RF Test & Validation Engineer (WiFi/EMI)

WILSON FOK

408-***-**** ******@*****.***

PROFESSIONAL EXPERIENCE

MICROSOFT INC., Redmond, WA Apr-2025 – Jun-2026

RF Design Validation Engineer (consultant), Xbox Wireless Group

RF Design Validation Engineer (consultant), Xbox Wireless Group

Antenna testing using MVG system for various DUT designs from development team

Supported antenna team for their antenna characterization by running Bluetest WiFi TRP as well as CMW270 signaling mode on a DUT and provided them with power measurement.

Supported RF validation through RF parametric temperature tests using Lightpoint for new gaming controller development.

Perform passive EMI scan and correlate active TIS data

Setup and debug tests for prototype for new game console development

Automated scripts, commands using Python, .bat, SCPI, and with the aid of Microsoft co-pilot.

AMAZON, INC, Redmond, WA Jan-2025 – Mar-2025

Phased Array Antenna Calibration Engineer (consultant), Kuiper Project Antenna Team

MICROSOFT INC., Redmond, WA Mar-2023 – Jun-2024

RF Design Validation Engineer (consultant), Xbox Wireless Group

Antenna testing using MVG system for various DUT designs from development team

Supported antenna team for their antenna characterization by running Bluetest TRP as well as CMW270 signaling mode on a DUT and provided them with power measurement.

Supported RF validation through TIS & TRP tests using Bluetest chamber for new gaming consoles development.

Perform passive EMI scan and correlate active TIS data

Debugged and validated prototypes and factory-built trial-run game consoles.

Automated scripts, commands using Python, .bat, SCPI, Selenium (for web browser interaction), etc. from time to time as new test challenges arise.

META Sunnyvale, CA

Sep. 2021 — Feb. 2023

RF Desense Validation Engineer, VR Desense Engineering Group

Worked on WiFi 2.4G, 5G, 6E, 7G and LTE desense validation, both signaling and non-signaling, for various VR projects including glasses with noise generated by RGB, SLAM, tracking & IR cameras, CPU, memory aggressors, etc.

Conformal shielding evaluation using API EM field scanner

MICROSOFT INC., Redmond, WA Nov. 2019 – Sep. 2021

RF Design Validation Engineer (consultant), Xbox Wireless Group

●Worked both remotely and from the lab with a cross-functional team for the recently launched Xbox Series S and Series X game consoles.

●The bulk of my work involved RF design validation (both conducted & radiated) of our consoles with focus on WiFi desensitization effort. The overall task was substantial due to the performance evaluation of a number of different cost-reduction hardware configurations and added console features on two new Xbox models developed in parallel.

●Coded python scripts to automate the validation process as much as possible to facilitate “WFH” remote RF evaluation of a large sample size of DUTs.

●Contributed to the planning and defining desense RF design requirement matrix for Xbox consoles under all supported operating modes which included Blu-ray playback, 4K video streaming, and with connected devices e.g. USB3 flash drive or accessory controller.

STARRY, INC., Boston, MA, Feb. 2018 – Nov. 2019

Principal RF Engineer, Engineering Team

●Worked in the organization for the development and manufacturing of mmWave test equipment for fixed-wireless internet services.

●Defined Design Verification Test (DVT) and Production test cases and test specs for our 40GHz, mmWave transceiver

●Designed RF system for performance validation of cascaded NF, IP3 analysis of our mmWave transceiver prototypes

●Contributed to the bring-up and debug of the above single-chain 40GHz transceiver

●Developed automated DVT, python scripts, and test system for effective test of our 40GHz transceivers. Test cases included NF, conversion-gain, TOI, P1dB, Psat, inter-port isolation, Tx On/Off switching time, spurs search, Tx power, phase noise, synth locking, EVM, for both Tx and Rx.

●Defined and supported, based on my previous patented curve fitting idea, the implementation of our transceiver calibration algorithm across mmWave channel frequencies, and over the temperature range, for efficient memory usage and near instantaneous operating response time

●Participated in mmWave transceivers schematic and PCB layout reviews and provided recommendation

●Evaluated 40GHz standalone RF blocks such as RF detector, directional coupler, PA drivers, passive and active mixers, SIW, edge coupled filters, etc.

●Collaborated with team for the development of both 40GHz and 24GHz design requirement document.

●Resolved RF related issues to clear some bottlenecks on existing mmWave product lines

MICROSOFT INC., Redmond, WA May 2016 – Oct. 2017

RF Design Validation Engineer (consultant), Xbox Wireless Group

●Worked with a cross-functional team for game consoles Wi-Fi desensitization effort.

●Configured far- and near-field setup in anechoic chambers and manually executed radiated emission test to locate any in-band spurs, and broadband noise that may potentially cause channel desense in the dual-band, 2.4G & 5G, consoles. Measurement included ambient noise floor with the use of an external pre-amp, leakage, polarization, and path loss calibration, etc. Optimized spectrum analyzer setting for sensitivity vs. measurement speed. Measured data were analyzed and correlated with TIS measurement in reflective chamber to further desense investigation.

