Eric Eppley Email & Phone Number

Arlington Hts., Illinois

Schaumburg, Illinois

• Designed, developed, and tested a PLL-based high-stability reference circuit that incorporated both a VCTCXO and VCOCXO as possible reference options interfaced to an ADF4001 integer-N synthesizer. Highest stability was achieved through switchable GPS or external TRAK Box inputs to the PLL’s reference input. Optimized the loop filter to maintain noise characteristics of the PLL controlled VCTCXO. • Architected and system analyzed high-spec, dual-performance UHF (400 – 527 MHz) receiver for two-way radio-based infrastructure systems. Design was built around a complex, custom zero-IF / VLIF back-end IC.• Specified all critical receiver component requirements for dual-performance receiver including custom mixers, LNAs, RF switches, and crystal filters. Worked with numerous vendors to obtain parts capable of meeting line-up analysis parameters.• Determined unique method for achieving two-tier, adjustable adjacent channel selectivity (ACS) and intermodulation (IM) performance within the same receiver.• Generated spreadsheets for analysis of all performance aspects of the receiver including sensitivity, receiver spurious, ACS, IM, and mixer spurs. • Redesigned IF line-up for high-tier receiver to replace fundamental-mode crystal filters that caused IM and ACS degradation due to sporadic contamination. Optimized AGC of back-end VLIF IC, achieving best ACS and BER performance across on-channel power.

Schaumburg, Il

• Accountable for design, architecture, and initial evaluation of fractional-N based synthesizer for department’s first-ever analog / digital mobiles and repeaters (XPR series) for VHF, UHF, and 800 MHz bands.• Designed and evaluated different approaches to achieve best cost and performance tradeoffs for implementing receiver frequency generation unit, including very low-noise op amp-based loop filters interfaced to state-of-the-art commercial fractional-N synthesizers; use of low-steering line voltage PLLs dictated need for inclusion of a very low-noise op amp in the loop filter to achieve wide tuning-voltage range while maintaining low VCO Kv for optimal phase noise.• Developed, tested, and wrote 70+ receive and transmit detailed test procedures, including step-by-step test equipment settings, enabling testing of 1st digital transceiver (XPR) developed in the department.• Developed test procedures and test patterns for verification of system software / hardware timing for various repeater and mobile modes of operation.• Resolved a major problem in the synthesizer / VCO block regarding poor modulation flatness over temperature by creating a software look-up table for modulation balance correction versus temperature.• Designed, implemented, and tested receiver for 700 MHz mobile two-way radio. Resolved field problem of LNA failure from high, nearby transmitter power.• Designed and developed synthesizer, battery charger, dc regulators, transmitter, and detailed timing and current drain analysis document for multiple operational modes of two portable handset versions in an in-building 1900 MHz based communication system.

Bachelor Of Science (Bsee), Electrical Engineering

Activities and Societies: Member Eta Kappa Nu

Master Of Science (Msee), Electrical Engineering