Operated, maintained, repaired, and refurbished multiple wind-profiling doppler speed measurement radars, as well as developed the prototype next generation system to replace said radars. This involved the reverse-engineering of current radar systems in order to understand the RF driving circuitry, antenna design philosophy, and beam steering methodology, such that I could design and build a full drop-in replacement system to accommodate legacy code while capitalizing on modern developments in RF technology. Furthermore, due to budget constraints, extra effort was made to minimize cost and maximize repairability to ensure the system could be passively repaired and upgraded to avoid obsolescence.

Within the full 915[MHz] radar design I designed, simulated, tested, and fabricated:

• A fixed-point Planar Active Electronic Steerable Antenna

  • The 32 Coaxially Collinear Antenna Elements within said array

    • The 32 Matching and Filtering Networks for every element, also balancing the load equally to each arm of a 2-arm element. Soldered via 1206 component based custom tri-pi matching nets

    • Hand fabricated all 32 elements from cheap LDF4-50A coax. Additionally developing fabrication techniques and material capability studies with said armored cabling for future fabrication by in-house technicians. So, 64 hand soldered 1m long coaxial collinear antennas, making 32 elements with 32 matching networks, all hand-assembled by myself due to staffing restrictions, and costing under $1000 for the entire antenna (excluding frame and rf control system). Which replaced an antenna quoted by Vaisala for $50k (including frame).

  • 2m x 2m wind-profiler’s frame, housing, and environmental protection

  • Ensured

• The beam-steering control circuitry adapted from legacy physical switching control systems from the old vaisala system used, saving thousands on additional controller expenses and design time.

  • Hand phase-matched all aspects of the RF drive to all 32 elements, keeping linear switching to swap between 4 cardinal directions and vertical, along with a planar XY steering mode, never implemented due to cost.

  • Verified integration with legacy system for antenna steering measurements within custom range.

• The Transmitter and Receiver section layouts

  • Signal conditioning, mixing, filtering, and monitoring

  • Added extra feedback loops to monitor and avoid faults with power surges, RF amplifier failure, or temperature.

• The full breadth of design and repair/maintenance documentation for the CoCo electromagnetic design, the array theory driving the simulations, the beam steering implementation, the radar operation and antenna characterization.

• The Free-Space automated antenna testing range to validate antenna array capability

  • Automatic range finding with UWB modules, that then report variable distances to an RF custom pinger that broadcasts CW with a half wave dipole.

  • Controls automatic motor positioning and angle management via custom python code

  • Interfaces with a Keysight Signal Analyzer for the full measurement via gpib or ethernet

  • Fabricated and characterized the antenna under test, array under test, and testing Half Wave Dipole baseline antenna, utilized by this system.

  • Eventually modified system to go from single element support to full array spinning and pattern measurement.

  • Compared and verified design capability from real measured results with the simulations created, creating a roadmap for future improvements and developments in both single elements and array.

• Presented a poster at the AMS Radar Conference over the design and integration of low cost yet modular phased arrays. Motivated by lackluster funding of weather research to provide the layout of the planned scalable AESA COCO array

In regards to the 449[MHz] Radar I maintained, updated, and operated:

• Redesigned and fabricated High Power Amplifier bias/measurement boards to fix issues in spontaneous combustion.

  • From design to bring-up, worked to optimize additional mitigation circuits to flatten spikes of RF back-flow that was effecting other component circuitry.

  • Reworked, tuned, and optimized radar layout for updated modern components.

  • Investigated possible cost-reductions or size-reductions, implementing when practical.

  • Designed and simulated an alternative COCO antenna array in case of 915 system success.

• Wrote an entire testing and repair guide for the repair of custom RF circuitry found within the 449 Radar, providing the ability to finally reliably repair the high power amplifiers regardless of engineer presence. Saving us thousands on Amplified costs as instead of buying 2k amplifier replacements, a technician can simply perform a chipset swap on the main transistor that always exploded.

• Re-wired the supply system, solving the vast majority of spontaneous explosions caused from power level mismatch.

• Re-arranged the full RF layout in order to tune the system to perform as a full phased array system, before it had been phase mismatched and operating sub 50% of its capability.