1. Engineering Portfolio
of
Isaac T. Bettendorf
Degree: BS in Electrical Engineering, concentration in
Computer Engineering
School: George Mason University Volgenau School of
Engineering
Graduated: Summa Cum Laude in December 2016
GPA: 3.98/4.0
Relevant Engineering and Technical Classes Taken:
1. CS222: Computer Program for Engineers
2. ECE220/320: Signals and Systems
3. ECE285/286: Electrical Circuit Analysis
4. ECE331: Digital Systems Design
5. STAT346: Probability for Engineers
6. ECE333/433: Linear Electronics (Microelectronics)
7. ECE431: Digital Circuit Design (Digital Microelectronic
Design)
8. ECE445: Computer Organization
9. ECE421: Classical System and Control Theory
10. ECE447: Single Chip Microcomputers
11. ECE460: Communication and Information Theory
12. ECE448: FPGA/ASIC Design with VHDL
13. ECE305: Electromagnetic Theory

2. ASLIM: Automated Slotted-Line Impedance Measurement Device
Team Members: Isaac Bettendorf, Valentina Morrison, Andrew Huttner, Charles Pritchard, Peter
Handjinicolaou, Ian Kanyamanza
Advisor: Dr. Peter Pachowicz
Figure 1: General system architecture and system signal flow of ASLIM Figure 2: Design Award

3. ASLIM: Automated Slotted-Line Impedance Measurement Device
Project Description:
• The purpose of the ASLIM Device is
to be an inexpensive alternative to a
digital network analyzer. This device
was designed to be capable of
performing all of the core
functionalities of a digital network
analyzer.
• The system automates the Slotted-
Line Impedance Measurement
method
Device Process Description (look at
Figure 1 for visualization):
1. The device generates a frequency
sweep with the signal generator.
2. Signals from signal generator travels
through the filter banks to eliminate
noise.
3. Signal travels through Slotted-Line
(copper coaxial transmission line
with thin vertical opening) and
power standing wave (PSW) is
formed within.
6. Power detector and position data go to
microcontroller (PIC24).
7. PIC24 controlled the runtime operation of
device including the control of the direction and
speed of power detector (using PWM) and the
control of signal generator and filter banks.
8. PIC24 then sends (via SPI) all data to
BeagleBone Black to be processed.
Figure 3: Front EagleCAD of 2 Ground Plane PIC24FJ
and motor driver PCB
4. Power detector moves vertically along Slotted-Line
sampling envelope of PSW.
5. Encoder keeps track of power detector’s position
Figure 4: Conceptual
Schematic of PIC24FJ
and motor driver PCB

4. ASLIM: Automated Slotted-Line Impedance Measurement Device
Personal Responsibilities on Project Team:
1) Project Manager:
• Administrative Duties: scheduling, record keeping, and
technical writing
• System Manager: directing flow of ideas, dividing
responsibilities among team mates, communication,
orchestrated top-down design approach and directed
integration/debugging at every stage of the design
process.
2) Microcontroller and Embedded System’s Engineer:
• Duties Performed: integration of hardware (PIC24 and
others) and software into a larger system; working with
tradeoff between power consumption, speed of
operation, cost, and size/area of device.
Further Specifications/Details of Project:
• Signal generator can perform sweep up to a range of
500MHz to 3 GHz
• User operates device through custom GUI
• Device displays antenna impedance at different
frequencies (Smith chart).
• Import and export data using file management
system
Figure 5: Showing how data travels from Slotted-Line, to PIC24,
and then to BeagleBone Black

5. Microcontroller Projects (ECE447)
Basic Material Used:
1) Resistors (100, 500, 1K, 10k, 30k Ohm)
2) Capacitors (1, 10 uF)
3) External Push Buttons
4) 4x4 Matrix Keypad
5) E336755 Color TFT LCD Display (1.8”)
6) MMA8451 Accelerometer
7) HC-SR04 Ultrasonic Sensor
8) MSP430FR6989 LanchPad
9) External LEDs (Red, Green, Yellow,
Blue)
10) Piezoelectric Buzzer
11) MCP4725 12-Bit DAC
General Description: There are nine different projects in all. These projects were part of
laboratory design experiments for the undergraduate class titled ECE447: Single-Chip
Microcomputer at George Mason University. This utilized the C language and some
assembly to program the MSP430FR6989 microcontroller (MCU).
Figure 6: MMA8451
Accelerometer
Figure 7: MSP430FR6989 LanchPad (center), E336755 TFT LCD (upper right), HC-SR04 (lower
right), External Buttons (lower left), 4x4 Matrix Keypad (upper left)

6. Microcontroller Projects (ECE447)
Project Descriptions and Concepts Learned:
1. Controlling LED by Polling Push Button: This project reviewed the
concept of polling and how to assemble a pull-up networks both
internal and externally to the MCU. (Resistor pull-up network for
external).
2. Extended Segmented Display: create basic “Snakes Game” that moves
around onboard LCD.
3. Continued Extended Segmented Display: Add functionality onto
previous assignments with ball that moves around onboard display
and adding external LEDs. Also utilized interrupt based inputs rather
than polling based inputs.
4. PWM and Matrix Keypad Decoding: Scan a 4x4 matrix keypad to
determine what button has been pressed.
Basic Concepts Utilized in Projects:
1) Polling Inputs
2) External Interrupts
3) Pulse Width Modulation (PWM)
4) Matrix Keypad Decoding

