Hardware

  • PCB schematic & layout: high-frequency RF & mmWave, analog and high-speed digital interfaces
  • Wireless: 2.4/5 GHz Wi-Fi, BT/BLE, NFC, cellular (GSM/UMTS/LTE, 2G/3G/4G/5G), GNSS (GPS, GLONASS, multi-band, RTK/corrections, etc.), V2X (DSRC, C-V2X), 900 MHz ISM, etc.
  • Digital: FPGA/MCU/SOC, DDR, NAND/NOR flash, Ethernet, PCIe, USB, SPI, I2C, UART, LVDS/LVPECL, GMSL, CAN/CAN-FD, LIN, etc.
  • Data converters: high-frequency ADCs/DACs, baseband drive & filtering
  • Power management: switchers (buck, boost, buck-boost, etc.), linear LDO regulators, reverse-power & ESD protection, Power over Ethernet, low power modes & sleep/wake cycle, etc.
  • Validation: chip level (RFIC, baseband ASIC, PA/LNA, RF front-end, etc.) and PCBA level (bringup, design validation, unit test, automation/scripting, regerssion, reporting, etc.)
  • Certification: FCC (Part 15b including 15.247/15.407, DFS apporvals, petition process), PTCRB (TRP/TIS OTA mesasurements, antenna radiation efficiency, etc.), MNO/carrier approvals, IC, ETSI, regulatory approvals, etc.
  • Manufacturing: NPI, fixtures (ICT, FCT, EOLT, etc.), testing, automation/logging, line debug, BOM cleanup, etc.

RF & Antenna

  • Frequency translation: architectural trade-offs (direct-modulation vs. IF-based mixing, SSB vs. DSB, etc.), spur analysis & mitigation techniques, LO generation, etc.
  • Gain control: chain optimization between noise/distortion, broadband & high dynamic range, custom amplification & variable attenuation, etc.
  • Amplifiers: discrete transistor designs (LNA & PA), bias networks, ALC circuits
  • Isolation: output matrix, half/full duplex systems, high-speed switching, combining, loopback, power detection & RF triggering
  • Synthesizers: fixed reference (OCXO, VCXO, TCXO, custom solutions, etc.), RF synthesizers (DDS, VCO & YIG based), integer & fractional PLLs, multipliers/dividers/comb generation, etc. Optimize phase-noise, spurious response & tuning time
  • Lumped-lement filters: differing topologies (operating from a few MHz to GHz), ceramic filters (up to tens of GHz), switchable filter banks, varactor-based tunable filters, etc.
  • Transmission lines: microstrip, stripline, coplanar waveguide, via-based transitions, etc.
  • Distributed structures: low-pass/high-pass/band-pass filters in varying topologies (shunt-stub, ladder, edge-coupled, interdigital), broadband directional couplers, Wilkinson combiners, etc.
  • Antenna: resonant dipoles (folded, tapered etc.), loops, patch, slot. PCB (FR4, Rogers, Teflon) & on-chip (Si substrate), loss mitigation techniques. SMT integration, performance optimization & characterization
  • EM simulation: 2-2.5D MOM (AWR Microwave Office & Agilent ADS), 3D FEM (Ansoft HFSS) & 3D FTDT (CST Studio) methods
  • Radar: IF and mmWave conversion, FMCW/chirp, DDS generation, ADC capture, FPGA signal processing
  • Shielding: sheet metal cans & machined/tooled aluminum parts, non-resonant cavities, injection-molded plastics, gasketing & absorbers to minimize leakage and improve isolation
  • Measurements: S-parameter, cross-correlation phase noise, linearity & compression-point, noise-figure, EVM/SNR (bath-tub curve, etc.), synthesizer settling time & accuracy, RF switching speed, intended & unintended radiation, antenna radiation pattern & efficiency, etc.
  • Calibration: direct conversion (IQ/LO offset), channel imbalance, amplitude accuracy, frequency/gain/temperature compensation, etc.

Firmware

  • Wireless: 802.11 PHY/MAC, CSMA/TDMA, rate adaptation, spectrum management, interference mitigation, beamforming, DSP, DFS detection, positioning & triangulation, cellular/LTE management over AT interface, eDRX sleep/wake, etc.
  • Networking: NAT, routing, forwarding, DNS, DHCP, QoS, VPN, IPv4/IPv6, Linux stack, etc.
  • Operating systems: Linux, RTOS, bare metal scheduler
  • Inter-core communication: IPC/RPC messaging, dbus, etc.
  • Drivers: kernel/userspace, polling vs. interrupt-based, peripherals such as display, touchscreen, battery/power management, networking, Wi-Fi/BT/GPS, cellular, UART/I2C/SPI, etc.
  • Filesystems: Linux (squashfs, tempfs, etc.), persistent vs non-persistent data, flash write wear management
  • Bootloaders: SOC, u-boot, memory/CPU usage management
  • Firmware update: delta update, A-B partition/plug-pull safe
  • Cybersecurity: AES-256 signing & authentication, secure boot (bootloader, kernel, rootfs key verification)
  • Build systems: GCC, yocto, buildroot, ninja, make, cmake, etc.
  • Processors: ARM (M-core/A-core types) & ARC processors such as ST STM32, Nordic nRF5, NXP i.MX8, Microchip SAMA, Silicon Labs BG21, NXP KW etc.
  • Debuggers: SWD, JTAG, UART/serial, CAN, etc.
  • C/C++, Pyhton, Java, Verilog, bash/shell scripting, Linux, etc.
  • GIT, JIRA, Bitbucket, code management, release management, branching strategies
  • Test: National Instruments LabVIEW & TestStand, Agilent VEE
  • Data analysis: Python, MATLAB, Maple, FORTRAN
  • Mobile: iOS (Objective-C, Swift, Xcode) & Android (Java, Kotlin, Android Studio)
  • Web: HTML, CSS, PHP, JS, REST API, Amazon AWS (EC2, Lightsail), Laravel, Apache, MySQL, etc.