TowerJazz, the global specialty foundry leader, and The University of California, San Diego (UCSD), provider of a leading program in microwave, millimeter-wave and mixed-signal RFICs, today announced they have collaborated to demonstrate the first wafer-scale phased array with 16 different antenna elements operating at 110 GHz frequency range. First time success was achieved for the RFIC using TowerJazz’s own proprietary models, kit and the mmWave capabilities of its 0.18-micron SiGe BiCMOS process, SBC18H3. The device targets applications for automotive radar, aerospace and defense, passive imaging, security, and mmWave imaging. The collaboration of the phased array chip was partly funded by DARPA.
The wafer-scale SiGe BiCMOS chip is 6.5×6.0mm and combines the 110 GHz source, amplifiers, distribution network, phase shifters and high-efficiency on-chip antennas, allowing a new generation of miniature and low-cost phased arrays for W-band (75-110 GHz) applications. Such an advancement better serves the needs of the greater than $100M emerging markets of auto radar and passive imaging (security). The antennas are integrated on-chip which removes the expensive and lossy 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 (8×8) or 256 elements (16×16) 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.
Phased arrays allow the electronic steering of an antenna beam in any direction and with high antenna gain by controlling the phase at each antenna element. The radiation beam can be “moved in space” using entirely electronic means through control of the phase and amplitude at each antenna element used to generate the beam. This beam steering technique is much more compact and much faster than mechanically steered arrays. Furthermore, phased arrays allow the creation of deep nulls in the radiation pattern to mitigate strong interference signals from several different directions. They have been in use since the 1950’s in defense applications and have seen limited use in commercial system due to their relatively high cost. UCSD’s design and utilization of TowerJazz existing wafer processes are targeted to greatly reduce the cost of phased arrays especially at millimeter-wave frequencies.