Study guide — what to focus on

This module is curated — the teaching is a top free course (linked in the card above); our job is to point you at the right things, make you prove it, and certify you.

The plan

1. Watch the course (the card above). You don't need to memorise it — aim to understand the ideas below.
2. Focus on these — they're what the check tests and what you'll use for real:
   • Wavelength & frequency — they're inverse; higher frequency means shorter wavelength.
   • The dB / dBm math — 0 dBm = 1 mW, +3 dB ≈ double the power, +10 dB ≈ 10×; received levels are negative dBm, and closer to 0 is stronger.
   • Antennas — gain (dBi) focuses energy, it doesn't add power; a directional antenna trades coverage for reach.
   • Range vs. frequency — lower frequencies travel farther and punch through walls better than higher ones (why LoRa lives in sub-GHz).
   • Modulation — data rides on a carrier by varying its amplitude, frequency, or phase.
   • Module trade-offs — Wi-Fi (2.4/5 GHz, fast, short range, power-hungry), BLE (short range, tiny data, very low power), LoRa (kilometres, tiny data, very low power). Range, data rate, and power are the three you trade against each other.
3. Prove it in Forge (next section) — pick the right radio for a real device.
4. Take the K-Check to earn your certificate.

Why this connects to building real products

Every connected product you design in Forge has to get its data out, and that choice is an RF decision. Knowing the fundamentals lets you reason about the trade-off instead of guessing: a wearable that talks to a phone wants BLE; a camera that streams wants Wi-Fi; a battery sensor out in a field wants LoRa. The same dB math tells you whether a link will actually close — how much antenna gain or transmit power you need for the range you want. Understanding RF is what turns "add a wireless module" into a design decision you can defend.

Time to apply it. The course taught you the range / power / data-rate trade-off; now use it to pick a radio for a real device.

Send the prompt below in Forge Design and watch it reach for a LoRa module — the low-power, long-range choice for a battery sensor that only sends small readings — then wire the radio, antenna, and power into an orderable design.

As you read Forge's answer, connect it back to the course: why LoRa and not Wi-Fi or BLE here? What does the antenna choice do to your range, and roughly what dBm link would you need to close? That reasoning — matching the radio to the job — is the whole point.