Whether in the form of radar, satellite communications or electronic warfare, RF and microwave technologies have provided the military and the defense sector the components and systems needed to keep military operations at the forefront — and to help them achieve the dominance needed on the battleground.
While the enhancements have continued unabated, the recent war in Iraq and the looming threat of global terrorism after the Sept. 11, 2001, events have prompted the government to increase the pace of developments in the military segment. Consequently, the defense sector has stepped up its research and development (R&D) efforts to ensure that military operations are more advanced and better than ever. Hence, it is not surprising to see that the military budget has soared in the last few years.
Although military spending was cut drastically after the Cold War, it has re-emerged as government spending on smart weapons and information technology has increased substantially in the last few years. According to industry analysts, Department of Defense (DoD) spending is expected to reach $390 billion in fiscal 2003. R&D is said to be approximately 14% of this budget. Furthermore, analysts project that U.S. military spending could go as high as $434 billion by 2013. Military experts are foreseeing faster transition of technology from military R&D labs to the battleground.
To give the readers a good look at some of the latest developments on this front, Power Electronics Technology's Defense Electronics supplement has invited three companies to shed light on three new technologies that promise to boost military systems to new levels of unparalleled performance.
Peregrine Semiconductor Corp.'s Dan Nobbe will show how military GPS receivers can benefit from recent advances in RF CMOS silicon-on-sapphire (SoS) technology. Despite the system improvements and the ability to find and remove jammers, military GPS systems must be designed to handle jamming, whether intentional or unintentional. Anti-jam capability comes about through smart antennas and high dynamic range receivers. Peregrine Semiconductor has created a highly integrated dual-band anti-jam GPS receiver for these applications. Additionally, due to radiation-hardened properties of Peregrine's Ultra Thin Silicon (UTSi) process, this GPS receiver technology can also be extended to spacecraft applications. Nobbe will detail these advances in the article titled “Highly Integrated GPS Receiver Overcomes Jamming, Pinpoints Location.”
With the need for more bandwidth and security, military communications systems are driving the need for higher frequency amplifiers, especially in the Ka-band. In addition, Ka-band applications are demanding more power than afforded by modern solid-state power amplifiers. While conventional traveling wave tube (TWT) amplifiers can meet the frequency, power and reliability requirements of such applications, they do not provide the mass production benefits of microfabrication techniques. In the article “Microfabricated Next-Generation Millimeter-Wave Power Amplifiers,” Larry Sadwick, Jennifer Hwu and Dean Anderson will explore a new fabrication method and its impact on the performance of the Ka-band TWT power amplifier.
Unlike digital electronics, which has witnessed exponential improvements in the last two decades, analog has progressed at a much slower pace. Advances have been made in superheterodyne and direct conversion techniques, but the basic analog transmitter has changed little in almost 100 years. Transmitter frequency ranges and bandwidths have been limited by the use of band-specific analog components. These analog architectures require bulky and expensive microwave and RF components that consume significant levels of current, limit the functional bandwidth and adversely affect size and cost. Yet, they were deemed necessary to preserve the transmitted signal quality and linearity. These architectures are now hard-pressed to meet the wide bandwidth, smaller size and lower power consumption requirements of reconfigurable transmission systems. As bandwidths, data rates and operating frequencies increase, an even higher premium is placed on new transmitter architectures that promise lower power consumption. Digital circuitry is now capable of generating multimode, high bandwidth and programmable waveforms. In the article, “Digital Polar Design Facilitates Multimode Transmitters,” Steven Hurwitz of M/A-COM discloses a novel approach for “digitizing” almost all the analog and RF functionality of the transmitter. This digital transmitter is particularly useful in military applications, such as on the Joint Tactical Radio Systems (JTRS) Program and software-defined radio.