses 50‐ohm components (i.e. the characteristic impedance of the system is 50 ohms). The RF generator is operating at 800 MHz, you may assume that the source is matched to the system. After calibration, an unknown load is attached and readings are performed. The forward coupling coefficient is 9.9 dB at this frequency, while the backward coupling coefficient is 10.1 dB at this frequency. Channel A voltage is set to 0 dB, (for both the calibration and the measurement operations), and channel B voltage (the backward channel) has a voltage of ‐4.15 dB with a phase of 29.79 degrees relative to channel A. Justify all of your answers. (20 Marks) Figure 3 Vector Voltmeter measurement system a) Compute the load impedance. (10 Marks) b) Determine the effect of changing the 50 ohm terminations on the directional coupler to short circuit loads would change the power dissipated by the VV. What percentage of the coupled power would reach the voltmet...
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- Fall '10