Some phased arrays are larger than highway billboards and the most powerful – used as sophisticated radar, surveillance and communications systems for military aircraft and ships – can cost hundreds of millions of dollars. The high cost has prevented significant spread beyond military and high-end satellite communication applications. Engineers are now working to miniaturize them and fully integrate them into silicon-based electronic systems for both military and commercial applications.
The new UCSD chip packs 16 channels into a 3.2 by 2.6 mm² chip. The input signal is divided on-chip into 16 different paths with equal amplitude and phase using an innovative design, and the phase and gain of each of the 16 channels is controlled electronically to direct the antenna pattern (beam) into a specific direction.
By manipulating the phase, you can steer the beam electronically in nanoseconds. With the amplitude, you control the width of the beam, which is critical, for example, when you send information to from one satellite to another but you don’t want the signal to reach any nearby satellites. And with amplitude and phase control, you can synthesize deep nulls in the antenna pattern so as to greatly reduce the effect of interfering signals from neighboring transmitters.
If you take the same design and move it to the 24 or 60 GHz range, you can use it for commercial terrestrial communications,” said Rebeiz who is also a lead on a separate project, funded by Intel and a UC-Discovery Grant, to create silicon CMOS phased array chips that could be embedded into laptops and serve as high speed data transfer tools.
“If you wanted to download a large movie file, a base station could find you, zoom onto you, and direct a beam to your receiver chip. This could enable data transfer of hundreds of gigabytes of information very quickly, and without connecting a cable or adhering to the alignment requirements of wireless optical data transfer,” explained Rebeiz who estimated that this kind of system could be available in as little as three years.