Navy electronics researchers push for new RF solid-state breakthroughs

By Edward J. Walsh

WASHINGTON — U.S. military researchers want to figure out new ways to fabricate advanced solid-state devices called wideband gap semiconductors, which experts say are necessary to design low-noise power amplifiers for future military radio-frequency (RF) systems.

Such a program, which would be a cooperative effort of the Office of Naval Research (ONR) in Washington and the Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., would seek to develop cost-effective and reliable manufacturing processes for fabricating wideband gap semiconductors.

ONR experts say the program could resemble the U.S. Department of Defense Microwave/Millimeter Wave Monolithic Integrated Circuit program — better known as MIMIC — carried out from 1990 through 1995 to develop mature gallium arsenide solid-state devices

A new breed of power amplifiers using wideband gap semiconductor technology could combine with other breakthroughs in fast transistors to provide order-of-magnitude performance advances for communications, sensor, electronic warfare, and other high-performance RF systems for all the services, ONR researchers say.

The Naval Research Laboratory's Electronics Science & Technology division also is working on wideband gap semiconductors, based on gallium nitride, which NRL officials say support higher frequencies than silicon carbide.

Yet Navy solid-state research does not end with wideband gap semiconductors. ONR also is sponsoring research into transistors that support analog-to-digital converters and direct-digital synthesizers to generate signals that are free of background noise.

This research, at HRL Laboratories in Malibu, Calif., and TRW in Redondo Beach, Calif., could lead to transistors necessary for high-performance beam formers, filters, modulators, and low-noise oscillators that further refine RF signals for military systems, ONR experts say.

The Boeing Co., General Motors, and Raytheon Co jointly and equally own HRL Laboratories, formerly known as the Hughes Research Laboratories.

The HRL/TRW effort will lead to wider insertion of solid-state devices in RF systems, ONR officials say. They point out that new radars of all the services have been designed as solid-state systems. These include the Navy's multi-function radar and volume-search radar; and the high-power discriminator under development by Raytheon for future surface ships; the Army's theater high-altitude area defense system radar; and the Air Force's F-22 jet fighter radar.

In a separate but related effort, the ONR is funding a two-phase program called the advanced multi-function RF concept (AMRFC) that aims at developing devices to help integrate several different RF beams for future ships and aircraft. In this way, platform designers could eliminate electromagnetic interference and lower platform signatures by reducing the number of antenna apertures on board.

Lockheed Martin Naval Electronics & Surveillance Systems in Baltimore, Northrop Grumman's Electronic Sensor Systems Sector in Baltimore, and Raytheon Naval & Maritime Integrated Systems in Portsmouth, R.I., are participating in the phase 1 AMRFC work.

Need for vacuum electronics
The Army, however, following evaluation of competing solid-state and vacuum-based designs has selected a vacuum-electronics technology architecture for its new TYQ-47 Firefinder radar.

ONR officials point out that the transmitters of currently fielded RF systems use power amplifiers based on vacuum electronics technology such as traveling wave tubes. Yet receiver functions in these field systems are nearly all low-noise systems based on solid-state technology.

The services will continue to require solid-state and vacuum technology, insist Bobby Junker, head of the Information, Electronics, and Surveillance Department at ONR, and Gerald Borsuk superintendent of NRL's Electronics Science & Technology division, which oversees the Navy's vacuum electronics program. They say that systems designers must make decisions on the architectures of new military RF systems on considerations of cost, risk, and performance requirements.

Junker says that cost and performance tradeoffs always will be necessary to determine whether systems should adopt solid-state or vacuum electronics device technology. He adds though that ONR experts are working to "enable solid-state technology to reach a point where it is affordable" for RF components.

Both ONR and NRL officials emphasize that advanced solid-state and vacuum-electronics work aims at meeting the highly demanding performance requirements for the "front end" signal processing for military-unique RF systems.

They point out that commercial off-the-shelf (COTS) digital devices that are suitable for data-processing, analysis, and other information technology (IT) applications simply cannot meet front-end sensor requirements.

Junker says experts must distinguish between the services' needs for sensor technology on the one hand, and the computing technology under development by commercial companies on the other.

Many government and industry officials, Junker says, assume that commercial investments in electronics can meet service needs can be met by commercial investments in electronics. Furthermore, these officials often do not understand the need for investing in specialized high-performance devices for military applications.

"COTS data-processing devices are primarily available in frequencies under 1 gigahertz (GHz)," he says. "There's nothing available in COTS for RF signal processing for microwave and millimeter-wave applications. Commercial producers aren't addressing the military signal-processing requirements."

ONR has funded several different collaborative efforts with companies and university laboratories that aim at increasing the performance of solid-state devices. In the mid-1990s ONR established a program at the University of California-Santa Barbara (UCSB) to increase the switching speed of new transistors — referred to as heterojunction bipolar transistors (HBTs) — by reducing the capacitance caused by the semiconductor metal used in fabricating the device.

