Carl L. Dohrman

Microwave Photonics Programs at DARPA

Over the past ten years, DARPA has made significant investments toward advancing the field of microwave photonics. This paper reviews DARPA-funded progress in this subject over the past decade. DARPA-funded research has advanced the state-of-the-art for microwave-photonic components, including low noise laser diodes, electrooptic modulators and high power photodiodes, as well as microwave photonic link configurations, including photonic downconversion, reconfigurable optical filters and optical phase-locked loops. These investments have yielded dramatic improvements in spurious-free dynamic range (SFDR). Measured performance includes SFDRs exceeding 115 dB · Hz2/3 at 16 GHz using broadband externally modulated links; exceeding 120 dB · Hz2/3 at 10 GHz using sub-octave electrooptic modulators; near 135 dB · Hz2/3 at 100 MHz using optical phased-locked loops as linear phase demodulators; and exceeding 125 dB · Hz 2/3 at 5 GHz using optical filtering, downconversion and predistortion compensation.

The DARPA COSMOS program: The convergence of InP and Silicon CMOS technologies for high-performance mixed-signal

The COmpound Semiconductor Materials On Silicon (COSMOS) program of the U.S. Defense Advanced Research Projects Agency (DARPA) focuses on developing transistor-scale heterogeneous integration processes to intimately combine advanced compound semiconductor (CS) devices with high-density silicon circuits. The technical approaches being explored in this program include high-density micro assembly, monolithic epitaxial growth, and epitaxial layer printing processes. In Phase I of the program, performers successfully demonstrated world-record differential amplifiers through heterogeneous integration of InP HBTs with commercially fabricated CMOS circuits. In the current Phase II, complex wideband, large dynamic range, high-speed digital-to-analog convertors (DACs) are under development based on the above heterogeneous integration approaches. These DAC designs will utilize InP HBTs in the critical high-speed, high-voltage swing circuit blocks and will employ sophisticated in situ digital correction techniques enabled by CMOS transistors. This paper will also discuss the Phase III program plan as well as future directions for heterogeneous integration technology that will benefit mixed signal circuit applications.

The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program: Convergence of compound semiconductor devices and silicon-enabled architectures

The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is developing transistor-scale heterogeneous integration processes to intimately combine advanced compound semiconductor (CS) devices, as well as other emerging materials and devices, with high-density silicon CMOS technology. This technology is currently enabling RF/mixed signal circuits with revolutionary performance. For example, InP HBT + CMOS technology is being utilized in advanced DACs and ADCs with CMOS-enabled calibration and self-healing techniques for correcting static and dynamic errors in situ. Such CMOS-enabled self-healing techniques are expected to more generally enable improved CS-based circuit performance and yield in the presence of process and environmental variability, as well as aging. DAHI is also expected to enable the integration of high power CS devices with silicon-based linearization techniques to realize highly power efficient transmitters. By enabling this heterogeneous integration capability, DAHI seeks to establish a new paradigm for microsystems designers to utilize a diverse array of materials and device technologies on a common silicon-based platform.

Materials and Integration Strategies for Modern RF Integrated Circuits

The DARPA Microsystems Technology Office is developing revolutionary materials, devices, and integration techniques for meeting the RF integrated circuit performance requirements for advanced modern RF systems. DARPA is enabling these systems through systematic development of materials and devices, circuits, and integration technologies for compound semiconductors. The DARPA Nitride Electronic Next-Generation Technology (NEXT) program is developing high performance nitride transistors for high-speed RF, analog and mixed signal electronics, thus overcoming the Johnson figure of merit limits to achieving simultaneous high-speed operation and high breakdown voltage. The DARPA Microscale Power Conversion (MPC) program is developing nitride-based technology to enable dynamic envelope-tracking power conversion embedded in RF radiating elements. The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is developing transistor-scale heterogeneous integration processes to intimately combine advanced compound semiconductor (CS) devices, as well as other emerging materials and devices, with high-density silicon CMOS technology. Taken together, these programs are addressing many of the critical challenges for next-generation RF modules and seek to revolutionize DoD capabilities in this area.

Microwave photonics: Recent programs at DARPA

Microwave photonic components and systems are of significant interest to radar and communications systems used on military platforms. This paper highlights recent experimental results and system architectures aimed at moving microwave photonic component developments to system demonstrations and transitions to deployed military systems.

