
(a)
The small signal parameters for each of the transistor and the value of the composite transconductance for the given specifications.
(a)

Answer to Problem 11.80P
The value of the small signal parameters are gm2=9.5517 mA/V , rπ2=15.7 kΩ , gm1=448.69 μA/V and the value of the composite transconductance is gCm=8.416 mA/V .
Explanation of Solution
Given:
The given diagram is shown in Figure 1
Figure 1
Calculation:
The expression to determine the value of the emitter current of the second transistor is calculated as,
IE2=IBias2−IBias1=0.50 mA−0.25 mA=0.25 mA
The expression to determine the value of the current IC2 is given by,
IC2=(β1+β)IE2
Substitute 150 for β and 0.25 mA for IE2 in the above equation.
IC2=(1501+150)0.25 mA=248.344 μA
The value of the transconductance gm2 is calculated as,
gm2=IC20.026 V=248.344 μA0.026 V=9.5517 mA/V
The expression to determine the value of the small signal resistance is given by,
rπ2=βgm2
Substitute 150 for β and 9.5517 mA/V for gm in the above equation.
rπ2=1509.5517 mA/V=15.7 kΩ
The value of the drain current ID1 is given by,
ID1=IBias2−IC2=0.50 mA−248.344 μA=251.66 μA
The value of the transconductance gm1 is given by,
gm1=2√KnID1
Substitute 0.2 mA/V2 for kn and 251.66 μA for ID1 in the above equation.
gm1=2√(0.2 mA/V2)(251.66 μA)=448.69 μA/V
The expression to determine the value of the composite transconductance is given by,
gCm=gm1(1+gm2rπ)1+gm1rπ
Substitute 448.69 μA/V for gm1 , 9.5517 mA/V for gm2 and 15.7 kΩ for rπ in the above equation.
gCm=448.69 μA/V(1+(9.5517 mA/V)(15.7 kΩ))1+(448.69 μA/V)15.7 kΩ=8.416 mA/V
Conclusion:
Therefore, the value of the small signal parameters are gm2=9.5517 mA/V , rπ2=15.7 kΩ , gm1=448.69 μA/V and the value of the composite transconductance is gCm=8.416 mA/V .
(b)
The small signal parameters for each of the transistor and the value of the composite transconductance for the given specifications.
(b)

Answer to Problem 11.80P
The value of the small signal parameters are gm2=17.193 mA/V , rπ2=8.724 kΩ , gm1=205.87 μA/V and the value of the composite transconductance is gCm=11.087 mA/V .
Explanation of Solution
Given:
The given diagram is shown in Figure 1
Figure 1
Calculation:
The expression to determine the value of the emitter current of the second transistor is calculated as,
IE2=IBias2−IBias1=0.50 mA−0.05 mA=0.45 mA
The expression to determine the value of the current IC2 is given by,
IC2=(β1+β)IE2
Substitute 150 for β and 0.45 mA for IE2 in the above equation.
IC2=(1501+150)0.45 mA=447.02 μA
The value of the transconductance gm2 is calculated as,
gm2=IC20.026 V=447.02 μA0.026 V=17.193 mA/V
The expression to determine the value of the small signal resistance is given by,
rπ2=βgm
Substitute 150 for β and 17.193 mA/V for gm2 in the above equation.
rπ2=15017.193 mA/V=8.724 kΩ
The value of the drain current ID1 is given by,
ID1=IBias2−IC2=0.50 mA−447.02 μA=52.98 μA
The value of the transconductance gm1 is given by,
gm1=2√KnID1
Substitute 0.2 mA/V2 for kn and 52.98 μA for ID1 in the above equation.
gm1=2√(0.2 mA/V2)(52.98 μA)=205.87 μA/V
The expression to determine the value of the composite transconductance is given by,
gCm=gm1(1+gm2rπ)1+gm1rπ
Substitute 205.87 μA/V for gm1 , 17.193 mA/V for gm2 and 15.7 kΩ for rπ in the above equation.
gCm=205.87 μA/V(1+(17.193 mA/V)(8.724 kΩ))1+(205.87 μA/V)15.7 kΩ=0.0312.796=11.087 mA/V
Conclusion:
Therefore, the value of the small signal parameters are gm2=17.193 mA/V , rπ2=8.724 kΩ , gm1=205.87 μA/V and the value of the composite transconductance is gCm=11.087 mA/V .
Want to see more full solutions like this?
