Pharrowtech Shows 60GHz Active Phased Array

Article By : Nitin Dahad, EE Times

Imec spinoff aims to increase range and field of telecom backhaul nodes

LONDON — A spinoff initiative currently incubating at research institute Imec this week demonstrated a 60-GHz active phased array prototype to telecoms operators and OEMs at the Telecom Infra Project Summit here.

Pharrowtech, co-founded by four researchers at Imec, says that its solution paves the way for telecom OEMs to dramatically increase range and field of view of backhaul nodes, access points and home units. It is built using low-cost, high-volume chip and antenna technology, paving the way for accelerated deployment of cost-effective high-speed internet in rural, urban, and suburban environments, according to the company. 

Imec has been pioneering low-cost millimeter-wave systems since 2005, according to Wim Van Thillo, one of the Pharrowtech co-founders and a program director at Imec. He said Pharrowtech’s modular design offers operators the flexibility to deploy in different neighborhood types with diverse building and vegetation densities while still meeting all regulatory requirements.

Pharrowtech’s prototype has a logn long range and large field of view, achieved through 256 antenna elements driven by 128 power amplifiers, Van Thillo told EE Times. Its proprietary chips are realized in high-volume CMOS to ensure low cost and power consumption, he said.

“We believe we are the first ones to demonstrate such a large 60-GHz active array at this cost/power point, optimized for 60-GHz fixed wireless access,” Van Thillo said. “With our technology, operators will meet the combination of range, field of view, and robustness (weather, foliage) that will be required for a viable deployment of 60-GHz FWA.”

Van Thillo said Pharrowtech has fully functional lab prototypes that it will turn into carrier-grade engineering samples in the coming year. The startup plans to supply engineering samples to Deutsche Telekom and a major OEM that Van Thillo declined to name in the first quarter of 2020, he said, with volume ramp up planned for the second half of 2020.

Pharrowtech’s intellectual property is based on a prototype transceiver outlined by Imec in April 2017. At that time, the 60-GHz transceiver chip compatible with WiGig consisted of a phased-array transceiver IC and a small four-antenna module. The transceiver IC was implemented in 28-nm CMOS technology and measured 7.9 mm2. It enables beamforming for directional transmission or reception, direct down-conversion, and beam steering (phase shifting) in the analog baseband.

By scaling up the number of antennas, the range of the 60-GHz radio can be increased to a few hundred meters, making the technology attractive for 5G small-cell backhaul applications and fixed wireless access (FWA). With FWA and small-cell backhaul, multigigabit-per-second connections can be brought to the home without the need for fiber in the last kilometer. For FWA, the base station can be put on a streetlamp or a rooftop, while the radio link toward the end user is preferably located outdoors for minimal signal loss. Millimeter-wave FWA can be combined with millimeter-wave backhaul to wirelessly carry the data traffic deeper into the communication network — toward the mobile network operator’s core network.

Van Thillo said that while the IP is based on this, significant improvements have been made since then. “We will support all essential IEEE 802.11ay features in the radio,” he said. He added that the company is in the process of seeking funding but did not disclose how much.