FM Transmitter and Receiver - Ja

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					           EE3333ss

            Project 2

  FM Transmitter and Receiver

          Jason Durbin

        IEEE #90259979

            08/08/08




Instructor Name: Dr. Mark Storrs

       Advisor: Dr. Brian Nutter

Team Members: Osman Syed, Travis Horn
                                           Abstract


       The system discussed in this paper is an FSK transmitter and receiver. The system is

designed to operate in the 75 MHz frequency band following FCC regulations. The transmitter

VCO center frequency is at 75.7 MHz and is modulated using a digital signal to control a switch

that turns on and off a capacitor. The receiver is a superheterdyne receiver. This paper places

much detail on the design of the oscillators. All estimations and predictions are verified using an

oscilloscope or spectrum analyzer.




                                                ii
                                           Table of Contents


1  Introduction .................................................................................................................. 1
2  Transmitter.................................................................................................................... 2
  2.1 VCO ...................................................................................................................... 3
     2.1.1 Theoretical Analysis and Estimation............................................................... 5
     2.1.2 Testing and Physical Analysis......................................................................... 7
     2.1.3 Frequency Shifting ........................................................................................ 10
  2.2 Power Amplifier .................................................................................................. 11
3 Receiver ...................................................................................................................... 13
  3.1 Stage One ............................................................................................................ 14
  3.2 Stage Two ............................................................................................................ 15
     3.2.1 Mixers............................................................................................................ 15
     3.2.2 65 MHz Local Oscillator ............................................................................... 18
     3.2.3 10.7 MHz Local Oscillator ............................................................................ 22
     3.2.4 Voltage Comparator ...................................................................................... 26
  3.3 Stage Three .......................................................................................................... 27
4 Conclusions ................................................................................................................ 29
5 References .................................................................................................................. 30
Appendix A: Discussion of Crystal Implemented in VCO Transmitter ........................ 31
Appendix B: Budget ....................................................................................................... 32
Appendix C: Gantt Chart................................................................................................ 34
Appendix D: Safety Evaluation...................................................................................... 36
Appendix E: Evaluation Form........................................................................................ 37




                                                           iii
                                             List of Figures


Figure 1: Transmitter Block Diagram ................................................................................. 2
Figure 2: Receiver Block Diagram ..................................................................................... 2
Figure 3: Transmitter VCO Schematic Diagram ................................................................ 3
Figure 4: Transmitter VCO Board Layout .......................................................................... 4
Figure 5: Transmitter VCO top and bottom ........................................................................ 5
Figure 6: Output of Transmitter VCO on Oscilloscope ...................................................... 8
Figure 7: Output of Transmitter VCO on Spectrum Analyzer ........................................... 8
Figure 8: Spectrum Analyzer Output of Transmitter VCO Showing Harmonics ............... 9
Figure 9: Spectrum Analyzer Output of Frequency Shift Keying of the Transmitter ...... 11
Figure 10: Power Amplifier Schematic Diagram ............................................................. 12
Figure 11: Power Amplifier Board Layout ....................................................................... 12
Figure 12: Milled Power Amplifier .................................................................................. 13
Figure 13: Receiver Block Diagram ................................................................................. 13
Figure 14: Low Noise Amplifier Schematic Diagram ...................................................... 14
Figure 15: Low Noise Amplifier Board Layout ............................................................... 15
Figure 16: Milled Low Noise Amplifier ........................................................................... 15
Figure 17: Mixer Schematic Diagram............................................................................... 16
Figure 18: Built Mixers..................................................................................................... 17
Figure 19: Mixer Output on Spectrum Analyzer .............................................................. 18
Figure 20: 65 MHz Local Oscillator Schematic Diagram ................................................ 19
Figure 21: 65 MHz Local Oscillator Board Layout .......................................................... 20
Figure 22: Milled 65 MHz Local Oscillator ..................................................................... 20
Figure 23: 65 MHz Output on Oscilloscope ..................................................................... 21
Figure 24: Output of 65 MHz Local Oscillator on Spectrum Analyzer ........................... 22
Figure 25: 10.7 MHz Local Oscillator Schematic Diagram ............................................. 23
Figure 26: 10.7 MHz Local Oscillator Board Layout ....................................................... 24
Figure 27: Output of 10.7 MHz Local Oscillator on Oscilloscope ................................... 25
Figure 28: Spectrum Analyzer Output of 10.7 MHz Local Oscillator ............................. 25
Figure 29: Schmitt Trigger................................................................................................ 26
Figure 30: Phase Lock Loop Diagram .............................................................................. 28
Figure 31: Example Output of the Phase Lock Loop ....................................................... 29
Figure 32: Gantt Chart ...................................................................................................... 34
Figure 33: Gantt Chart Continued..................................................................................... 35