The DARPA COSMOS and ELASTx Programs: Towards Next Generation Linearized Microwave/Mm-Wave Transmitters

The COmpound Semiconductor Materials On Silicon (COSMOS) program of the U.S. Defense Advanced Research Projects Agency (DARPA) focuses on developing transistor-scale heterogeneous integration processes to intimately combine advanced compound semiconductor (CS) devices with high-density silicon circuits. The technical approaches being explored in this program include high-density micro assembly, monolithic epitaxial growth, and epitaxial layer printing processes. Through heterogeneous integration of advanced InP HBTs with commercially fabricated CMOS circuits, the program has successfully demonstrated world-record differential amplifiers and is currently developing complex wideband, large dynamic range, high-speed digital-to-analog converters (DACs) employing sophisticated in situ digital correction techniques enabled by CMOS integration. This paper will also discuss future directions of technical approaches, for example integration of high power CS devices such as GaN transistors with silicon-based linearization techniques developed under DARPAs Efficient Linearized All-Silicon Transmitter ICs (ELASTx) program to realize next-generation microwave/mm-wave transmitters. In these future transmitters, the high breakdown voltage CS devices will be used to implement efficient, although non-linear, power amplifiers while the required linearity for complex waveforms will be recovered through integrated linearization architectures.

A Review of Electronic-Photonic Heterogeneous Integration at DARPA

The Defense Advanced Research Projects Agency (DARPA) has developed programs in integrated photonics for over a decade. From the Electronic-photonic Integrated Circuits (EPIC) program to the more recent Electronic-photonic Heterogeneous Integration (E-PHI) program, DARPA programs have established a library of high-performance silicon photonic devices and have demonstrated heterogeneous integration processes. These components and integration techniques, combined with automated design software tools, form the basis of the new American Institute for Manufacturing Integrated Photonics which will establish a photonics manufacturing ecosystem in the United States through a combination of public and private funds.

A Revolution on the Horizon from DARPA: Heterogeneous Integration for Revolutionary Microwave\/Millimeter-Wave Circuits at DARPA: Progress and Future Directions

The Microsystems Technology Office of the U.S. Defense Advanced Research Projects Agency (DARPA) is developing revolutionary materials, devices, and integration techniques to meet the performance requirements for advanced microwave and millimeter-wave (mmW) systems. The DARPA Compound Semiconductor Materials on Silicon (COSMOS) program focused on developing new methods to tightly integrate compound semiconductor (CS) technologies within state-of-the-art silicon (Si) complementary?metal-oxide-semiconductor (CMOS) circuits to achieve unprecedented circuit performance levels. The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is continuing that work by developing heterogeneous integration processes to intimately combine advanced CS devices, as well as other emerging materials and devices, with high-density Si CMOS technology. DARPA has also pushed limits in Si technology and driven seminal developments in gallium nitride (GaN) device technology. Taken together, these programs are addressing many critical challenges for next-generation microwave and mmW systems and seek to revolutionize U.S. Department of Defense (DoD) capabilities in these areas.

Path to 3D heterogeneous integration

The DARPA Microsystems Technology Office is developing revolutionary materials, devices, and integration techniques for meeting the performance requirements for advanced microwave and RF systems. The DARPA Compound Semiconductor Materials on Silicon (COSMOS) program focused on the development of new methods to tightly integrate compound semiconductor (CS) technologies within state-of-the-art silicon CMOS circuits in order to achieve unprecedented circuit performance levels. The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is continuing that work by developing heterogeneous integration processes to intimately combine advanced CS devices, as well as other emerging materials and devices, with high-density silicon CMOS technology. Taken together, these programs are addressing many of the critical challenges for next-generation RF modules and seek to revolutionize DoD capabilities in this area.

Heterogeneous BiCMOS technologies and circuits and the DARPA Diverse Accessible Heterogeneous Integration (DAHI) program

The DARPA Diverse Accessible Heterogeneous Integration (DAHI) program is developing transistor-scale heterogeneous integration processes to intimately combine advanced compound semiconductor (CS) devices, as well as other emerging materials and devices, with high-density silicon CMOS technology. This technology is currently enabling BiCMOS RF/mixed signal circuits with revolutionary performance. For example, InP HBT + CMOS technology is being utilized in advanced DACs and ADCs with CMOS-enabled calibration and self-healing techniques for correcting static and dynamic errors in situ. Such CMOS-enabled self-healing techniques will more generally enable improved CS-based circuit performance and yield in the presence of process and environmental variability, as well as aging. DAHI is also expected to enable the integration of high power CS devices with silicon-based linearization techniques to realize highly power efficient transmitters. By enabling this heterogeneous integration capability, DAHI seeks to establish a new paradigm for microsystems designers to utilize a diverse array of materials and device technologies on a common silicon-based platform.