Dream Catcher ME3000 Analog Electronics Lab 6 User manual

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ME3000 Analog Electronics Lab 6 - 1/19
ME3000 Analog Electronics
Lab 6
RF Class A Tuned Amplifiers
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For further information, see the Courseware Product License Agreement.
Objectives
i) To demonstrate the practical issues of designing an RF tuned amplifier
ii) To demonstrate AC measurements on a Class A amplifier
Equipment Required
i) ME3000-M2 Analog Electronics Training Kit
ii) Digital Multimeter, recommendation : Agilent 34405A or U2741A
iii) 50 MHz Oscilloscope or equivalent, recommendation : Agilent DSO1002A 60 MHz or
U2701A
iv) 10 MHz Function Generator or equivalent, recommendation : Agilent 33220A or U2761A
v) Dual Output (+/- 12V, 0.5A) DC Power Supply, recommendation : Agilent E3631A
Accessories Required
i) 1 x 4-way power supply cable
ii) 1 x BNC(m)-to-grabber clips coaxial cable
iii) 6 x jumper cables terminated with grabber clips at both ends
iv) 1 x antistatic wrist strap
Caution:
An electrostatic discharge generated by a person or an object coming in contact with electrical
components may damage or destroy the training kit. To avoid the risk of electrostatic discharge,
please wear the antistatic wrist strap and observe the handling precautions and recommendations
contained in the EN100015-1 standard. Do not connect or disconnect the device while it is being
energized.

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ME3000 Analog Electronics Lab 6 - 2/19
1. Introduction
A Class A transistor amplifier is biased so that the transistor conducts continuously. The transistor of
the Class A amplifier is biased in the active region during the whole duration of operation. The Class A
amplifier is a linear amplifier since the transistor operation in the active region is almost linear. Two
types of amplifiers can be designed – tuned and untuned amplifiers. An untuned amplifier has a wider
bandwidth than a tuned amplifier, as shown in Figure 1.
A tuned amplifier consists of a resonance network as illustrated in Figure 2. It includes a parallel RLC
tank circuit. This circuit will experience high impedance and maximum voltage gain at the resonance
frequency. The resonance frequency can be calculated by LC fo
 2
1
.
R C L
Untuned amplifier
frequency response
Tuned amplifier
frequency response
Voltage
gain
Figure 1 – Class A Amplifier Frequency Response
Figure 2 – RLC Tank Circuit Schematic Diagram
Frequency

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ME3000 Analog Electronics Lab 6 - 3/19
A radio frequency (RF) amplifier is designed to operate in the RF region which normally refers to
frequencies between 1 MHz to 300 MHz. Great care must be taken in designing an RF amplifier as
most of the components will not portray ideal characteristics at radio frequencies. Most of the RF
Class A amplifiers are tuned amplifiers to obtain higher voltage gain and be less susceptible to noise.
A typical RF Class A tuned amplifier is shown in Figure 3.
Vcc
Q
CC
C2
L
RB2
RE
C1
RB1
Input
Output
Figure 3 – Typical Class A Tuned Amplifier Schematic Diagram

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ME3000 Analog Electronics Lab 6 - 4/19
2. DC Biasing
1. Locate the Class A Tuned Amplifier section on the ME3000-M1 training kit.
2. Disconnect all the jumpers located in the Class A Tuned Amplifier section.
3. Construct an RF Class A amplifier circuit shown in Figure 4 by connecting jumpers to J28 and
J29.
4. Connect the power supply to the training kit using the 4-way power supply cable. Set the
power supply voltage to +15 V. Turn on the power supply. Refer to Appendix for details.
5. Use the multimeter to measure VCC applied to the transistor (between terminals TP4 and
GND). Calculate the voltage at the transistor base using the resistive voltage divider formula,
CCB V
RR
R
V
1716
17

