• Finite antenna array modeling and mutual coupling effects on element by element active reflection coefficient

  • Electromagnetic interference/compatibility (EMI/EMC) modeling and analysis on various cable bundle designs between electronic systems within a helicopter

  • Detailed simulation model construction of a turnstile dual-polarized dipole array antenna

  • Element pattern characterization and extraction from a space-fed array: Simulated (solid) and measured (dotted) array pattern line cuts for various scan angles

  • Pattern reconfigurable antenna with endfire radiation characteristics: Active element pattern gain vs. scan and frequency antenna array modeling

  • Polar plot: optimized radiation characteristics of modeled reconfigurable antennas in an adaptive array environment

  • Adaptive array concept with integrated weight and antenna element level reconfigurability control in an RF beamforming adaptive array receiver architecture

Research Interests

  • Applied electromagnetics
  • Phased arrays – design, modeling, analysis, and characterization
  • Antenna array reconfigurability, arrays synthesis, beamforming
  • Multifunctional wireless communication and radar systems

Initiatives

  • Advancing functionality at the front-end of communication and radar systems that utilize multiple antennas
  • Platform and system level integration of phased array antenna systems with adaptive and multifunctional characteristics
  • Expanding small array functionality in wireless sensor networks and smart sensor technologies requiring interference mitigation through spatial means
  • Transforming and integrating array functionality into emerging and next-generation wireless communication technologies
  • Integrating multifunctional antenna/antenna array technologies with novel physical materials and manufacturing techniques

Funding Activities

  • Co-Principal Investigator; Title: “Electrically Small Antenna Research and Support: Literature Review of Circular, Linear, and Dual-Polarized Patch Antennas and Benefits Thereof”; Sponsor: U.S. Federal Government; Status: Funded; Award Period: 05/2016 – 08/2016
  • Principal Investigator – Non-lead organization; Title: ”EARS: Collaborative Research: Wireless Agility – A Key Component in Bridging Emerging Technologies, Autonomous Agents, and Spectrum Management”; Sponsor: NSF; Status: Not Funded ; Proposal Period: 09/2016 – 09/2019
  • Principal Investigator; Title: ”Modeling Pattern Reconfigurable Antennas for use in Adaptive Arrays”; Sponsor: Postdoctoral Research Associateship program (RAP), Air Force Research Lab –Sensors Directorate, Dayton OH, 06/2010; Status: Not Funded

Project Activities

  • Antenna lead: Preliminary design and development of a Geo-Fence radar for small unmanned aerial systems for weather observations
    • Preliminary investigation on the design and development of a Geo-Fence radar for small unmanned aerial systems (UAS) weather observations; Contributed to the antenna/front-end hardware aspects of the design;  National Severe Storms Lab (NSSL)/ARRC, OU, 01/2016 – 08/2016 
  • Task lead: Antenna array radiator development for a 2D space-fed phased-array radar antenna
    • Antenna array radiator development for an advanced anti-aircraft threat simulator requiring the production of a 2D space-fed phased-array radar antenna; Designed and characterized RF performance of the radiator in its array environment for several possible design variations; Collaborated with the mechanical team to predict effects from the mechanical design specifications on radiator performance; GTRI, 05/2014 – 05/2015
  • Task lead: Wideband antenna array for a passive multi-static radar system
    • Design and development of a wideband antenna array for a passive multi-static radar system that supports increasing future capabilities to detect targets in real time with advanced beamforming techniques; Utilized EM software to aid in meeting scan and bandwidth specifications; Worked with team members in design of array’s mechanical support structure; Internal R&D effort, GTRI, 01/2014 – 09/2014
  • Lead system engineer: Investigating the combined effects of cyber and electronic attack on a passive coherent radar
    • Supported efforts to assess, identify, and analyze cyber-EW vulnerabilities of a passive coherent radar (PCR) system with the end goal of then using the assessments to (1) rank and identify common vulnerabilities, and (2) develop test bed requirements and concepts for exploring, developing and testing cyber-EW techniques with a hardware prototype.  Tasks included intelligence search on the PCR, composing high level system/layered architecture block diagrams, and identifying system functions and their input/outputs; GTRI, 02/2014 – 08/2014
  • Technical Contributor: Array RF performance study for a long range discrimination radar
    • Supported the study on array RF performance for a Long Range Discrimination Radar (LRDR): Characterized polarization and gain loss versus scan angle to establish the achievable upper bounds on performance; Results then gives the customer limiting factors to consider in the array design process; GTRI, 02/2014 – 05/2014
  • Technical Contributor: EMC/EMI analysis on critical system components on military helicopter aircraft
    • Investigated methods using electromagnetic simulation software (FEKO) to model the direct lightning effects on critical system components on an OH-58 model helicopter aircraft; Tasks included constructing preliminary models for analysis as part of the Phase 1 feasibility study and performing a detailed analysis in understanding and validating the modeling tool’s capabilities and limitation; GTRI, 07/2013 – 02/2014
  • Technical Contributor: Development and validation of an electromagnetic scattering model of a radar antenna in the presence of an RF obstruction
    • Designed an electromagnetic scattering model representative of a phased array radar antenna in the presence of an electrically large RF obstruction utilizing simulation and computer software; Design and characterize the phased-array’s antenna element response and assisted the measurement team in an on-site measurement campaign to procure field data to validate the electromagnetic scattering model; GTRI, 04/2012 – 12/2013
  • Lead system analyst: Technical evaluation and analysis on an air surveillance radar system
    • Pre-Integrated Technical Evaluation and Analysis of Multiple Sources (ITEAMS) effort on a foreign threat air surveillance radar system: Conducted an all source intelligence analysis in order to provide a baseline threat assessment of the radar’s observable features and characteristics; Supervised and consulted with subject matter experts in assessing sub-system performance capabilities; GTRI, 10/2012 – 10/2013
  • Technical Contributor: Radar auxiliary antenna characterization in presence of its electrically large antenna structure
    • Characterized the performance of a radar’s auxiliary antenna in the presence of the full electrically large antenna structure by integrating measured data taken from the isolated auxiliary antenna into a FEKO simulation model in order to assess its operational survivability against electronic attack; GTRI, 12/2013 and 07/2011 – 08/2011
  • Technical Contributor: Phased-array element response characterization and electronic counter measure assessment
    • Utilized computer and EM software to design and analyze a foreign-based  phased-array’s antenna element response; Researched foreign electronic counter measure (ECM) techniques to assist in assessing system capabilities and limitations of the phased-array radar; Contributions part of an Integrated Technical Evaluation and Analysis of Multiple Sources (ITEAMS) effort; GTRI, 10/2010 – 10/2011 and 01/2014 – 09/2014
  • Technical Contributor: Simulation of a complex radar scenario using a radar modeling tool
    • Designed and simulated a complex radar scenario for multiple projects using an Adaptive Sensor Prototyping ENvironement (ASPENTM) modeling tool to determine effects on radar performance; Integrated specific antenna array and environment requirements within the tool; Tasks included modeling both an advanced ECM technique in multifaceted radar environment and a multipath radar-to-target engagement scenario which included that included various clutter configurations; GTRI, 02/2012 – 07/2012
  • Technical Contributor: Wideband phased-array modeling and analysis alternative solution study
    • Designed and evaluated an alternative antenna element solution for use in wideband, counter-advanced threat phased-array radar system; Work provided much insight into the array’s radiation characteristics for the given constraints and led to adjustments in the mainstream solution design which improved simulation performance; GTRI, 10/2011 – 01/2012

