UCSD And Jazz Semiconductor Develop 8-Element 6 To 18 Ghz Phased Array Chip

San Diego and Newport Beach, CA - The University of California, San Diego (UCSD), provider of a program in microwave and millimeter-wave RFICs and mixed-signal, and Jazz Semiconductor, a wholly owned subsidiary of Jazz Technologies, Inc. and an independent wafer foundry focused primarily on specialty CMOS process technologies, recently announced that they have collaborated to develop an 8-element RFIC phased array receiver covering the 6-18 GHz frequency range. First time success was achieved for the RFIC chip using Jazz Semiconductor's own proprietary models, kit and 0.18-micron silicon germanium (SiGe) BiCMOS process (SBC18HX). The SiGe BiCMOS chip is only 2.2x2.3 mm, replaces at least 16 GaAs chips, consumes 20x less power than traditional phased array implementations, and will allow a new generation of miniature and very low-cost phased arrays for X to Ku-Band applications. This is the first demonstration, ever, of a single silicon chip with 8 complicated 6-18 GHz phased array receivers together with all the necessary CMOS controlling circuits.

By developing this chip, UCSD has successfully demonstrated independent amplitude and phase control at 6-18 GHz of 8 different antenna elements with at least 4-bit of phase resolution, and provides commercial availability of highly integrated RFIC modules for X and Ku-Band phased array applications. The chip was designed and tested by Kwangjin Koh, a graduate student from the Electrical and Computer Engineering School at UCSD, and was sponsored by the DARPA SMART (Scalable Millimeter-Wave Array Technology) program under the direction of Dr. Mark Rosker, and under a subcontract to UCSD from Teledyne Scientific Corporation in Thousand Oaks, CA.

The RFIC chip contains 8 silicon low-noise amplifiers operating at 6-18 GHz, 8 phase shifters with at least 4-bit of phase control, and an 8:1 active power combiner with very wide bandwidth, together with all the digital functions needed to control the chip such as the address decoders for the individual 8-elements, the memory latches for the phase settings, the clock enable functions to load the information on the chip, and power regulators. The chip is only 2.2x2.3 mm in area, consumes 140-200 mA of DC current from a 3.3 V power supply, provides an RF gain from 12 to 24 dB with a noise figure of 6 dB, and can be integrated directly with 8 planar antennas on a standard printed circuit board.

Furthermore, the chip can operate over a narrow bandwidth for communication systems, or over an instantaneous 12 GHz (6-18 GHz) bandwidth while keeping all its performance un-changed, thus solving one of the key barriers to complex phased array fabrication while still leveraging the standard low cost RF packaging techniques. The application areas are in low cost phased arrays for mobile satellite systems, smart-antenna wireless systems for high data-rate communications, and of course, defense systems such as radars and high-bandwidth telecommunication links covering the X to Ku-Band frequency range.

The phased array chip was developed using Jazz Semiconductor's SiGe BiCMOS process, SBC18HX, which offers high-performance 0.18-micron SiGe bipolar and high quality passive elements combined with high density 0.18-micron CMOS for high-speed networking and millimeter wave applications. The process offers SiGe transistors with peak Ft of 155GHz and peak Fmax of 200GHz ideal for low-power, high performance millimeter wave and OC-192 and OC-768 circuits. SBC18HX comes standard with three bipolar (NPN) transistor types, 1.8 and 3.3 volt 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, high-Q inductors, a triple well option, and six layers of metal.

"UCSD believes that the silicon RFIC phased array controller will be a disruptive element in the design of future phased array systems and will enable low-cost phased arrays in the near future by integrating so many functions on the same silicon chip," said Gabriel M. Rebeiz, Professor of Electrical Engineering at UCSD, a co-developer of this chip. "Our success in bringing this exciting technology to market depends strongly on the Jazz 0.18-micron SiGe BiCMOS process which enables integration of both the RF functions and the digital blocks all on the same chip. We were delighted to work with Jazz, whom we view as one of the leading foundries in the RF semiconductor space."

"We believe the results achieved by UCSD's RFIC phased array controller demonstrate the still-to-be-tapped capability of the highly advanced wafer processes, models and kits offered to customers by Jazz. We are pleased to be a part of the expansion of this technology, and others, to commercial markets," said David Howard, executive director of new product technology for Jazz Semiconductor. "UCSD and Teledyne Scientific's use of the Jazz multi-project wafer (MPW) program provided a low cost approach to enable an innovative, cost-effective silicon-based chip, designed to address the high data-rate communications and satellite-based systems markets."

Phased Arrays

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 1950s in defense applications and have seen limited use in commercial system due to their relatively high cost. UCSD's design and utilization of Jazz existing wafer processes are targeted to greatly reduce the cost of phased arrays.

SOURCE: The University of California, San Diego (UCSD) and Jazz Technologies, Inc.