In 1995 UCSB scientists achieved a critical breakthrough when a researcher mistakenly left a device in an etching machine longer than planned. The process removed a portion of the semiconductor material on the device, which resulted in a dramatic increase in switching speed. In 1999 the program achieved a speed of 1,200 GHz, or 1.2 Terahertz (THz), and now is expected to reach 2 THz.

Silicon transistors will achieve a speed of 100 GHz in 2006, Junker points out, citing a study at the Semiconductor Industry Association in San Jose, Calif. Currently, he says, silicon-based direct-digital synthesizers are available commercially at speeds in the range of 300 MHz. DARPA, in a program now completed, achieved a speed of 900 MHz using gallium arsenide — the primary device material used in the MIMIC program.

The ONR-funded work has demonstrated a logic speed for HBTs of 82 GHz, says Max Yoder, director of the ONR's Electronics Division. The highest logic speed achievable with silicon is 1.4 GHz.

Junker stresses that the HBT program aims at developing a high-power, low-noise transistor for front-end signal processing components.

These components could include analog-to-digital converters — direct-digital synthesizers — that generate signals, as well as beam-formers, oscillators, modulators, and filters, for new military sensor, communications, and electronic warfare systems. He stresses, though, that military systems designers require such highly specialized devices in limited numbers.

The services will continue to require vacuum-electronics-based amplifiers for some time, because advanced devices such as the wideband-gap semiconductors required for low-noise amplifiers are not yet economically available, ONR officials say.

The cost advantage of vacuum devices is "hard to beat," Yoder says — particularly for applications such as mechanical steering of a single RF beam. Vacuum technology will continue to cost less than solid-state, he says, for the foreseeable future.

Junker says though that in terms of performance, solid-state devices will be superior to vacuum, even for single-beam applications. High-power vacuum-based amplifiers, Yoder adds, have been required for some transmitter applications because of inadequate receiver performance. He says that the introduction of more sensitive solid-state receivers that reduce noise levels while maintaining required operating capabilities, will permit reduced levels of transmit power. This, he says, will eliminate the need for the high-power vacuum-based amplifiers.

For future transmitter architectures, moreover, wideband gap amplifier modules fabricated with gallium nitride will result in lower costs because the system will require fewer modules. These modules are capable of generating eight to 10 times the power of gallium arsenide-based modules.

The systems approach for decisions on either solid-state or vacuum should be based on a development of a "programmable system," according to Junker. Although vacuum electronics devices generate more power then transistors, the key factor is overall system power and performance, not individual device power.

He says that while solid-state is not currently affordable for single functions, it will provide extremely high performance levels for all front-end components. The future solid-state architecture, consisting of the wideband gap and HBT technologies, will support not only communications, electronic warfare, and radar, but also guidance, target-illumination systems, and other RF systems.

In the commercial arena, ONR officials say also that commercial manufacturers of cellular telephones expect in coming years to introduce the capability to transmit as many as 100 separate signals on single beams.

Yoder says that such a capability, referred to as code-division multiple access or wideband code multiple access, requires high-power amplifiers based on solid-state wideband gap semiconductor technology to manage the highly linear discrimination among signals and avoid problems of cross-modulation. No wireless company, he says, is considering vacuum electronics for such applications.

The ONR-DARPA collaborative program under discussion will focus initially on cost-effective ways of producing new materials — primarily gallium nitride — for use in the wide-band gap semiconductors. Early development wideband gap devices built from gallium nitride have generated six watts per millimeter (total power per transistor) compared to 0.8 watt for gallium arsenide a large-area devices.

The program would build on work already underway through the ONR-led AMRFC phase 1 effort. The three AMRFC phase-1 participants — Lockheed Martin, Northrop Grumman, and Raytheon — now are developing gallium arsenide devices that would be used to integrate communications and electronic warfare functions.

The companies currently are working toward a phase 1 demonstration scheduled for late 2003. Phase 2 aims at using new wideband-gap semiconductors to build direct digital synthesizers, and would incorporate radar capabilities.

Get All the Military Aerospace Electronics News Delivered to Your Inbox or Your Mailbox

Subscribe to Military Aerospace Electronics Magazine or email newsletter today at no cost and receive the latest information on:

  • C4ISR
  • Cyber Security
  • Embedded Computing
  • Unmanned Vehicles

Get All the Military Aerospace Electronics News Delivered to Your Inbox or Your Mailbox

Subscribe to Military Aerospace Electronics Magazine or email newsletter today at no cost and receive the latest information on:

  • C4ISR
  • Cyber Security
  • Embedded Computing
  • Unmanned Vehicles

Military & Aerospace Photos

Most Popular Articles

Related Products

XPedite7574 | 5th Generation Intel® Core™ i7 Broadwell-H Processor-Based Conduction- or Air-Cooled 3U VPX-REDI Module

The XPedite7574 is a high-performance, 3U VPX-REDI, single board computer based on the 5th genera...

