A few years back, [Roman Black] experimented with the cheap RF modules you can find on auction sites and from surplus electronics vendors for only a few dollars, and wrote up his findings.

The board that drives the Xbox 360’s status light ring also includes the RF module that wirelessly connects the controllers. He wired this up to his Raspberry Pi using the GPIO header.

Targeted for the smart home, this design leverages two PIC MCUs that use a wireless RF transmitter ... intended for smart-home systems. The RF modules (PT2262) used in this setup are available ...

The antenna is connected directly to the 50Ω RF pin. The RC1700HP-MBUS module is certified for operation under the European radio regulations for license-free use and is CE marked. The module is ...

the RF power amplifier. The industry trend to shorten time to market is to decrease system complexity by integrating transmitter and receiver functionality into a single front-end module (FEM) and ...