TowerJazz And UCSD To Launch SiGe 110 GHz Transmitter
Targets for the silicon-germanium based phased array transmitters include automotive, radar, aerospace and defence, passive imaging, security, and millimetre wave imaging
TowerJazz and the University of California, San Diego (UCSD) aim to demonstrate what they say is the first wafer-scale phased array with 16 different antenna elements operating in the 110 GHz frequency range.
The first success of the collaboration was achieved for the RFIC using TowerJazz’s proprietary models, kit and the millimetre wave capabilities of its 0.18 µm SiGe BiCMOS process, SBC18H3.
The SBC18H3 process targets applications for automotive radar, aerospace and defence, passive imaging, security, and millimetre wave imaging. The collaboration of the phased array chip was partly funded by DARPA.
The wafer-scale SiGe BiCMOS chip is 6.5 x 6.0 mm and combines the 110 GHz source, amplifiers, distribution network, phase shifters and high-efficiency on-chip antennas. This should allow a new generation of miniature and low-cost phased arrays for W-band (75 - 110 GHz) applications.
This advancement better serves the needs of the greater than $100 million emerging markets of auto radar and passive imaging (security). The antennas are integrated on-chip which removes the expensive transitions and distribution network between the phased array and the off-chip elements.
This wafer-scale phased array with 16 radiating elements, together with all the necessary CMOS control circuits, is capable of electronic beam scanning to +/-40 degrees in all planes.
The architecture could be scaled to 64 elements (8 x 8) or 256 elements (16 x 16) due to on-chip antenna integration and the single chip integration of multiple elements.
By developing this wafer-scale chip, UCSD has successfully demonstrated independent amplitude and phase control at 106 - 114 GHz for all 16 different antenna elements, and provides commercial availability of highly scalable (from 16 elements to 256 elements) RF-IC transmitters for W-Band and D-Band phased array applications.
The chip was designed and tested by Woorim Shin, Ozgur Inac, and Bonhyun Ku, all from the Electrical and Computer Engineering Department at UCSD under the supervision of Gabriel M. Rebeiz, and was partially sponsored by the DARPA GRATE program under the direction of Carl McCants. The work was done under a subcontract to UCSD from TowerJazz.
The phased array chip was developed using TowerJazz’s SBC18H3 BiCMOS process which offers both high-performance 0.18 µm SiGe bipolar and high quality passive elements combined with high density 0.18 µm CMOS, to enable high-speed networking and millimetre wave applications.
The process offers SiGe transistors with peak Fmax of 280 GHz and peak Ft of 240 GHz, ideal for low-power, high performance millimetre wave circuits, while replacing the need for more expensive GaAs chips.
The SBC18H3 comes standard with 1.8 and 3.3 V CMOS (dual-gate), deep trench isolation, lateral and vertical PNP transistors, MIM capacitors, high performance varactors, poly-silicon as well as metal and N-well resistors, p-i-n and Schottky diodes, high-Q inductors, triple well isolation, and six layers of metal.
“This is yet another advancement in the area of phased arrays that we are proud to announce. We have a track record of successful collaboration with TowerJazz and the ability to bring this innovative design from UCSD to market depends strongly on TowerJazz’s SiGe BiCMOS process which enables lower-cost phased arrays by integrating many functions and high efficiency antennas on the same silicon chip," says Gabriel M. Rebeiz, Professor of Electrical Engineering at UCSD, the lead professor on this chip.
"We believe the results achieved by UCSD’s phased array transmitter demonstrates the remarkable teamwork between TowerJazz, UCSD and DARPA to provide novel capabilities and technologies to both the aerospace and defence community as well as commercial markets," adds David Howard, TowerJazz’s Executive Director and Principal Investigator for DARPA GRATE Program.
“TowerJazz enjoys the long term, very productive working relationship we have with Rebeiz, one of the top RF research professors in the world."