                                                         iv
                                             List of Tables


Table I: FCC regulated RC Car/Boat Frequencies ............................................................. 1
Table II: Proposed Budget ................................................................................................ 32
Table III: Final Budget...................................................................................................... 33




                                                         v
                                    1      Introduction

       Frequency shift keying (FSK) is a method of controlling remote controlled vehicles. The

system discussed in this paper is an FSK system. The system consists of a transmitter and

receiver. The transmitter and receiver must operate in the 75 MHz frequency band (specifically

allocated by the FCC for RC boats and cars). Table I shows the channels for RC boats and cars.


                     Table I: FCC regulated RC Car/Boat Frequencies [1]
                        Frequency Channel Frequency Channel
                            75.41     61      75.71     76
                            75.43     62      75.73     77
                            75.45     63      75.75     78
                            75.47     64      75.77     79
                            75.49     65      75.79     80
                            75.51     66      75.81     81
                            75.53     67      75.83     82
                            75.55     68      75.85     83
                            75.57     69      75.87     84
                            75.59     70      75.89     85
                            75.61     71      75.91     86
                            75.63     72      75.93     87
                            75.65     73      75.95     88
                            75.67     74      75.97     89
                            75.69     75      75.99     90


       The FCC states that “your RC station may not transmit simultaneously on more than one

channel;” implying that the maximum bandwidth of each channel is 20 kHz [1]. The FCC also

states the maximum output power for a 72-76 MHz signal is 750 mW [1].

       The transmitter consists of one VCO operating at the carrier frequency, 75.79 MHz. The

carrier signal is modulated by a digital signal using the VCO. The signal is then amplified,




                                               1
filtered, and transmitted. Figure 1 shows the block diagram for the transmitter. The receiver is a

superheterodyne receiver. Figure 2 shows the block diagram for the receiver.




                               Figure 1: Transmitter Block Diagram




                               Figure 2: Receiver Block Diagram [2]



                                       2       Transmitter

       Figure 1 shows the block diagram for the transmitter. The only fully functional stage of

the transmitter is the VCO. The power amplifier is realized, but not functional. The bandpass

filter is not realized; however the need for the bandpass filter will discussed in further detail.



                                                   2
2.1 VCO

       The VCO of the transmitter is Colpitts design oscillator with a switching capacitor to

shift the frequency. The VCO is only able to shift between two frequencies (as needed for FSK).

Figure 3 shows the schematic diagram for the VCO.




                        Figure 3: Transmitter VCO Schematic Diagram


       The left section is the Colpitts oscillator design. The decoupling capacitors C1 and C2

and RFC1 are added to prevent oscillations on Vcc. C4 and L2 are tunable to adjust the carrier

frequency. C10 is tunable to adjust the frequency difference between a mark and a space. RFC2


                                              3
is added to allow greater transfer of power to the load. Both RFCs are designed to be about 15

kΩ are resonant frequency. P1 and P2 are test points. R8 is a pull-down resistor.

       Figure 4 shows the board layout of the oscillator. The top layer of the board (not shown)

is a ground plane. All the traces are on the bottom layer. All traces are at least 80 mils wide; with

the exception of the trace for the digital signal controlling the switch. Large traces reduce

inductance. All dead copper is removed, leaving just traces. Figure 5 shows the final milled

board of the transmitter VCO.




                            Figure 4: Transmitter VCO Board Layout




                                                 4
                           Figure 5: Transmitter VCO top and bottom


2.1.1 Theoretical Analysis and Estimation

       Equation 1 shows the Colpitts estimation for frequency of oscillation. Equation 2 shows

the effective capacitance as seen by the inductor. Parasitic capacitances of the BJT and the

capacitance of the crystal are neglected in this approximation. Using the two equations, it can be

shown that the frequency is estimated to range between 67.2996 MHz and 100.7327 MHz.




                         1
         f0 
                 2 LCeff                                                           (1)
                                               1
                 1    1   1 
        Ceff               C4                                                 (2)
                 C 5 C8 C8 
                                                5
       Similarly, the frequency shift provided by C10 can be approximated. Equation 2 is

modified to include C10 (equation 3). First L2 and C4 are set to their maximum, .2 µH and 5 pF,

respectively, to find the shifting range provided by C10 at the lower extreme of the carrier

frequency (67.2996 MHz). When C10 is 5 pF and the switch is on (C10 is grounded) the

resonant frequency shifts to 67.1646 MHz. When C10 is 2 pF the resonant frequency shifts to

67.2446 MHz. At 67.2996 MHz (lower extreme carrier frequency) the shift provided by C10 can

vary between 55 kHz to 135 kHz.



                                                  1
                    1      1   1 
       Ceff                     C4                                          (3)
                C 5  C10 C8 C8 

       Next, L2 and C4 set to their minimums to determine the shifting range at the upper

extreme of the carrier frequency (100.7327 MHz). When C10 is 5 pF, the frequency shifts to

100.5066; C10 at 2 pF shifts the frequency to 100.6406 MHz. At 100.7327 (upper extreme

frequency) the shift provided by C10 can range between 92.1 kHz to 226.1 kHz. Concluding

from both extremes, C10 can provide a shift of frequency from between 55 kHz to 226.1 kHz,

depending on the values of L2 and C4.

       At 75.7179 MHz (L2 = .158 µH, C4 = 5 pF), C10 may vary the frequency by between

73.4 kHz and 163.5 kHz. Again, these approximations are neglecting the parasitic capacitances

of the BJT and the capacitance of the crystal. Testing and physical analysis for these

approximations follows.




                                              6
2.1.2 Testing and Physical Analysis

       Vcc is 10 V. Output is taken at the BNC connector and the load is always 50 Ω unless

noted otherwise. The output series resistor, Ro, must be added to boost the impedance of the

load; otherwise the oscillator cannot oscillate. The 220 Ω at the collector of Q2, R2, is shown in

the schematic diagram to change the bias point of the transistor in the case it is not biased

correctly. For all testing purposes, R2 is shorted.

       Figure 6 shows the output of the oscillator on the oscilloscope. The peak-to-peak voltage

of the waveform at 75.79 MHz is 492 mV. Figure 7 shows the output of the oscillator on a

spectrum analyzer zoomed in to the carrier. The output power of the oscillator at 75.79 MHz is

-2.81 dBm or .724 mW. As the frequency is varied using the tuning capacitor, C4, or the tuning

inductor, L2, the peak-to-peak voltage and output power changes. However, the primary focus of

the VCO is to produce a 75 MHz sinusoidal signal. Output power is the primary focus of the

power amplifier.




                                                  7
  Figure 6: Output of Transmitter VCO on Oscilloscope




Figure 7: Output of Transmitter VCO on Spectrum Analyzer

                           8
       As can be seen from the oscilloscope trace, the waveform is distorted from an ideal

sinusoidal wave. Figure 8 shows the output of the VCO on the spectrum analyzer with a widened

span. The waveform from the VCO contains many harmonics. Although the fundamental

frequency is 25 dB larger than the nearest harmonic, the output must still be filtered. No

frequencies outside the allocated bandwidth may be transmitted.




