1. An amplifier has noise equivalent bandwidth of 15 kHz. When a 10 k resistor at 300 K is connected to the input, determine the thermal noise voltage of the amplifier by assuming the meter is impedance matched to the amplifier. 2. An amplifier is quoted as having a noise figure 3.5 dB. Calculate the noise factor, noise temperature and noise power. 3. Determine the overall noise factor and noise figure for three cascaded amplifiers as shown in figure below. Amplifier 1 G-10dB NF-4dB Amplifier 2 G-10dB NF2=8dB Amplifier 3 G3=20dB NF3=10dB 4. Calculate the equivalent noise temperature of a microwave amplifier with an average noise power of 1x10-14 W and operating bandwidth of 25 MHz. 5. An amplifier consists of three identical stages in tandem. Each stage having equal input and output impedances. For each stage, the power gain is 5 dB when correctly matched. Calculate the overall power gain. 6. For a non-ideal amplifier with the parameters as shown in Table 1, determine: Input Signal-to-Noise ratio (dB). Output Signal-to-Noise ratio (dB). Noise factor and noise figure. Equivalent noise temperature. a. b. C. d. Table 1: Non-ideal amplifier parameters. 2.5 x 10-10 W 3 x 10-18 W Input signal power Input noise power Power gain Internal noise (Na) 1,000,000 4.5 x 10-12 W