Expert Details

Expert in Antenna design, EM modeling (CST, HFSS), Satellite Communication & Technology, RF/Microwave design

Expert ID: 725352 California, USA

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Expert has 20+ years in the RF/antenna/communications engineering field, including design of RF solid-state power amplifiers, airborne radar warning receiver systems, wideband satellite receivers, payload engineering, end-to-end satellite communication systems analysis/simulation, waveform development (M-PSK, M-QAM). Expert worked on a 60 GHz point-to-point radio development where he designed the coplanar waveguide antenna with hemispherical anti-reflection ceramic shell and performed the system design including modulation, spectral and filter analysis, modulation index (FSK), spectral emissions mask and specification of filters. Expert performed end-to-end modeling/simulation and requirements analysis for the MUOS mobile satellite system, which uses a Wideband CDMA waveform based on the 3GPP standard. Expert has performed RF/microwave system level design of payloads and transceivers, including cascade analysis of linear, intermodulation, thermal and phase noise distortion, dynamic range, intercept point, gain and noise figure; link budget analysis, and Bit Error Rate performance. Expert is proficient in use of software simulation tools for satellite system and RF design, including Satellite Tool Kit (STK), Matlab/Simulink, SPW, Agilent Advanced Design System, Eagleware/Genesys, AWR Microwave Office and Visual System Simulator, CST Microwave Studio, and Ansoft HFSS. Expert possesses excellent verbal and written communication skills, including technical proposal writing, technical reports, and presentations.

Expert performed waveform simulation/analysis using Agilent ADS for SONET 10 Gbps communications link to ascertain BER vs. Eb/No performance including impact of switch/compensator network and timing jitter in the receiver. Expert consultant for legal case involving trade secrets related to RF/microwave modules used for C-IED applications.

Expert may consult nationally and internationally, and is also local to the following cities: Los Angeles, California - San Diego, California - Long Beach, California - Santa Ana, California - Anaheim, California - Riverside, California - Glendale, California - Huntington Beach, California - San Bernardino, California - Chula Vista, California

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Year Degree Subject Institution
Year: 1987 Degree: BS Subject: Electrical Engineering Institution: San Jose State University
Year: 2020 Degree: MS Subject: Electrical Engineering Institution: Arizona State Univeristy

Work History

Years Employer Title Department Responsibilities
Years: 2013 to Present Employer: Undisclosed Title: RF Communication and Antenna Systems Engineer Department: Responsibilities: Modeled and analyzed BLOS communications systems. Modeled antennas and analyzed as-installed antenna performance.

Used STK to model access to Iridium LEO constellation from (a) fixed ground location (b) aircraft to determine
link dropouts and link margin as a function of look angle and attitude rate. Used STK to model BLOS communication link performance for forward and return link via TDRSS satellite. Modeled phased array transmit and receive antenna gain using Matlab antenna gain plugin script in STK as a function of air vehicle (AV) body coordinates. Performed link budget analysis. Supported UCLASS for Payload and Communications aircraft installed antenna performance and co-site analysis. Reverse-engineered and modeled supplier antennas (conformal, array, cavity slot, spiral, sinuous) using CST, HFSS, and FEKO and integrated models onto AV for analysis of installed farfield radiation patterns and coupling between antennas. Used Savant to analyze installed antenna performance above UHF using equivalent current source antenna representation on aircraft.
Years: 2010 to 2013 Employer: DRS Technologies Title: Prin RF Systems Engineer Department: Responsibilities: Designed airborne Direction Finding array in 30-3000 MHz range, analyzed DF system performance, modeled as-installed DF array performance, designed wideband resistively loaded blade antenna.