Capabilities

  • Familiarity with principles of EM and antenna theory, RF circuit principles, and system engineering aspects of radar systems
  • Proficient in electromagnetic modeling and simulation of complex structures
  • Expertise in antenna and phased-array design, modeling, and analysis of applied systems
  • Knowledge in utilizing computer-based EM simulation and software tools (e.g., HFSS and FEKO)
  • Employed specialized microwave equipment (e.g., network analyzer, spectrum analyzer, far-field anechoic chamber) to test and measure the performance of microwave devices and antennas
  • Utilized milling machine and layout software to fabricate prototype planar microwave antenna designs
  • Written and contributed to several research reports and technical documentation for a variety of sponsored-based projects
  • Composed and presented briefings at numerous meetings to the sponsoring agencies
  • Led and collaborated with team members across a wide range of research and development projects spanning across many areas of expertise.

Additional Professional Initiatives

Broadening participation

Dr. Roach recognizes that he has an opportunity to make a difference. In addition to what his technical expertise allows him to contribute to the technology and engineering workforce, he also embraces the mission that ensures fair and equal opportunity for all in science, technology, engineering, and mathematics (STEM). Whether it is in higher education or in the science and engineering workforce (e.g., industry, education, and government), research illustrate the existing disparities for underrepresented groups within the STEM fields compared to majority groups. For example, the 2016 Science and Engineering Indicators (SEI) report prepared by the National Science Foundation highlight that the gap in educational attainment at the bachelor’s level between young minorities and whites continues to be wide[1]. In addition, despite recent increases in participation by women and by racial and ethnic minorities in science and engineering (S&E), both groups remain underrepresented in S&E compared to their overall labor force participation[2].

Dr. Roach has had and continues to have a strong desire and willingness to engage in activities that contribute to broadening the participation of underrepresented groups in STEM. Resulting from his own experiences, it is evident that there is significant value in this type of service. As an engineer in the workforce, he firmly believes that he can be a conduit to the STEM workforce for talented, well-qualified student scholars and professionals from diverse and underrepresented backgrounds. There exist many paths forward to engage himself in these initiatives. He is strongly committed to this path forward, his past educational and work experiences assure him of this.  He desire to place himself in an environment where he can achieve his career and life goals while supporting the mission of the organization.

[1] https://www.nsf.gov/statistics/2016/nsb20161/#/report/chapter-2/undergraduate-education-enrollment-and-degrees-in-the-united-states

[2] https://www.nsf.gov/statistics/2016/nsb20161/#/report/chapter-3/conclusion

Service in the workforce

Over Dr. Roach’s academic and professional career, he has learned that teaching comes in several forms beyond lecturing – namely leadership and mentoring. Students have high expectations of the professor’s role both inside and outside the classroom. This only signifies that best practices should be put toward what is best for the students; guiding them not only to succeed in their academic career, but providing them the mental and technical capabilities to be reputable engineers in the workforce and in society post-graduation. This aspect of mentoring and leadership in the academic setting has a very similar place in the professional workforce – an environment in which one is willing to share knowledge amongst co-workers and having the openness to accept informed input from them.

As Dr. Roach progresses in his career, he aspires to hone further into his craft with continuous dedication, practice, and effort. In addition to this career endeavor, he also seeks to inspire (and be inspired) by taking a more consciousness role in facilitating a more collegial environment via mentoring and leadership within the workplace.   After all, it seems only fitting that such an environment fosters a more productive and fun work/life experience for all.