HackRF
Low cost software radio platform
...Designed to enable test and development of modern and next-generation radio technologies, HackRF One is an open-source hardware platform that can be used as a USB peripheral or programmed for stand-alone operation. HackRF One has an injection-molded plastic enclosure and ships with a micro USB cable. An antenna is not included. ANT500 is recommended as a starter antenna for HackRF One. HackRF One is test equipment for RF systems. It has not been tested for compliance with regulations governing the transmission of radio signals. You are responsible for using your HackRF One legally.