7. Microcontroller Projects (ECE447)
Project Descriptions and Concepts Learned Continued:
5. Timer Interrupts and Piezoelectric Buzzer: Using matrix keypad,
external LEDs, and Piezoelectric Buzzer, change pitch of piezoelectric
buzzer and ON state of external LEDs.
6. Ultrasonic Measuring Tap: Use the HC-SR04, timer capture mode,
and onboard LCD to create an ultrasonic distance measuring device.
7. Basic Logic Analyzer: Use the E336755 Color TFT LCD Display (1.8”)
which communicates via SPI to create a 4-channel digital logic
analyzer.
8. Move Ball on Graphical LCD with Accelerometer: Use the MMA8451
Accelerometer (which communicates via I2C) to move a ball around
on the E336755 Color TFT LCD Display (1.8”).
9. ADC and DAC Conversion: Use the internal 12-bit ADC and the
external MCP4725 DAC to first convert a sinusoidal signal from analog
to digital and then back from digital to analog.
Basic Concepts Utilized in Projects
Continued:
5) Basic Internal Timers and ISRs
6) Debouncing External Button Inputs
7) Timer Capture
8) Serial Peripheral Interface (SPI)
9) Inter-Integrated Circuit (I2C)
10) Analog-to-Digital Conversion (ADC)
11) Digital-to-Analog Conversion (DAC)

8. FPGA and ASIC Design with VHDL Projects (ECE445/ECE448)
General Description: There are seven projects in all but two of the projects were review exercises so they will
not be presented here. The first project was part of the George Mason University class titled ECE445: Computer
Organization. In this class, a MIPS processor was designed and created in VHDL with Xilinx ISE Design Suite 14.6
and then implemented on the Basys 2 Spartan-3E Trainer Board. The next four projects were part of the
George Mason University class titled ECE448: FPGA and ASIC Design with VHDL and were designed and created
in VHDL with Xilinx ISE Design Suite 14.7 and then implemented on the Nexys 3 Spartan-6 FPGA Trainer Board.
“Nexys 3 Spartan-6 FPGA Trainer Board (LIMITED TIME) >> see Nexys4 DDR,” Digilent. [Online].
Available: http://store.digilentinc.com/nexys-3-spartan-6-fpga-trainer-board-limited-time-see-
nexys4-ddr/. [Accessed: 24-Dec-2016].
“Basys 2 Spartan-3E FPGA Trainer Board (LIMITED TIME) >>see Basys 3,” Digilent.
[Online]. Available: http://store.digilentinc.com/basys-2-spartan-3e-fpga-trainer-board-
limited-time-see-basys-3/. [Accessed: 24-Dec-2016].
<< Figure 8: Basys 2 Spartan-3E FPGA
Trainer Board
Figure 9: Nexys 3 Spartan-6 FPGA Trainer Board >>

9. FPGA and ASIC Design with VHDL Projects (ECE445/ECE448)
Project Description and Concepts Learned:
1. Fully Functioning MIPS Processor in VHDL (ECE445):
Basics of computer architecture design and assembly
language.
2. Finite State Machine – Automated Teller Machine: Given
set of requirements, designed and implemented finite
state machines to carryout the required tasks.
(Automated movie ticket teller)
3. VGA Display – Snake Game: Designed a version of
Snakes (Snakes Game) and related digital circuits which
allowed the game to be displayed on a VGA monitor.
4. Mandelbrot Fractal Viewer: Design digital circuit to plot
a Mandelbrot fractal sets on VGA monitors.
5. Fast Sorting using PicoBlaze: Given a general datapath
in the requirements that utilizes PicoBlaze, I designed a
system that organized pseudo-random numbers and
there corresponding memory addresses from least to
greatest value.
Figure 10: Screenshot from Snake Game

10. Figure 11: four stage MOSFET amplifier with differential input
Microelectronics Circuit Design (ECE 333/433/431)
General Description: During the courses of ECE333/433/431, multiple OrCAD PSPICE projects were assigned
where both OrCAD Capture (circuit schematic construction of simulated circuit) or simple SPICE code was
utilized and simulation results were calculated and displayed in PSPICE A/D. There were multiple simple
assignments, but in ECE433 it was assigned to design a four stage differential amplifier which passed
requirements in areas such as gain, phase margin, unit-gain bandwidth, slew rate, etc.
Four Stage Amplifier Description:
Stage 01: Begins with a basic differential
amplifier. (M1, M2, M3, M4)
Stage 02: Common source amplifier
with C4 as a negative feedback route.
(M7, M6)
Stage 03: Common drain amplifier. (M8,
M9)
Stage 04: Common source amplifier.
(M11, M10)
M12 and M5 are part of a current
mirror used for biasing