Inside Apple?s Antenna Design Lab

After a press conference Friday addressing the iPhone 4’s antenna, Apple gave journalists a private tour of its radio-frequency test facility to provide a glimpse into the process of designing wireless products such as iPhones and iPads.

Led by Ruben Caballero, a senior engineer and antenna expert at Apple, the tour gave about 10 reporters and bloggers a peek at Apple’s custom-built wireless testing lab, which consists of several anechoic chambers to measure frequency of each device in various settings.

The tour was held after a press conference, in which Steve Jobs attempted to mitigate a media thunderstorm surrounding the iPhone 4’s purportedly flawed antenna by offering free cases to customers. During the conference, Jobs reinforced his original position that every phone has reception issues when held in certain ways, and he said a flawed software algorithm was making the iPhone 4’s attenuation look worse than it actually was.

Apple called the lab a “black” lab because it was a secret facility that even some employees were unaware of. The company made the lab’s existence public to show that Apple takes antenna design and wireless testing seriously.

“This is the most advanced lab for doing RF studies that anyone in the world has,” said Phil Schiller, vice president of marketing at Apple. “The designs we do wouldn’t be possible without it.”

Each test chamber is lined with blue pyramid-shaped styrofoam designed to absorb radio-frequency radiation. A robotic arm holding gadgets such as iPads and iPhones spins 360 degrees while a piece of analytics software (ironically running on Windows XP) visualizes the wireless activity of each device. Caballero said each gadget is run through a chamber for at least 24 hours.

In another test process Apple also has people sitting inside test chambers, holding a device for about 30 minutes while software analyzes its wireless performance to evaluate its interactions with the human body.�Synthetic heads, hands and even feet (think Nike +) are used for some of these tests as well.

Apple’s testing lab looks similar to Celecom’s cellphone radiation testing lab that Wired.com visited last year. Manufacturers who create wireless products must gain certification from an independent lab, which verifies that each device meets acceptable radiation standards set by the Federal Communications Commission.

The difference with Apple is it built its own lab for the sake of having full, granular oversight on the design (and redesign) of its products. Prototypes go through several iterations and tests before they’re finalized into Apple products. (Of course, having its own lab also helps Apple better guard its secrets.)

Before the iPhone 4 became an official product, prototypes of the device were tested in chambers for about two years until Apple settled on a design, Caballero said.

“It’s not trivial to design antennas,” said Caballero, reminiscing on the days older antennas had a single frequency.

After “passive” testing of devices inside isolated chambers, eventually Apple engineers drive around a large van containing synthetic hands gripping gadgets, with a laptop in the back running wireless analytics software to determine how the devices perform in real-world settings. Sometimes humans sit in the car seats holding the devices, too. During the tour, Apple showed a van containing a table full of synthetic hands gripping iPhone 4 devices.

“To do the most challenging design in the world, this is what we have to do,” said Bob Mansfield, Apple’s senior vice president of Macintosh hardware. “This is hardcore stuff.”

Apple earlier today also posted a description and video of its test lab.

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