, where R17 = 4.7k and R16 = 10k. Then, calculate the voltage at the
transistor emitter, VE using VE = VB – 0.7.
6. Measure VC (at TP2 and GND), VB (at TP3 and GND), and VE (at TP5 and GND) on the
transistor C, B, E pins.
7. Verify that VB – VE ≈ 0.7 V.
8. Check if the calculated VB and VE values agree with the measured values.
9. Estimate IC using
E
E
EC R
V
II  , where RE = R18 = 150 .
10. Determine the transconductance, gm of the transistor at T = 25 using
26
)(mAI
gC
m.
Vcc
Q3
C7
C8
L1
R17
R18
C6
R16
Input
Output
C10
R19
Figure 4 – Schematic Diagram of DC Biasing on an RF Class A Amplifier

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ME3000 Analog Electronics Lab 6 - 5/19
3. Frequency Response
11. Set the function generator output to 40 mVpp.
12. Connect the function generator output to TP1 and reference to GND using the BNC-to-
grabber clips coaxial cable.
13. Connect the oscilloscope CH1 probe to TP1 and GND.
14. Connect the oscilloscope CH2 probe to TP6 and GND.
15. Set the trigger signal to CH1.
16. Sweep the function generator frequency from 2 MHz to 8 MHz in 100 kHz increments.
17. Record the peak-to-peak voltage at the input (CH 1) and output (CH 2), and determine the
magnitude of the voltage gain, AV as a function of frequency.
18. Plot the AV versus frequency curve and estimate the resonance frequency of the amplifier
from the curve. The input and output waveforms should be approximately 180 out of phase
during resonance. The voltage gain, AV is at its maximum when resonance occur, with the
theoretical resonance frequency given as LC fo
 2
1
, where L = 4.7 H and C = 100 pF.
19. Use the calculated AV at resonance to estimate the value of rCE using










m
V
m
V
L
L
ceLcemV g
A
g
A
R
R
rRrgA )||( .
20. Calculate the early voltage, VA of the transistor using
C
A
ce I
V
r.

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ME3000 Analog Electronics Lab 6 - 6/19
4. Voltage Gain Estimation
21. Unplug the jumpers from J28 and J29.
22. Set RL = 470  by connecting jumpers to J30 and J31.
23. Set the function generator output to 40 mVpp and the output frequency to the resonance
frequency value measured earlier.
24. Connect the function generator output to TP1 and reference to GND.
25. Connect the oscilloscope CH1 to TP1 and GND.
26. Connect the oscilloscope CH2 to TP6 and GND.
27. Set the trigger signal to CH1.
28. Record the peak-to-peak voltage at the input (CH 1) and output (CH 2), and determine the
magnitude of the voltage gain, AV.
29. Determine the amplifier voltage gain using )||( LcemV RrgA  and the rce and gm values
calculated earlier. Compare the calculated value with the value measured in step 28.
30. Repeat steps 28 and 29 for RL = 1470  by unplugging the jumpers from J30 and J31 and
connecting the jumpers to J28 and J32.
31. Turn off the power supply and disconnect all the cables from the Class A Tuned Amplifier
section.

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ME3000 Analog Electronics Lab 6 - 7/19
Appendix: Tips on Using Agilent E3631A Triple
Output DC Power Supply
Supplying +5 V, +15 V, and 15 V to the ME3000-M1 training kit:
 Press Power to turn on the E3631A.
The E3631A has three adjustable output supplies namely +6 V, +25 V, and 25 V. By default,
all outputs are disabled (the OFF annunciator is turned on), the +6 V supply is selected, and
the knob is ready for voltage control.
 Adjust the knob to +5 V.
 Press Display Limit and set the current limit to 0.5 A.
 Next, set the supply to +25 V (positive supply). Set the voltage to +15 V and current limit to
0.5 A. Repeat the same procedure for –25 V (negative supply) to set the voltage to 15 V and
current limit to 0.5 A.
 Connect the E3631A to the ME3000 training kit as shown below.
 Enable the power supply outputs by pressing Output On/Off. The CV and +25 V
annunciators should turn on.
 Caution: If the CC annunciator is turned on, disable the output and check whether this is due
to the current limit setting or faulty connection.
 Upon completion of each experiment and before making any connection on the training kit,
ensure that the power supply output is disabled by pressing Output On/Off.
ME3000-M1 Training Kit
Power Supply
(E3631A)
com
–
+

