NEWARK, N.J. » A former employee of a New Jersey-based defense contractor was sentenced today to more than five years in prison for taking U.S. military technology trade secrets to his native China.

Sixing Liu, a legal permanent resident who has lived in the U.S. for 19 years, worked for Space & Navigation, a division of New York-based L3 Communications.

He was arrested at his Deerfield, Ill., home in March 2011 and accused of taking restricted military data and presenting them at two conferences in China. Liu was found guilty last fall on six counts of exporting defense data without permission plus separate counts of possessing stolen trade secrets and lying to authorities.

The projects Liu’s company worked on included technology for rocket launchers, mobile howitzers and missiles.

Prosecutors said during trial that Liu took a personal laptop computer to conferences on nanotechnology in Chongqing in 2009 and Shanghai in 2010 and, while there, gave presentations that described the technology he was working on. That violated U.S. laws that prohibit exporting defense materials without a license or approval from the Department of State, prosecutors said.

Thousands of company files were found on his computer when he arrived at Newark Liberty International Airport in 2010, prosecutors said.

The government wanted Liu sentenced to at least eight years in prison, while Liu’s attorney sought a sentence of one year, one day, contending that Liu made an error in judgment but never jeopardized national security.

The lawyer, James Tunick, said his client had not intentionally violated any rules and had downloaded information on his personal laptop to work on outside the office.