Chapter 11 Solutions
Microelectronics: Circuit Analysis and Design
- Can you rewrite the solution because it is unclear? AM (+) = 8(1+0.5 cos 1000kt +0.5 ros 2000 thts) = cos 10000 πt. 8 cos wat + 4 cos wit + 4 cos Wat coswet. J4000 t j11000rt $14+) = 45 jqooort +4e + e + e j 12000rt. 12000 kt + e +e +e Le jsoort -; goon t te +e Dcw> = 885(W- 100007) + 8 IS (W-10000) - USBarrow_forwardCan you rewrite the solution because it is unclear? Q2 AM ①(+) = 8 (1+0.5 cos 1000πt +0.5 ros 2000kt) $4+) = 45 = *cos 10000 πt. 8 cos wat + 4 cosat + 4 cos Wat coswet. j1000016 +4e -j10000πt j11000Rt j gooort -j 9000 πt + e +e j sooort te +e J11000 t + e te j 12000rt. -J12000 kt + с = 8th S(W- 100007) + 8 IS (W-10000) <&(w) = USB -5-5 -4-5-4 b) Pc 2² = 64 PSB = 42 + 4 2 Pt Pc+ PSB = y = Pe c) Puss = PLSB = = 32 4² = 8 w 32+ 8 = × 100% = 140 (1)³×2×2 31 = 20% x 2 = 3w 302 USB 4.5 5 5.6 6 ms Ac = 4 mi = 0.5 mz Ac = 4 ५ M2 = =0.5arrow_forwardA. Draw the waveform for the following binary sequence using Bipolar RZ, Bipolar NRZ, and Manchester code. Data sequence= (00110100) B. In a binary PCM system, the output signal-to-quantization ratio is to be hold to a minimum of 50 dB. If the message is a single tone with fm-5 kHz. Determine: 1) The number of required levels, and the corresponding output signal-to-quantizing noise ratio. 2) Minimum required system bandwidth.arrow_forward
- Find Io using Mesh analysisarrow_forwardFM station of 100 MHz carrier frequency modulated by a 20 kHz sinusoid with an amplitude of 10 volt, so that the peak frequency deviation is 25 kHz determine: 1) The BW of the FM signal. 2) The approximated BW if the modulating signal amplitude is increased to 50 volt. 3) The approximated BW if the modulating signal frequency is increased by 70%. 4) The amplitude of the modulating signal if the BW is 65 kHz.arrow_forwardAn FDM is used to multiplex two groups of signals using AM-SSB, the first group contains 25 speech signals, each has maximum frequency of 4 kHz, the second group contains 15 music signals, each has maximum frequency of 10 kHz. A guard bandwidth of 500 Hz is used bety each two signals and before the first one. 1. Find the BWmultiplexing 2. Find the BWtransmission if the multiplexing signal is modulated using AM-DSB-LC.arrow_forward
- An FM signal with 75 kHz deviation, has an input signal-to-noise ratio of 18 dB, with a modulating frequency of 15 kHz. 1) Find SNRO at demodulator o/p. 2) Find SNRO at demodulator o/p if AM is used with m=0.3. 3) Compare the performance in case 1) and 2).. Hint: for single tone AM-DSB-LC, SNR₁ = (2m²) (4)arrow_forwardFind Va and Vb using Nodal analysisarrow_forwardCalculate the nodal voltage in the circuitarrow_forward
- Calculate the mesh currents, find Ia, Ib, Ic. Apply mesh analysisarrow_forwardFind Va and Vb using Nodal analysisarrow_forward4. A battery operated sensor transmits to a receiver that is plugged in to a power outlet. The device is continuously operated. The battery is a 3.6 V coin-cell battery with a 245mAHr capacity. The application requires a bit rate of 36 Mbps and an error rate of less than 10^-3. The channel has a center frequency of 2.4 GHz, a bandwidth of 10 MHz and a noise power spectral density of 10^-14 W/Hz. The maximum distance is 36 meters and the losses in the channel attenuates the signal by 0.25 dB/meter. Your company has two families of chips that you can use. An M-ary ASK and an M-ary QAM chip. The have very different power requirements as shown in the table below. The total current for the system is the current required to achieve the desired Eb/No PLUS the current identified below: Hokies PSK Chip Set Operating Current NOT Including the required Eb/No for the application Hokies QAM Chip Set Operating Current NOT Including the required Eb/No for the application Chip ID M-ary Voltage (volts)…arrow_forward
- Introductory Circuit Analysis (13th Edition)Electrical EngineeringISBN:9780133923605Author:Robert L. BoylestadPublisher:PEARSONDelmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage LearningProgrammable Logic ControllersElectrical EngineeringISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education
- Fundamentals of Electric CircuitsElectrical EngineeringISBN:9780078028229Author:Charles K Alexander, Matthew SadikuPublisher:McGraw-Hill EducationElectric Circuits. (11th Edition)Electrical EngineeringISBN:9780134746968Author:James W. Nilsson, Susan RiedelPublisher:PEARSONEngineering ElectromagneticsElectrical EngineeringISBN:9780078028151Author:Hayt, William H. (william Hart), Jr, BUCK, John A.Publisher:Mcgraw-hill Education,