25 V
6 V
–
+
4-way
connector

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ME3000 Analog Electronics Lab 6 - 8/19
Appendix: Tips on How to Use the Agilent U2741A
USB Modular Digital Multimeter
Front Panel of the Agilent U2741A USB Modular Digital Multimeter
Figure B-1 – Front Panel of the Digital Multimeter
Setting Up the Connection
1. Connect the digital multimeter to the PC using a USB cable.
2. Power on the digital multimeter.
3. Launch the Agilent IO Control and the Agilent Measurement Manager (AMM).
4. The Select USB Device dialog box will appear displaying the connected U2741A devices. To
start the application, select a U2741A device and click OK to establish the connection
5. The U2741A can only be operated via the USB interface. On the front panel of the U2741A,
there are two LED indicators. The power indicator lights up once the U2741A is powered on.
There is a system error if the indicator blinks after the U2741A is powered on. The USB
indicator will only blink when there is data exchange activity between the U2741A and the PC.
6. You can control the U2741A via the Agilent Measurement Manager (AMM) for U2741A or
via SCPI commands sent through the USB interface from your own application programs.
7. Launch the Agilent IO Control and AMM.
8. The Select USB Device dialog box will appear displaying the connected U2741A devices. To
start the application, select a U2741A device and click OK to establish the connection. You
may start to use the digital multimeter now.
Measuring DC Voltage
1. The DC voltage measurement function of the U2741A has the following features:
 five ranges to select: 100 mV, 1 V, 10 V, 100 V, and 300 V; or auto range
 input impedance is 10 MΩ for all ranges (typical)
 input protection is 300 V on all ranges (HI terminal)

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ME3000 Analog Electronics Lab 6 - 9/19
2. Make the connection as shown in Figure B-2 in order to measure DC voltage. You can
control the U2741A via the Agilent Measurement Manager (AMM) software for U2741A or
via SCPI commands sent through the USB interface from your own application programs.
Figure B-2 – Measuring DC Voltage
3. If you are using the AMM, select the DCV function located at the top-left corner. Set the
desired range under Range section. A suitable range should be selected to give the best
measurement resolution. The reading is displayed and updated continuously.
4. If you are using SCPI commands, enter MEASure[:VOLTage]:DC? in order to make a DC
voltage measurement.
Measuring DC Current
1. The DC current measurement function of the U2741A has the following features:
 three ranges to select: 10 mA, 100 mA, 1 A, and 2 A; or auto range
 input impedance is 10 MΩ for all ranges (typical)
 input protection fuse is 2 A, voltage rating 250 V on all ranges
2. Make the connection as shown in Figure in order to measure DC current. You can control
the U2741A via the Agilent Measurement Manager (AMM) software for U2741A or via SCPI
commands sent through the USB interface from your own application programs.
Figure B-3 – Measuring DC Current
3. If you are using the AMM, select the DCI function located at the top-left corner. Set the
desired range under the Range section. A suitable range should be selected to give the best
measurement resolution. The reading is displayed and updated continuously.
4. If you are using SCPI commands, enter MEASure:CURRent[:DC]? in order to make a DC
current measurement.