XCalibur1645 | Freescale Eight-Core P4080 Processor-Based Conduction-Cooled 6U VPX Module

The XCalibur1645 is a high-performance, 6U VPX, single board computer supporting Freescale QorIQ ...

XCalibur5090 | Dual Virtex-7 Based Digital Signal Processing 6U LRM FPGA with Quad 2500 MSPS DAC and 3200 MSPS ADC

The XCalibur5090 is a high-performance, reconfigurable, conduction-cooled 6U LRM module based on ...

ScanFaker DRSii - Networked Radar Simulator

High resolution radar stimulator supporting analog and LAN output. Resolution down to 1m is possi...

4G LTE Cellular Omni Concealment Antenna

The 4G LTE Cellular Omni Concealment Antenna from Southwest Antennas measures only 4.70" x 1.70" ...

Body Worn Antennas

Body Worn Antennas from SWA are ideal for covert surveillance applications where the radio and an...

Ultra-Flex Omni Antennas

The Southwest Antennas Ultra-Flex is a line of S-Band & C-Band omni antennas with a unique enviro...

S & C Dual-Band Omni Antennas

SWA Dual-Band Omni Antennas are designed to cover the S & C bands, and are available with multipl...

PowerDNA-PPC5 Cube

5-layer, 100Base-T I/O, Data Acquisition and Control Cube with PowerPC CPU and SD slot. Has slots...


Dual Channel MIL-STD-1553 interface board for Cube I/O chassis with 2 independent, dual redundant...

Related Companies


Is a mechanical engineering consulting company headquartered in Los Angeles, CA with operations in Billerica, MA, pro...

Curtiss-Wright Defense Solutions

About Curtiss-Wright Defense Solutions Curtiss-Wright Defense Solutions (CWDS) is a long established techno...

Dspnor AS

Offers radar signal processing and distribution. The products interface to virtually any radar system in use today. T...


Pelorus Naval Systems is a specialist naval defense engineering and support services company with headquarters in Ran...


PALMARII Dynamics is a Swedish company incorporated in 2012 as a competence centre for specialist naval architecture ...

Southwest Antennas

Southwest Antennas designs and manufactures high-performance RF & Microwave antennas and accessories designed for tod...

CORWIL Technology Corp

CORWIL Technology, the premier US based, IC assembly and test services subcontractor, offering full back-end assembly...

United Electronic Industries Inc

UEI is a leader in the PC/Ethernet data acquisition and control, Data Logger/Recorder and Programmable Automation Con...


IndustryARC primarily focuses on Cutting Edge Technologies and Newer Applications of the Market. Our Custom Research ...

RPMC Lasers Inc

Offers 1500 DPSS lasers, lamp lasers, fiber lasers and diode lasers. Provides, ultrafast, picosecond, nanosecond, cw ...


Harsh Environment Protection for Advanced Electronics and Components

This webinar will offer an opportunity to learn more about ultra-thin Parylene conformal coatings – how they are applied, applications they protect today, and the properties and benefits they offer, includin...

New Design Tools That Help You Develop Radar That Sees the Un-seeable and Detects the Undetectable

Xilinx EW/ISR System Architect, Luke Miller, has new tricks and he’s going to tell you all about them in a new Xilinx Webinar—for free. His Webinar will cover new ways to implement Radar functions including ...
Sponsored by:

Press Releases


Curtiss-Wright Corporation today announced that its Defense Solutions division has received a contract from Sierra Nevada Corporation (SNC) to supply its small form factor ...

Innovative Integration Announces the FMC-Servo

Camarillo, CA June 19, 2015, Innovative Integration, a trusted supplier of signal processing and data acquisition hardware and software solutions, today announced the FMC-S...


Curtiss-Wright Corporation today announced that its Defense Solutions division has further enhanced its innovative VRD1 high definition (HD) video management system (VMS) w...

All Access Sponsors

Mil & Aero Magazine

August 2015
Volume 26, Issue 8

Download Our Apps




Follow Us On...


Military & Aerospace Electronics

Weekly newsletter covering technical content, breaking news and product information

Cyber Security

Monthly newsletter covering cyber warfare, cyber security, information warfare, and information security technologies, products, contracts, and procurement opportunities

Defense Executive

Monthly newsletter covering business news and strategic insights for executive managers

Electronic Warfare

Quarterly newsletter covering technologies and applications in electronic warfare, cyber warfare, optical warfare, and spectrum warfare.

Embedded Computing Report

Monthly newsletter covering news on embedded computing in aerospace, defense and industrial-rugged applications

Unmanned Vehicles

Monthly newsletter covering news updates for designers of unmanned vehicles