Cupertino, Calif. ? The case of a Chinese businessman charged with illegally shipping missile guidance technology to China’s military has intensified concerns about foreign espionage in Silicon Valley.

Qing Chang Jiang, who was to be arraigned today, is at least the fourth Chinese native indicted since October on charges involving the shipment of equipment or trade secrets to China from the nerve center of the U.S. technology industry.

In the three years since the Justice Department established a computer hacking and intellectual property unit in Northern California, there has been a “significant increase” in the number of illegal technology shipments being reported, according to Ross Nadel, the prosecutor who leads the unit.

But, Nadel added, the increase may stem from companies being more willing to report such crimes.

Jiang, 51, was arrested Jan. 10 for allegedly shipping three microwave amplifiers that could be used to improve the quality of long-distance calls — or to make intercontinental ballistic missiles more accurate.

Prosecutors say Jiang, a Chinese citizen, shipped the amplifiers without a license to a company in Shijianzhuang, China, that shares its address with the 54th Research Institute, a Chinese military agency. Prosecutors allege Jiang shipped the amplifiers for use by the Chinese military.

Most exports to the military agency are outlawed. The U.S. government says the agency poses an “unacceptable risk of diversion to developing weapons of mass destruction.”

His lawyer, Lupe Martinez, denied that Jiang was part of any organized Chinese effort to get U.S. technology and questioned whether corporate giants that legally export billions of dollars in equipment to China were held to the same standard.

Al Santoli, a China expert with the nonpartisan think tank American Foreign Policy Council, said Chinese citizens in Silicon Valley frequently shipped technology through intermediaries to the People’s Liberation Army.

“They have hundreds of people and little companies operating like this,” Santoli said.