         Figure 8: Spectrum Analyzer Output of Transmitter VCO Showing Harmonics


       The carrier frequency is intended to be locked to the frequency of the crystal; however

measurements prove otherwise. As the oscillator warms, the carrier frequency will drift. No

datasheet for the crystal was located; however it is assumed that crystal is being operated in the

wrong mode. Appendix A goes into further detail about the possible problem. Because the


                                                9
crystal does not lock the frequency, the VCO carrier frequency is variable. Using the tunable

inductor and capacitor the carrier frequency can be tuned to between 66.052 MHz to 82.772

MHz. The Colpitt‟s estimation (above) yielded between 67.3 MHz and 100.73 MHz; however

the estimation excluded parasitic capacitance of the BJT and the capacitance of the crystal.


2.1.3 Frequency Shifting

       A function generator with a 50 Ω source resistor is connected to „Dig‟ input. The function

generator is set to output a square wave (50% duty cycle signal) between 0 V (logic low) and 5 V

(logic low). A digital low turns the switch off, disconnecting C10 from ground; conversely for a

digital high. Figure 9 shows the output of the oscillator while frequency shift keying. The

frequency of the square wave is turned up high enough to allow both frequencies to appear

simultaneously on the screen of the spectrum analyzer (aliasing).

       The lower bump on Figure 9 is known as the “space” and the upper hump is the “mark.”

The carrier frequency lies in the middle of the two bumps (not transmitted). The difference

between the mark and the space (or “shift”) depicted in Figure 9 is approximately 10 kHz. Upon

analysis, by varying C10, the difference can range between 4 kHz to 20 kHz (at 75.79 MHz).

This outcome is much different than estimated in previously; however, this outcome is more

favorable because the difference must be less than 20 kHz (FCC regulation on bandwidth).




                                                10
       Figure 9: Spectrum Analyzer Output of Frequency Shift Keying of the Transmitter


2.2 Power Amplifier

       A power amplifier must be used to transmit the FSK signal over the air. A class C

amplifier is used. The maximum output power must be less than 750 mW (FCC regulations).

       Figure 10 shows the schematic diagram of the power amplifier. The preamplifier (ERA-

8SM) will increase the voltage of the oscillator to be large enough to turn on the following

amplifier. Figure 11 shows the board layout of the power amplifier. Figure 12 shows the milled

power amplifier. Upon testing the power amplifier, neither stage work. The pre-amplifier clips

the incoming signal and the power amplifier never turns on [3].




                                               11
Figure 10: Power Amplifier Schematic Diagram [3]




  Figure 11: Power Amplifier Board Layout [3]




                      12
                               Figure 12: Milled Power Amplifier [3]



                                         3       Receiver

       The receiver is a superheterdyne receiver. Figure 13 shows the block diagram for the

receiver. For the purpose of this paper, the receiver is split into three stages. Stage one consists of

the first bandpass filter and low-noise amplifier. Stage two consists of the mixers, local

oscillators, the remaining bandpass filters, and the first voltage comparator. Stage three is the

phase comparator, low pass filter, VCO, and remaining voltage comparator.




                              Figure 13: Receiver Block Diagram [2]




                                                  13
3.1 Stage One

        Stage one consists of the first bandpass filter and the low noise amplifier. The bandpass

filter is tuned at the carrier frequency (75.79 MHz for this system) with a small bandwidth

(around 20 kHz). The bandpass filter is needed to filter out all signals except the desired signal to

be received. The bandpass filter is not built.

        The LNA amplifies the signal after the bandpass filter. It must add very little noise to the

signal, because the signal from the bandpass filter will be small. Figure 14 shows the schematic

diagram of the low noise amplifier. Figure 15 shows the board layout of the low noise amplifier.

Figure 16 shows the milled board of the LNA. The LNA does not work; the output voltage of the

signal is less than the input signal [3].




