AgTech RF Prototype to Production PCB in 3 Spins

RF prototype turned into a clean, production-ready PCB: ~$460 BOM saved per unit and 95 % faster assembly, functional by the second board spin.

Simon Bourguigne

6/26/20251 min read

Client & Need

Early-stage AgTech company building a remote-sensing device. They needed to replace a connectorized RF prototype plus dev-kit wiring with a single, manufacturable PCB that cut cost and assembly time.

Context & Challenge

The lab setup used dev boards, flying wires, 16 SMA connectors, and a ~$300 off-board RF switch. Assembly took hours and was error-prone. The RF chain ran near thermal noise with >70 dB gain, so isolation, grounding, and controlled impedance were critical.

Process

  • Architecture & layout: General design, stack-up selection, controlled impedance, clean partitioning, via fences, guarded returns.

  • Re-Spin 1 (after bring-up): Diagnosed out→in coupling with temporary shields, lock stack-up and Z₀, partition RF blocks to break paths, then verified isolation and performance in the enclosure.

  • Re-Spin 2 fix: Increased spacing and tighten ground/guards to remove manual shielding. Fix assembly with defined reflow and QA. Swaped risky parts. Cleaned minor layout for repeatable yield.

  • DFM/validation: Test points, quick RF checks, and assembly guidance for repeatable builds.

Results

  • BOM: ~−$460 per unit (≈411,129 sats) by integrating the RF switch and removing excess plumbing.

  • Assembly: hours → minutes

  • Timeline: Functional on the second version; later tweaks were minor.

  • Status: Continued engagement to lead hardware and firmware to market release.

Services

PCB design, RF lab testing, vendor coordination.