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ME3000 Analog Electronics Lab 6 - 10/19
Appendix: Tips on How to Use the Agilent
U2761A USB Modular Function Generator
Front Panel of the Agilent U2761A USB Modular Function Generator
Figure A-1 – Front Panel of the U2761A
Setup Connection
9. Connect the function generator to the PC using a USB cable.
10. Power on the function generator.
11. Launch the Agilent IO Control and the Agilent Measurement Manager (AMM).
12. The Select USB Device dialog box will appear displaying the connected U2761A devices. To
start the application, select a U2761A device and click OK to establish the connection.
13. Click Output to enable or disable the output of the function generator after the desired
parameters are set.
14. The U2761A is able to output five standard waveforms that are Sine, Square, Ramp,
Triangle, Pulse, and DC.
15. You can select one of the three built-in Arbitrary waveforms or create your own custom
waveforms.
16. You can also internally modulate Sine, Square, Ramp, Triangle, and Arbitrary waveforms
using AM, FM, PM, FSK, PSK, or ASK.
17. The linear or logarithmic frequency sweeping is available for Sine, Square, Ramp, Triangle,
and Arbitrary waveforms.
18. Table A- shows which output functions are allowed with modulation and sweep.
19. Each √ indicates a valid combination. If you change to a function that is not applicable for
modulation, or sweep; then the modulation or mode will be disabled.
Table A-1 – Output Functions
Sine Square Ramp Triangle Pulse DC Arbitrary
AM, FM, PM, FSK, PSK, ASK Carrier √ √ √ √ √
AM, FM, PM Internal Modulation √ √ √ √ √
FSK, PSK, ASK Internal Modulation √
Sweep Mode √ √ √ √ √

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ME3000 Analog Electronics Lab 6 - 11/19
Agilent Measurement Manager Soft Front Panel (Function Generator)
Figure A-2 – Graphic User Interface of the Agilent Measurement Manager (Function Generator)
Figure A-2 shows the graphic user interface of the Agilent Modular Function Generator under the
Agilent Measurement Manager (AMM). Table A- shows the features of each panel of the interface.
Table A-2 – Features of the AMM Function Generator Interface
No. Panel Features
1 Waveform Pattern Selection Select various types of output function by clicking the buttons.
2 Waveform Parameters Configure the function parameters (Frequency, Amplitude, and Offset)
3 Waveform Pattern Display Display a graph representation of the output function
4 Modes of Waveform Configure to modulation mode or sweep mode
5 Status Display Display the parameters and status of the configured output waveform
6 Trigger & Output
Enable/Disable
Enable/disable the Trigger and Output buttons (they are highlighted
when enabled and grey when disabled)

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ME3000 Analog Electronics Lab 6 - 12/19
Function Limitation
If you change to a function where the maximum frequency is less than the current function, the
frequency will be adjusted to the maximum value for the new function. For example, if you are
currently outputting a 20 MHz sine wave and then change to the Ramp function, the U2761A will
automatically adjust the output frequency to 200 kHz (the upper limit for Ramp). As shown in Table A-
, the output frequency range depends on the function currently selected. The default frequency is 1
kHz for all functions.
Table A-3 – Output Frequency Range
Function Minimum Frequency Maximum Frequency
Sine 1 µHz 20 MHz
Square 1 µHz 20 MHz
Ramp, Triangle 1 µHz 200 MHz
Pulse 500 µHz 5 MHz
DC Not applicable Not applicable
Arbitrary 1 µHz 200 kHz
2 MHz (U2761A Option 801)
Amplitude Limitation
The default amplitude is 1 Vpp (into 50 Ω) for all functions. If you change to a function where the
maximum amplitude is less than the current function, the amplitude will automatically adjust to the
maximum value for the new function. This may occur when the output units are Vrms or dBm due to
the differences in crest factor for the various output functions. For example, if you output a 2.5 Vrms
Square wave (into 50 Ω) and then change to the Sine wave function, the U2761A will automatically
be adjusted the output amplitude to 1.768 Vrms (the upper limit for Sine wave in Vrms).
Duty Cycle Limitations
For Square waveforms, the U2761A may not be able to use the full range of duty cycle values at
higher frequencies as shown below:
 20% to 80% (frequency 10 MHz)
 40% to 60% (frequency 10 MHz)
If you change to a frequency that cannot produce the current duty cycle, the duty cycle is
automatically adjusted to the maximum value for the new frequency. For example, if you currently
have the duty cycle set to 70% and then change the frequency to 12 MHz, the U2761A will
automatically adjusts the duty cycle to 60% (the upper limit for this frequency).
Output Termination
This configuration applies to output amplitude and offset voltage only. The U2761A has a fixed series
output impedance of 50 Ω to the device output connector. If the actual load impedance is different
from the specified value, the amplitude and offset levels will be incorrect.
 The range of the output termination is 1 Ω to 10 kΩ, or Infinite. The default value is 50 Ω.
 The output termination setting is stored in volatile memory and upon power-off or after a
remote interface reset, the setting will return to a default value.
 If you specify a 50 Ω termination but are actually terminating into an open circuit, the actual
output will be twice the value specified. For example, if you set the offset to 100 mVDC (and
specify a 50 Ω load) but are terminating the output into an open circuit, the actual offset will
be 200 mVDC.
 If you change the output termination setting, the output amplitude and offset levels are
automatically adjusted (no error will be generated). For example, if you set the amplitude to 5
Vpp and then change the output termination from 50 Ω to high impedance, the amplitude

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ME3000 Analog Electronics Lab 6 - 13/19
value will double to 10 Vpp. If you change from high impedance to 50 Ω, the displayed
amplitude value will drop to half.
 You cannot specify the output amplitude in dBm if the output termination is currently set to
high impedance. The units are automatically converted to Vpp.
You may configure the output termination by clicking Tools in the menu bar. Select Waveform Gen
followed by the Output Setup tab; input the desired load impedance value on the Impedance Load
panel, and select the unit from the drop down list; or select High Z for high impedance load.

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ME3000 Analog Electronics Lab 6 - 14/19
Appendix: Tips on How to Use the Agilent U2701A
USB Modular Oscilloscope
Front Panel of the Agilent U2701A USB Modular Oscilloscope
Figure B-1 – Front Panel of the U2701A
Setup Connection
1. Connect the oscilloscope to the PC using a USB cable.
2. Power on the oscilloscope.
3. Launch the Agilent IO Control and the Agilent Measurement Manager (AMM).
4. The Select USB Device dialog box will appear displaying the connected U2701A devices. To
start the application, select a U2701A device and click OK to establish the connection.
5. Figure B-2 shows the general graphical user interface of the Agilent Modular Oscilloscope on
the Agilent Measurement Manager.
Figure B-2 – Graphical User Interface of the Agilent Measurement Manager (Oscilloscope)

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ME3000 Analog Electronics Lab 6 - 15/19
Agilent Measurement Manager Soft Front Panel (Oscilloscope)
Figure B-35 – Soft Front Panel of the Oscilloscope
Figure B-35B-3 shows the graphic user interface of Agilent Modular Oscilloscope under Agilent
Measurement Manager together with the label of each panel. Table B-1B-1 shows the features of
each panel of the interface.
Table B-1 – Features of the AMM Oscilloscope Interface
No. Panel Description
1 Oscilloscope toolbar Consists of oscilloscope tools
2 Waveform Acquisition tab Displays the time-domain waveform for the oscilloscope
3 FFT Analysis tab Displays the FFT spectrum of the signal
4 Configuration summary Displays the configured functions and settings
5 Waveform graph display Displays the output of the data acquired
6 Scope control tabs Consists of all the sub functions of the oscilloscope
7 Measurement Results panel Displays the measurement results of the scope operations
8 Status tab Displays the status panel, which shows the history of operations
9 Refresh rate Displays the graph update rate in frame/sec.
10 Video Sampling Rate Displays the video sampling rate (in number of samples per second taken from a
continuous signal)
11 Calibration Delta Temp.
indicator Displays the calibration delta temperature of the connected device
Analog Controls

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ME3000 Analog Electronics Lab 6 - 16/19
The analog control panel of the interface consists of a vertical control and a horizontal control that are
used to control and set the waveform of the graph display. The vertical control is used to change the
vertical scale and position of the waveform. The soft front panel of the vertical system control is shown
in Figure .
Figure B-4 – Soft Front Panel of the Vertical System Control
1. To display waveform from channel 1 / channel 2, click 1 / 2 or press the shortcut key F5 / F6.
2. To toggle the channel on or off, click the channel buttons on the vertical control panel or click
the toolbar to toggle the channel on or off, as shown below.
Figure B-56 – Channel On/Off Mode
3. The channel options provide four types of adjustment to the channel waveform; these options
are AC Coupling, Invert, BW Limit, and Attenuation (1X, 10X, 100X). You may click the
button as shown in Figure to set the channel options.
Figure B-6 – Channel Options
4. The Volt/Div control sets the sensitivity of the channel. You can select the channel sensitivity
from the drop-down list.
5. You can also use the button or button to increase or decrease the sensitivity of
both channel 1 and channel 2.