                      Figure 14: Low Noise Amplifier Schematic Diagram [3]




                                                 14
                        Figure 15: Low Noise Amplifier Board Layout [3]




                           Figure 16: Milled Low Noise Amplifier [3]


3.2 Stage Two

       Stage two of the receiver consists of the two local oscillators, the two remaining bandpass

filters, the mixers, and a voltage comparator.


3.2.1 Mixers

       The mixers of the receiver are used to decrease the frequency of the signal. The incoming

75.7 MHz (±5 kHz) sinusoidal signal is mixed with a 10.7 MHz LO, producing frequency


                                                 15
components of 65 MHz and 86.4 MHz. The 86.4 MHz is filtered by the bandpass filter, leaving

the 65 MHz signal. The signal is mixed again with 65 MHz and filtered again. The remaining

frequency is the ± 5kHz signal from the “mark” or “space” sent from the transmitter.

       The mixers for the receiver are simple diode ring mixers. Figure 17 shows the schematic

diagram of the mixers used in the receiver. Figure 18 shows the mixers as they are built.




                            Figure 17: Mixer Schematic Diagram [2]




                                               16
                                  Figure 18: Built Mixers [2]


       To test the mixers, a high frequency function generator is used to provide a LO of 60

MHz [2]. The LO is mixed with a signal with a frequency of 2 MHz. Figure 19 shows the output

of a mixer on the spectrum analyzer. Both mixers performed similarly [2]. The large spike in the

middle is the LO of 60 MHz. The two smaller spikes are 58 MHz and 62 MHz; proving the

mixer works correctly [2].




                                              17
                       Figure 19: Mixer Output on Spectrum Analyzer [2]


3.2.2 65 MHz Local Oscillator

       The 65 MHz LO is similar to the VCO for the receiver; except no switch exists on the

LO. Figure 20 shows the schematic diagram of the 65 MHz LO. The oscillator employs crystal

matched to the crystal of the transmitter. The crystal does not lock the frequency as it should; so

the resonant frequency varies (discussion in Appendix A). The resonant frequency will vary

between 62.53 MHz and 74.08 MHz.




                                                18
                    Figure 20: 65 MHz Local Oscillator Schematic Diagram


       C1, C2, and RFC1 are to prevent oscillations on Vcc. Figure 21 shows the board layout

for the 65 MHz local oscillator. The top layer is a ground plane and the bottom layer is the

traces. The traces are no less than 80 mils wide to reduce inductance. All dead copper is removed

from the bottom layer. Figure 22 shows the milled board of the 65 MHz LO.




                                               19
Figure 21: 65 MHz Local Oscillator Board Layout




   Figure 22: Milled 65 MHz Local Oscillator




                      20
       Vcc is supplied with 10 V from a power supply. The 220 Ω resistor added in case of

biasing issues, R2, is shorted. The 1kΩ source resistor is added, as in the transmitter VCO, to

allow a large enough impedance to not affect the oscillator. Output is connected at the BNC

connector. All output loads are 50 Ω unless otherwise noted. Figure 23 shows the output of the

oscillator on an oscilloscope. The peak-to-peak voltage of the signal is 408 mV; however, this is

not large enough to turn the diodes in the mixers. A peak voltage of 1.4 V (peak-to-peak of 2.8

V) is needed to turn on both diodes in the mixers [2].




                            Figure 23: 65 MHz Output on Oscilloscope


       Figure 24 shows the output of the 65 MHz LO on the spectrum analyzer. The spectrum

analyzer shows many harmonics which need to be filtered before the mixers. A low pass filter

can be placed after the oscillator to rid the output of harmonics.



