Use cheapest sensor and RF Explorer Spectrum Analyzer with Sniffer to understand modulation, transmission techniques and antennas
Project of RC Switch - https://github.com/sui77/rc-switch
RF Explorer - www.rf-explorer.com
Project Sniffer - http://j3.rf-explorer.com/menu-the-news/173-rf-explorer-sniffer-public-beta-available
Simulate a Telecontrol as garage controller. Example in ebay:
