Pivotal2
(Image courtesy of Pivotal Commware).

Start-Up Makes Case for Software-Defined Antennas Using Metamaterials

Pivotal Commware, a start-up based in Bellevue, Wash., claims to have cracked the code to affordable phased array antennas that beam communications signals directly into devices, instead of blanketing radio waves over broad areas.

The company’s antennas rely on metamaterials instead of costly components that have confined the technology to the defense and aerospace sectors for decades. The antennas act like a platform for what Pivotal calls holographic beamforming, which acts like a traffic signaling system for radio waves to increase the throughput of 4G and 5G networks.

“In that sense, it is a software-defined antenna,” said Eric Black, Pivotal’s chief technical officer and a former Boeing scientist, in a recent phone interview. “Because you can shape the radio pattern of the antenna using software, you don’t need to physically go out and reconfigure the antenna.”

Pivotal, which was founded in 2016 and raised $17 million last month from investors including Bill Gates, is the fourth metamaterials spinoff from investment firm Intellectual Ventures. Founded by former Microsoft chief technology officer Nathan Myhrvold, the firm has stockpiled over 200 patents for metamaterials, which bend light, sound, and radio waves in unnatural ways.

The concept of phased array beamforming is a century old. But traditional phased arrays need bulky and expensive phase shifters to dynamically control antenna beams. MIMO systems, in which two or more transmitter and receivers coordinate to beam signals into multiple devices, require digital signal processors (DSPs) that consume lots of power.

Pivotal’s antennas are more streamlined. “Instead of phase shifters or DSP radios, we use this very simple switched control antenna element, which could be as simple as a varactor or field-effect transistors,” Black said. “Our cost is lower, size is thinner, weight is lower, and power consumption is lower.”

Pivotal’s metamaterial antennas consist of a printed circuit board covered in metal cells smaller than the wavelength of the radio waves being manipulated. The control software activates antenna elements to scatter radio waves into beams with all the normal characteristics of a radiating aperture, which allows the same spectrum band to be reused by multiple beams simultaneously.

The software changes the properties of the antenna by pointing out where to apply DC biases, which can switch control elements within a microsecond. The antennas suppress side-lobes that could cause interference, improving spectral efficiency or how much data can be transmitted to a certain number of smartphones or other devices.

(Image courtesy of Pivotal Commware).

With holographic beamforming, signals can travel further with higher gain. That would be particularly useful to prevent millimeter waves to be used in 5G networks from being blocked by buildings and from fading over just a few kilometers. Black said that the company had prototype antennas that span 500 megahertz to 60 gigahertz.

Pivotal’s value proposition is that its beamforming antennas boost throughput for cellular networks and provide a cheaper way to haul information between base stations instead of using fiber optic cable. The antennas could also reduce base stations along shores for connecting ships, along tracks for trains, and across the country for airplanes and drones.

“We think that travel – whether by plane, train or ship — shouldn’t be a broadband dead zone,” said Brian Deutsch, Pivotal’s chief executive, after the company announced its funding round last month. “In this market, broadband connectivity worthy of the name means continuous tracking by high gain beams with electronic-speed beam switching.”

Pivotal has already turned heads. For the last year, it has been reaping revenue from a contract with an in-flight wireless provider for airplanes. “End of last year, I’m sitting down with accountants trying to figure out whether this pre-Series A start-up is going to have to pay taxes or not,” Deutsch said in an interview. He declined to identify the customer.

Pivotal is not alone is trying to spruce up electronically-scanning arrays. Torrance, Calif.-based Thinkom supplies the phased array antennas used for Gogo’s in-flight communications system, but its platform mechanically rotates a series of internal resonating plates to assist in directing radio beams. Pivotal’s are completely electronic and can conform to curved surfaces.

With the $17 million in funding, Pivotal plans to aggressively grow its 20-person workforce and expand the facilities where it does development work. The company is also looking to hire software programmers to help make it easier for wireless companies to add holographic beamforming to current cellular networks, Black said.

Other Intellectual Ventures spinoffs include Kymeta, which has raised $217 million in funding over the last five years to develop metamaterial antennas for satellite communications. The other two are Echodyne and Evolv Technology, which sell radar vision systems and airport security scanners, respectively. Together, they have raised $73 million.

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