                                                 21
              Figure 24: Output of 65 MHz Local Oscillator on Spectrum Analyzer


3.2.3 10.7 MHz Local Oscillator

       The 10.7 MHz LO is nearly identical to the 65 MHz LO. Capacitor and inductor values

are changed and the crystal is removed. The 10.7 MHz LO is intended to be variable for

selecting channels; however, the crystal of the 65 MHz LO should ideally lock to the channel of

the carrier. Figure 25 shows the schematic diagram for the 10.7 LO. Figure 26 shows the board

layout for the oscillator. All traces are at least 80 mils wide. Top layer is a ground plane and all

dead copper is removed from the bottom layer.




                                                22
Figure 25: 10.7 MHz Local Oscillator Schematic Diagram




                         23
                      Figure 26: 10.7 MHz Local Oscillator Board Layout


       The setup for testing the 10.7 LO is identical to the 65 MHz LO. However, the source

resistor for this LO is smaller. The 220 Ω resistor is shorted. Vcc is 10 V as supplied by a power

supply. Output is taken at the BNC connector. All loads are 50 Ω unless otherwise noted. Figure

27 shows the output of the oscillator on the oscilloscope. The peak-to-peak voltage is 236 mV;

and as mentioned, will not turn on the diodes in the mixer. Figure 28 shows harmonics of the

10.7 MHz oscillator. As in the 65 MHz LO, a low pass filter will need to be added to filter off

the harmonics.




                                               24
 Figure 27: Output of 10.7 MHz Local Oscillator on Oscilloscope




Figure 28: Spectrum Analyzer Output of 10.7 MHz Local Oscillator

                              25
3.2.4 Voltage Comparator

       The voltage comparator employed in the receiver is a Schmitt trigger. The voltage

comparator is needed to convert the sinusoidal waveform of the mixers into a square wave. A

square wave with a low of 0 V and a high of 5 V is needed at the input of the PLL because the

PLL uses a XOR gate for phase comparing.

       A Schmitt trigger is employed because of the hysteresis provided. A Schmitt trigger is

achieved by adding positive feedback to a voltage comparator. Figure 29 shows the schematic

diagram for the Schmitt trigger. Equation 4 is the approximation to find the voltage thresholds to

allow Vout to switch between a low and high voltage. Estimation in finding the thresholds

follows.




                                   Figure 29: Schmitt Trigger




                                               26
                    Rin                 Rin 
       Vin              Vout  Voff 1 
                                             
                    Rf                   Rf                                        (4)

       The op-amp is assumed to be rail-to-rail and Vcc is 5 V. Voff is 2.5 V. The ratio of

Rin/Rf is set to be 1/70 [2]. To find the threshold voltage of Vin for Vout to go from low to high,

Vout is first set to 0 V. By substitution, equation 4 yields 2.54 V. Conversely, to find the

threshold of Vin for Vout to go from high to low, Vout is set to 5 V. Equation 4 yields 2.46 V.

Concluding that the output voltage will switch from low to high at 2.54 V and from high to low

at 2.46 V. Upon testing the Schmitt trigger, the actual thresholds are approximately 2.77 V and

2.71 V, respectively [2].


3.3 Stage Three

       Stage three is the phase lock loop (PLL). The PLL consists of a phase comparator (a

XOR gate), a low pass filter, a VCO, and a voltage comparator. Figure 30 shows the diagram of

the PLL employed in the receiver.

       The frequency of the incoming digital signal from the Schmitt trigger is compared to the

frequency of the VCO using the phase comparator. The duty cycle of the output signal of the

phase comparator varies as the phase differences vary. Large phase differences produce large

duty cycles on the signal. If the signals are 180 degrees out of phase, the duty cycle of the signal

is 100% or a constant high voltage. Conversely, if the signals are completely in phase, the output

voltage of the phase comparator is constantly low.




                                                27
                             Figure 30: Phase Lock Loop Diagram [2]


       The signal from the phase comparator is filter by a low pass filter. The voltage output

from the filter is close to a DC voltage. Another Schmitt trigger is employed following the low-

pass filter to convert the DC voltage to either a logically low or high. For example, if a „space‟ is

transmitted, the recovered signal after the Schmitt trigger would be low; conversely if a mark is

transmitted, the recovered signal is high. Figure 31 shows an example output of the PLL. Each

graph shows the input signal of the PLL on the top and the output voltage of the PLL on the

bottom. The left graph shows a space, producing a low, and the right shows a space, producing a

high [2].