R&D individual contributor and project lead to develop Ka-Band SATCOM On-The-Move vehicular terminal including: EM modeling of reflector using CST, plotting of antenna gain to determine compliance with WGS and FCC EIRP spectral density requirements; link budget analysis; integration/test. Performed analysis and application to ARSTRAT for WGS certification for X- and Ka-band OTM terminal. Cascade gain/noise figure analysis, system noise temperature and G/T analysis for X, Ku, and Ka-band OTM terminal. Vendor oversight and specification of Ka-band Block Upconverter (BUC), Block Downconverter (LNB), and SSPA. Investigated modulation/coding performance tradeoffs and adaptive coding and modulation (ACM). Key business development point of contact for COTM customer technical questions pertaining to link capacity, terminal performance, antenna requirements, modulation/coding, etc. Global Broadcast Service shipboard satellite terminal wideband RF front end receiver cascade and intermodulation analysis to determine dynamic range with customer-defined dense signal interference environment. Modeled using Simulink and analyzed shipboard satellite dual antenna system employing spatial diversity and equal gain combining to improve G/T. EM modeling of log periodic dipole array antennas for electronic warfare jammer application using CST. Propagation modeling of jammer using HTz Warfare to determine jammer-to-signal ratio as a function of number of signal sources and frequency. Performed antenna coupling and direction finding (DF) receiver sensitivity and interference analysis. Synthesized DF antenna array for airborne direction finding (DF) application using Matlab. Simulated resistively loaded blade monopole antenna performance and DF array placement on aircraft solid model using CST. Designed man-portable tactical direction finding antenna system utilizing a 4-element array and Butler matrix. Specified antenna and wideband downconverter for a .5-20GHz portable interception equipment Signals Intelligence (SIGINT) system.
Years: 2006 to 2009 Employer: General Dynamics Title: Sr. Lead Engineer - Systems Department: Advanced Information Systems Responsibilities: Expert designs RF/microwave transceivers for satellite payloads, performing cascade system and BER analysis, link budget analysis.

Design, research and development of surveillance satellite payloads and systems, including detailed payload RF design, end-to-end system BER analysis using Matlab and AWR Virtual System Simulator. Performed phase noise vs. modulation type analysis, coded closed-form expressions for BER vs. Eb/No and phase noise in Matlab for
BPSK, QPSK, 8PSK, MSK, GMSK modulation types. Performed RF front end cascade and spurious analysis for three-stage superheterodyne receiver, specified RF components, tested prototype. Led conceptual design trade study for UHF handheld satellite communications terminal including antenna trade study, communication link
performance as a function of data rate, modulation/coding, and environment (urban, rural, open), and high efficiency RF SSPA architecture. Modeled candidate antennas using EZNEC and CST, prototyped antenna using radio mock-up and measured farfield radiation pattern and gain in anechoic chamber. Researched high
efficiency SSPA design approaches and topologies. Summarized study results and presented to internal and external customers. Conducted a Monte Carlo analysis to determine phase amplitude requirements for a beam former consisting of 90 and 180 degree hybrid couplers and power dividers. Contributed to a proposal for a
satellite-based sensor system; modeled sensor antenna patterns, link analysis, multiple access trade (time/code/frequency domain).
Years: 2001 to 2005 Employer: Lockheed Martin Title: Sr. Staff Engineer Department: Integrated Systems & Solutions Responsibilities: Expert designed and modeled satellite communications systems, both mobile and fixed.
Government satellite communications systems engineering, simulation, analysis, and requirements development. Led team of PhDs to develop an end-to-end waveform channel simulation model using Matlab and Agilent ADS (3GPP library) for the Mobile User Objective System (MUOS), a UHF/Ka-band double-hop analog/digital
geosynchronous mobile communications satellite system employing a 3GPP-like W-CDMA waveform. For Base-to-User (Ka up/UHF down) investigated impact of nonlinearities and multiple access interference (MAI) on BER performance as a function of # of carriers and orthogonal codes. For User-to-Base (UHF up/Ka-down) investigated
digital multiplexing, channelization, and impact of external and legacy interference. Developed B2U hardware-in-the-loop simulation employing Ka-band TWTA and prototype UHF SSPA using ADS to generate waveforms, measured BER, EVM, ACLR, and Peak Code Domain Error. Developed communications subsystem specification
for NPOESS weather/scientific satellite: performed EM self-interference analysis and specified RF transmit/receive filter requirements. Principal Investigator for Transformational Communications Satellite (TSAT) Comm-On-The-Move R&D project to develop satellite and terminal communication system requirements for tracking, pointing, acquisition, and error/blockage mitigation while transmitting to and receiving from land-based mobile terminals at T-1 rates; EHF channel modeling, waveform modeling using Simulink, FEC coding, link analysis, and mobile
terminal antenna gain and acquisition/tracking requirements. Principal Investigator for bandwidth efficient modulation R&D project. Principal Investigator for high rate free space optical communications R&D project. Investigated error mitigation vs. FEC coding and interleaver depth. Contributed to Airborne Lasercom Terminal Architecture proposal: developed optical and RF architectural requirements, SONET/SDH networking interfaces,
Family of Advanced Beyond Line of Sight Terminal (FAB-T) terminal interfaces, participated in TSAT working groups. Designed, developed and tested wideband satellite communications receiver subsystems for earth terminals from L-band through Ku-band. Designed a 3-GHz QPSK test modulator including RF system design and local oscillator
phase noise analysis, specification of RF components, design of DC-1GHz wideband amplifier module.
Years: 2000 to 2001 Employer: Agilent Technologies Title: Sr. Hardware Engineer Department: Responsibilities: Expert participated in the design of a 60 GHz radio link.

New product design and development for point-to-point "last mile" 60 GHz full duplex radio utilizing FSK waveform. Used HFSS to model and analyze a half-wave dipole, coplanar waveguide launched dual slot antenna with ceramic lens to focus EM wave. Conducted geometry parametric studies to optimize gain, pattern, sidelobes, and sub-harmonic rejection (of LO reference leakage). Measured prototype antennas in lab using VNA and rotating standard gain horn. Exported EM near-field data for propagation analysis through farfield lens using physical optics program. Modeled RF/IF modulation chain using Agilent ADS to determine FM modulation index and filter requirements to meet jitter and FCC transmit emissions specification.
Years: 1997 to 2000 Employer: Space Systems/Loral Title: Sr. Engineering Specialist Department: Responsibilities: Expert designed satellite payloads and analyzed and simulated satellite systems performance.
Years: 1995 to 1997 Employer: ArgoSystems Title: RF Lead Engineer Department: Responsibilities: Expert performed RF system/circuit design for Global Broadcast Satellite airborne burst receiver demo, redesigned C-band FMCW aircraft altimeter system, wrote test requirements for RF front end, including microwave tuner and frequency discriminator, for Electronic Support Measures (ESM) Airborne Warning and Control System (AWACS).
Years: 1992 to 1995 Employer: Stanford Linear Accelerator Title: Sci/Eng Associate Department: Responsibilities: Expert designed a klystron amplifier test station.
Years: 1989 to 1992 Employer: Lockheed Martin WDL Title: Engineering Specialist Department: Responsibilities: Expert designed wideband satellite communications receivers.
Years: 1988 to 1989 Employer: Microwave Modules & Devices Title: RF Design Engineer Department: Responsibilities: Expert designed RF solid-state power amplifiers.

Career Accomplishments

Associations / Societies
IEEE Antennas & Propagation Society
IEEE Microwave Theory & Techniques Society
IEEE Communications Society
Licenses / Certifications
Active DoD Top Secret with current SSBI;
TS/SCI w/polygraph (reinstatement in process)
Awards / Recognition
STAR Employee Achievement Award for Phase Noise vs. Modulation Type analysis
Employee Recognition Award for Globalstar Spectral Emissions analysis

Additional Experience

Expert Witness Experience
2009 Consultant for plaintiff in case involving theft of proprietary information relating to microwave circuitry used in counter-IED applications. Submitted report to client. Not required to testify.
Training / Seminars
Attended short courses in Antenna Engineering, Antenna Modeling & Simulation, and Phased Array Antennas at Georgia Tech.
Marketing Experience
20+ years experience in the satellite communications industry, both commercial and military
Other Relevant Experience
BSEE+20 years RF, communications & EW/SIGINT systems design/analysis/modeling experience.
Active DoD Top Secret, current SSBI (TS/SCI with polygraph reinstatement in progress).
Enrolled in Naval Postgraduate School MSEE EW/Sensor Systems Engineering option.
Experienced with system architecture design, requirements analysis, performance optimization.
Experienced with simulation/synthesis simulation tools (Matlab/Simulink, ADS, MWO, Eagleware, CST).
Knowledge of digital modulation techniques and complex IQ signal processing for comm & EW.
Design knowledge of antennas, receivers, up/downconverters, tuners, PLLs, frequency synthesizers.
Excellent technical (proposal) writing and communication/presentation skills.

Fields of Expertise

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