xG Technology, Inc. is a developer of technology for wireless communications and spectrum sharing. The company is headquartered in Sarasota, Florida with engineering facilities located in Fort Lauderdale, Florida. xG is a publicly traded company listed on the NASDAQ Capital Market. Its common stock is traded under the symbol XGTI.

xG has created a portfolio of intellectual property that includes cognitive radio, interference mitigation and self-organizing wireless network technologies for mobile services using licensed or unlicensed radio spectrum. The company has commercialized some of these innovations to create xMax®, a private fixed and mobile wireless broadband system that delivers voice, video and data services for residential, business and government users.

xMax currently operates in the unlicensed 900 MHz ISM band, although it has been designed to be programmed for operation in any licensed or unlicensed frequency from approximately 300 MHz to 3 GHz.

The xMax system is designed to allow mobile operators to utilize free, unlicensed 902-928 MHz spectrum, which is available in most of the Americas. Unlicensed spectrum is an affordable alternative to licensed spectrum – such as what broadcasters use to transmit their signals. Any company or consumer can use unlicensed spectrum simply by following well-known rules.

xMax developed by xG Technology, Inc. is a cognitive radio based mobile VoIP and computer networking system operating in the license-free ISM 900 MHz band (902-928 MHz). xMax is built upon an end-to-end Internet Protocol (IP) system infrastructure that includes a line of base stations, mobile switching centers (MSC), handsets and modems.

A press report was published in 2005 quoting inventor Joseph Bobier. The technology was said to compete with WiMax, but details were initially not disclosed. By 2006, the company announced it had "completed" the technology after six years of development. In 2009, a blogger wrote that he witnessed a xMax mobile VoIP pilot network operated by the company in Fort Lauderdale: "xMax worked well and is real. When you realize that this company may have found a way to take a frequency riddled with wireless garbage and turn it into a fully functioning wireless voice and data network you start to see how much of a game changer this could be for the wireless industry."

From 2007 through 2009 Phil Karn published some analysis of the technology claims.