●Defined automated EMI test app requirements and worked closely with SW engineers for its development. Considerable time saving for both radiated EMI testing and data post-processing has been realized with its deployment.

●Carried out OTA TRP, TIS, RvR (TDP, UDP throughput) characterization of console’s network and accessory radios (dual-band Wi-Fi, 2x2, receive diversity) using Bluetest reverberation chamber and performed routine chamber calibration.

●Contributed to devising debug methodologies and their respective debugging tools, participated in desense debug and bug-fix validation effort to ensure consoles meeting receiver sensitivity with good margin in both manufacturing as well as lab environment.

QUALCOMM INC., San Jose, CA 2011 – 2015

Staff Engineer, Systems Engineering Group

●Provided technical support through RF simulation and bench testing for debugging RF, PCIe, and USB issues throughout the product development cycle including silicon bring-up, board level reference design which included impedance matching (with port extension) for antenna and LNA and manual PA stability load pulling, manufacturing support, Wi-Fi performance test, etc.

●Developed reference design boards for 802.11a/b/g/n and successfully by:

●implementing the concept of self-calibrating the transmit power with greatly increased accuracy and considerably decreased calibration time

●optimizing Tx chain gain/IP3 distribution for power compliant EVM

●optimizing Rx chain gain/IP3 distribution, and crystal clock buffer drive level to mitigate self-blocking

●designing, simulating, and fine tuning the LC section, balun for receiver sensitivity and transmit power.

●LC filter design and optimization to mitigate GSM mobile interference to Wi-Fi chip’s PCIe ref-clock.

ATHEROS INC., San Jose, CA 2007 – 2011

Principal Engineer, Systems Engineering group

●Supported product management team and resolved numerous RF, PCIe, USB related design issues such as desensitization, power supply noise, etc. on customers’ system boards using Qualcomm 802.11 chips.

●Participated in PCB layout design reviews and provided RF layout design recommendation.

●Wrote and obtained customer approval for the requisite test plans for antenna diversity, conducted RF, rate vs. range, and design analysis documentation.

●Successfully executed all requisite electrical, mechanical and reliability tests with OEM partners

●Evaluated and optimized USB PLL jitter, reference spurs, with loop parameters to ensure eye diagram compliance.

●Successfully brought up the hardware for a 2.4GHz BT demo reference design board that included schematic capture and supervised PCB layout, RF performance optimization, debug, air interface and OTA functional testing including 10-meter audio test. Also optimized BT headsets for customers and performed current consumption, RF parametric & OTA functional tests.

UTSTARCOMM INC., China 2001 – 2007

Principal RF Engineer, Wireless Terminals BU

●Developed many models of low cost PHS, and dual modes GSM/PHS, CDMA/PHS, GSM/CDMA handsets for major telecom operators in China. Defined various RF IC architectures and worked with multiple RFIC design houses for design requirement, RFIC samples performance reviews, etc. to continuously drive down the BOM, improve handset yield, add or remove handset features, etc.

●Conducted IC samples evaluation, supervised PCB layout, and integrated the entire RF transceiver section including front-end and inter-stage impedance matching, and system debug etc.

●Conducted co-existence studies that resulted in a dual mode handset solution based on antenna isolation and filtering; performed handset antenna simulation

●Supported marketing on requirement documents, and provided prototype handsets samples.

OTHER PREVIOUS RF EXPERIENCE

AT&T Bell Labs, Lucent Technologies, NJ 1992 – 2001

MTS, Consumer Products BU

●Board level RF development for CDMA, TDMA & EAMPS terminals.

●Designed the RF board for a handheld EAMPS analog cell phone and supported its pilot run up to mass production.

EDUCATION

MS, Electrical Engineering, Monmouth University, NJ, US

●Project thesis – Interference mitigation for CDMA terminals

BS, Electronic Engineering, University College of North Wales, Bangor, UK

●Project dissertation – Precision demodulator for microwave network analyzers

Certificate in VLSI, University of California, Santa Cruz, US

●Projects – 5GHz VCO, and 5GHz LNA RFIC designs, simulation and complete with project reports

GRANTED PATENTS

(Co-)inventor of 6 patents

SIMULATION and SCHEMATIC & LAYOUT TOOLS

SpectreRF, Liberate IBIS modeling tools, PSpice, PADS, HFSS, Optenni Lab, MATLAB, Allegro, Altium

PROGRAMMING EXPERIENCE

Perl, Python scripting, Linux, C and C++, LabVIEW, mbed device programming

TEST EQUIPMENT

VNA, VSA, spectrum analyzer, Litepoint IQxel-MW, high speed scope, NF meter, modulation domain analyzer, Anritsu Bluetooth Test Set, audio analyzer, USB & PCIe protocol analyzers, sig-gen, function-gen, Wireshark Packet Sniffer, Bluetest reverberation chamber test system, R&S CMW 270, Anritsu MT8862A WLAN Tester, R&S- FSVA40, FSW

LANGUAGE

English, Cantonese, Mandarin

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