Compact ESP32 & SIM868 PCB Design

I need a production-ready CAD layout for a single, ultra-compact PCB that merges two existing boards into one tidy footprint. The board’s primary role is data communication, and I’m relying on a SIM868 module for the cellular link while an onboard ESP32 handles processing and Wi-Fi/Bluetooth expansion down the road.

Key electrical notes: everything must run from a 3.72 V rechargeable solid-state micro-battery, so clever power routing, low-drop regulators and battery-safe charging logic are crucial. Keep component selection surface-mount and as low-profile as possible; the goal is the absolute smallest form factor without compromising RF integrity for either the ESP32 or the SIM868.

Deliverables (all in CAD-ready, manufacturer-friendly formats):
• Schematic with reference designators and net labels
• Optimised multi-layer PCB layout, impedance-matched RF traces and antenna clear-zones
• Gerber/ODB++ files, drill files and pick-and-place data
• BOM with footprints, part numbers, and suggested suppliers
• Assembly drawing and brief design notes explaining power distribution, battery charging scheme and RF considerations

Acceptance: files must import cleanly into KiCad/Altium, pass a standard DRC at 6/6 mil trace/space, and fit inside a 25 mm × 30 mm keep-out. If you can hit the size while meeting the 3.72 V power spec and maintaining good cellular signal quality, the job’s complete.