                                                 28
                     Figure 31: Example Output of the Phase Lock Loop [2]


                                      4       Conclusions

       Frequency shift keying is commonly used in remote controlled vehicles. The system

discussed consists of a transmitter and receiver. The transmitter and receiver must follow the

guidelines of the FCC. The transmitter consists of a VCO, power amplifier, and filter. The

receiver is a superheterodyne receiver.

       The VCO for the transmitter works correctly. The carrier frequency of the VCO is

modulated by a digital signal by switching a variable capacitor on and off. The carrier frequency

is intended to be locked with a crystal; however it is not locked and is variable. The power

amplifier is built, but does not work. The filter was never built.

       Each important component of the receiver works independently. The diode ring mixers

work correctly. The local oscillators work correctly and at the correct frequency. The phase lock

loop is capable of outputting digital signals in correlation to a mark or space. However, when the

components are placed together, the system will not work.

                                                 29
                                  5       References

      1. Vantec. FCC Regulations and Radio Control. Vantec. [Online] 2007. [Cited: August 6,

2008.] http://www.vantec.com/FCCregs1.htm.

      2. Horn, Travis. Final Presentation. August 2008.

      3. Syed, Osman. Final Presentation. August 2008.




                                             30
   Appendix A: Discussion of Crystal Implemented in VCO Transmitter


       The crystal employed in the transmitter VCO and the 65 MHz LO was acquired from a

hobby store. No datasheet for the crystal could be located. The transmitter crystal operates at

75.79 MHz. However, a crystal has two frequencies of operation frequently used, a series

resonant frequency and a parallel resonant frequency.

       The implementation of the crystal for the VCO and the LO is intended to be in the series

resonance mode (a short at the frequency of interest). If the crystal is working properly, it will

“pull” the resonant frequency of the oscillator to that of the crystal by adding capacitance or

inductance. However, from testing the VCO and LO, the crystal does not lock the frequency as

intended. The conclusion from testing is that the 75.79 MHz operation mode is the parallel

resonant mode. For the transmitter VCO and 65 MHz LO to be locked correctly, the oscillators

will need to be redesigned to implement the crystals into a parallel resonance mode.




                                               31
                                   Appendix B: Budget

       This appendix shows the proposed and final budget for the development of this system.

Due to overestimation of hours and parts cost, the development remained under budget.


                                  Table II: Proposed Budget
                                      Proposed Budget
                     Name           Hours      Weeks         Pay       Total
            Jason                         20         10          $15 $3,000.00
            Travis                        20         10          $15 $3,000.00
            Osman                         20         10          $15 $3,000.00
                                                    Total Labor Cost: $9,000.00
                                                      75% Overhead: $6,750.00
                                                Overhead Plus Labor: $15,750.00

                                           Parts Cost
                                   Price Per       Total
                    Part             Unit          Units                     Total Price
            Transmitter Parts          $50.00            10                    $500.00
            Receiver Parts             $50.00            10                    $500.00
            Bread Board                 $5.00             4                      $20.00
            Misc                      $100.00             1                    $100.00
            Misc Components             $5.00            50                    $250.00
                                                              Total Parts:    $1,370.00

                                       Equipment Rental
                                                Rental           Days
              Equipment Name         Price       Rate           Rented       Total Cost
            Oscilloscope            $3,920.00      $7.84              70       $548.80
            Spectrum Analyzer       $3,000.00      $6.00              70       $420.00
            Multimeter                $259.00      $0.52              70        $36.26
            Computer                $2,000.00      $4.00              70       $280.00
            Keys                       $14.00      $0.03              70          $1.96
            Function Generator        $349.00      $0.70              70        $48.86
            Function Generator        $349.00      $0.70              70        $48.86
            Soldering Iron             $49.99      $0.10              70          $7.00
            Power Supply              $689.00      $1.38              70        $96.46


