The concept of software-defined radio （SDR） has been proposed for many years.However，owing to the limitation of integrated circuit design and manufacturing technology，the development of SDR chip technology has been relatively slow for a long time.In recent years，with the rapid development of integrated circuit design and manufacturing technology，SDR chip technology has made significant progress，which effectively promotes the development of radio frequency （RF） microsystems.Firstly，the development history of SDR chip technology is reviewed，and the SDR chip based on the zero intermediate frequency （ZIF） system on chip （SoC） is introduced.Secondly，the architecture of a traditional RF microsystem is compared with that of an RF microsystem based on the ZIF SoC.Thirdly，the design of RF microsystems is analyzed from three aspects，i.e.，prototype design，packaging design，and circuit design.Fourthly，the implementation and integration process of RF microsystems are elaborated.Finally，the future development of RF microsystems is prospected.