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ME3000 Analog Electronics Lab 6 - 17/19
6. You can also configure the offset of the oscilloscope by using the offset control as shown in
Figure . The offset is used to configure the position of the ground relative to the center of the
display.
Figure B-7 – Soft Front Panel of the Offset Control
7. The oscilloscope shows the time per division in the scale readout. As all waveforms use the
same time base, the oscilloscope only displays one value for all channels.
8. The horizontal controls allow you to adjust the horizontal scale and position of waveforms.
The horizontal center of the screen is the time reference for waveforms. Changing the
horizontal scale causes the waveform to expand or contract in the center of the screen. It
provides functions of Time Base, Delay, and Mode for the horizontal scale adjustment. This
is shown in Figure B-87.
Figure B-87 – Soft Front Panel of the Horizontal System Controls
9. Time base allows you to control how often the values are digitized. The soft front panel of the
time-base control is shown in Figure B-98.
Figure B-98 – Soft Front Panel of the Time-Base Control
10. You may click or to increase or decrease the horizontal sweep speed.
11. Select the time base from the drop-down list to adjust the horizontal sweep speed.
12. Delay setting allows you to set the specific location of the trigger event with respect to the
time reference position. When the delay time knob is turned, the trigger point will move to the
left or right of the waveform graph display. You may adjust the delay time to change the
trigger point. This is shown in Figure .

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ME3000 Analog Electronics Lab 6 - 18/19
Figure B-10 – Soft Front Panel of the Delay Control and Trigger Point
13. You may click or to increase or decrease the delay time.
14. The oscilloscope offers three types of horizontal mode functions, which are Main Mode, Roll
Mode, and XY Mode. You may select the horizontal mode by clicking the drop-down list
under Mode.
Measurement and Cursor Controls
1. The Measurements & Cursors button is located on the toolbar of the soft front panel.
2. Click to activate the automated measurement and cursor system.
This will display the window as shown below:
Figure B-11 – Soft Front Panel of the Measurement and Cursor Controls
3. The oscilloscope provides three types of settings for marker property, which are Auto,
Manual, and Off.
4. Auto marker automatically places the cursors on the graph based on the selected
measurements.
5. Manual marker allows the cursors to be placed manually on the graph for customized
measurements. This will enable the Cursors panel.
6. Off will disable the graph markers from the graph display.
7. If the Manual marker is selected, the Cursors control will be enabled. This is shown in Figure
.

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ME3000 Analog Electronics Lab 6 - 19/19
Figure B-12 – Cursor Controls
8. X Cursors places two cursors on the X-Axis of the waveforms to measure the time
difference between the two cursors (X2 minus X1). Delta X denotes the time difference.
9. Y Cursors places two cursors on the Y-Axis of the waveforms to measure the voltage
difference between the two cursors (Y2 minus Y1). Delta Y denotes the voltage difference.
AutoScale and Run/Stop
1. AutoScale automatically configures the oscilloscope to best display the input signal by
analyzing any waveforms connected to the channel and external trigger inputs. If AutoScale
fails, your current setup will remain unchanged.
2. Click on the oscilloscope toolbar or via the Tools menu once you have obtained
a running signal.
3. The auto scaling may take awhile for the application to analyze and adjust the waveform.
4. Once the auto scaling has completed, you will see a best fit waveform displayed on your
graph.
5. Use the Run/Stop button to manually start or stop the oscilloscope acquisition system for
acquiring waveform data.
6. You may click or to start or stop acquiring the waveform.