                                              32
                      Miscellaneous Cables            $12.98        $0.03            70        $1.82
                                                                      Total Rental Cost:   $1,490.02
                                                                Total Proposed Budget:      $18,610

                                                  Table III: Final Budget
                        Actual Budget
 Name         Hours                      Pay      Total
Jason                 190                   $15     $2,850
Travis                180                   $15     $2,700
Osman                 180                   $15     $2,700
                               Total Labor Cost: $8,250.00
                                75% Overhead: $6,187.50
                                 Overhead Plus
                                         Labor: $14,437.50

                                     Parts Cost
                              Price
                               Per        Total                      Total
                Part          Unit        Units                      Price
         10 nH Inductor        $0.40              3                     $1.2
         22 uH Inductor        $1.04              4                   $4.16
         Variable Inductor     $0.51              5                   $2.55
                                                            Total
                                                           Parts:      $7.91

                                                          Equipment Rental
           Equipment         Total                      Rental    Checked          Date         Days
              Name           Units       Price           Rate       Out         Checked In     Rented     Total Cost
         Multimeter                  1  $259.00            $0.52    6/1/08     8/7/2008 Y           67           $34.71
         Power Supply                1  $389.00            $0.78    6/1/08     8/7/2008 Y           67           $52.13
         Computer                    1 $1,000.00           $2.00    6/1/08     8/7/2008 Y           67          $134.00
         Spectrum
         Analyzer                  1 $2,500.00             $5.00     6/1/08    8/7/2008    Y        67         $335.00
         Misc Cables              10     $4.00             $0.08     6/1/08    8/7/2008    Y        67           $5.36
                                   1     $4.00             $0.01    6/24/08    8/7/2008    Y        44           $0.35
         Keys                      1    $14.00             $0.03     6/1/08    8/7/2008    Y        67           $1.88
         Function
         Generator                   2   $349.00           $1.40     6/1/08    8/7/2008 Y           67          $93.53
         High Freq. Func.
         Gen                         1 $4,000.00           $8.00    6/24/08    8/7/2008 Y           44        $352.00
         Oscilloscope                1 $3,000.00           $6.00     6/1/08    8/7/2008 Y           67        $402.00
                                                                                     Total Rental Cost:      $1,410.95
                                                                                 Total Budget To Date:        $15,856

                                                               33
                         Appendix C: Gantt Chart

This appendix shows the Gantt chart for the development of the project.




                             Figure 32: Gantt Chart




                                       34
Figure 33: Gantt Chart Continued




              35
                               Appendix D: Safety Evaluation

          Two of the largest safety concerns in the development of this project are with the

soldering iron and milling machine. Burns can be prevented by taking care in using the soldering

iron. Placement of the soldering iron on a stand is the easiest way to prevent burns

          The milling machine is a very dangerous machine if not carefully operated. Safety

goggles must always be worn to prevent copper shards from entering the eyes. The operator must

stand back from the milling machine while it is operation to prevent clothing or hair from being

caught in the fast spinning spindle. The operators hands must not be placed anywhere near the

milling machine.

          The largest voltage used in the design of this system is no more than 10 V, as supplied by

the power supply. Large current may exist in components such as the power amplifier.

          Other tools used were a screw driver, Allen wrench, wire stripper, wire cutters, and

pliers.




                                                  36
                       Appendix E: Evaluation Form

WRITTEN LAB REPORT EVALUATION FORM

Student Name: Course Number:

Please score the student by circling one of the responses following each of the statements.

1) The student's writing style (clarity, directness, grammar, spelling, style, format, etc)

         A     B       C       D       F        Zero

2) The quality and level of technical content of the student's report

         A     B       C       D       F        Zero

3) The quality of results and conclusions

         A     B       C       D       F        Zero

4) Quality of measurements planned/ taken

         A     B       C       D       F        Zero

Grade:




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