Microwave Devices
Questions & Answers
1. If a signal has a gain (G) equals to 32000 (linear), what is the gain in dB? How much will be the remaining power (in %), if the gain is reduced to 6dB.
4. An amplifier has an input power of 0.5 watts and its output power of 75 watts. What is the gain of the amplifier in dB?
5. Calculate the length of a quarter-wave transmission line where frequency is 1800 MHz.
7. Calculate the gain of the antenna (in dB) if the radiation resistance of the antenna is 52 £2, and loss resistance is 12 2. The antenna directivity is 18 (linear).
8. Calculate the radiation resistance when the loss resistance of an antenna is 82, the directivity of the antenna is 20 (linear) and power gain is 18 (linear).
10. Calculate the reflection coefficient || when the antenna load impedance is Z₁ = (30 + j 40), and characteristic impedance is Z. = 50 Ω.
11. Calculate the reflection coefficient when the VSWR= 1.5. Also calculate the corresponding return loss in dB.
In the figure 1 given below,determine the frequency rangewhere the antenna efficiency is above 80%.And state the frequencywhere antenna gain is maximum in the plot.一-.E重k起成y70如2241o9达yGlu)Figurel:Gain and efficiency vs.frequency plot.
In the figure 2, simulated and measured S11 plots of an antenna designed are given. 1. Simulated
14. Plot the following impedance points on smith chart. i. Z1= 100+j50 ii. Z2 = 75-j100 iii. Z3 = j200 iv. Z4 = 150
15. Plot the following on smith chart i. Z5 = infinity (Open circuit) ii. Z6 = 0 (short circuit) iii. Z7 = 50 (Z.) iv. Z8 = 184-j900
EXPERIMENT 5 • Measurement of Impedance (Use component #507 - termination - as an additional load): Please do the following: 1. Record all your work in your individual lab notebook in an orderly fashion. 2. Write a group formal report in which all group/team members participate fully. Use the formal lab report format provided! Your report must address all the questions, objectives, etc. in the handout. Please DO NOT forget RESULTS and CONCLUSIONS!
