Radar systems provide all-weather, day & night sensing and ranging by transmitting a radio-frequency (RF) signal, a part of which is reflected from the target or area of interest back to the radar system. The range-resolution of the radar is inversely proportional to the bandwidth of the transmitted signal, so a high-resolution radar requires a large bandwidth. In SAR imaging, a fine azimuth resolution is achieved through the coherent combination of multiple pulses from across the radar platforms path while a target is within the radar beam. The large bandwidths required for high-resolution SAR imaging are typically achieved at higher frequencies. The sensitivity of a radar system is another key performance parameter, and is dependent on system and scenario parameters such as antenna-gain, transmit-power, range-to-target, frequency, and receiver noise characteristics. Increasing the power output of the transmitter can improve radar performance. SSPAs are increasingly being used in radar applications, replacing older technologies such as traveling-wave-tube amplifiers (TWTAs). SSPAs are typically more efficient at lower frequencies, but modern Gallium Nitride (GaN) monolithic microwave integrated circuit (MMIC) technology allows for higher efficiencies at these frequencies, compact packaging, and higher reliability. ARTEMIS, Inc. proposes to develop, design, and demonstrate SSPA technology with high-efficiency and compact SWaP, operating with wide bandwidth at Ku-band. We will leverage our SSPA technology experience developed through over a decade of work with T/R modules and small-SWaP SSPAs which have been part of our past radar projects, including our next-generation SlimSDR radar system development (Army C5ISR Airborne Radar Branch, Phase II Sequential and AFRL/RWWI Phase II). In Phase I, ARTEMIS will create a detailed design of the Ku-band SSPA and show how the design meets the system requirements from the SBIR topic. We have already found a commercially available 70-Watt, 40-volt GaN HEMT MMIC die suitable for this application with delivery from stock. ARTEMIS will acquire the parts and work detailed design and packaging so that Phase I can culminate in a Detailed Design Review from which prototyping and building can commence in Phase II. Phase II consists of building and demonstration of the SSPA prototype. The SlimSDR can be used as a stand-in for other radar systems, and, as a bonus, this SSPA will add exquisite Ku-band capabilities to the SlimSDRs already formidable portfolio of functions. SSPA performance will be demonstrated through lab tests and flight tests, including SAR imaging, on ARTEMIS test-bed aircraft. Plans for application-specific qualification testing will be completed along with transition plans. The plans and prototype will be delivered to the Navy. The proposed technology will be useful for a wide variety of radar and RF systems, including extreme-environment applications (missiles/hypersonics).
Benefit: The final result of the Phase I research will be the Ku-band 200-Watt SSPA design with plans in motion to produce the prototype system in Phase II. Additionally, the detailed system performance parameters to be tested on the Phase II prototype will be provided. ARTEMIS will also complete a full work plan for Phase II so that work can begin immediately for building the prototype SSPA system and testing it in the lab and on ARTEMIS test-bed aircraft. The development of a small, affordable, highly-efficient Ku-band SSPA suitable for use with various radars in multiple modes and functions will invite widespread use across government and commercial concerns. When paired with flexible systems, such as the software-defined SlimSDR, the system is in a position to supplement and replace traditional systems (of various types) many times its size and cost. The new system will be applicable to many imaging applications and many aircraft (manned and unmanned) or missile platforms as well. Such applications include foliage penetration, pattern of life monitoring, targeting, and anti-terrorism. The technology will also be much easier to manufacture than traditional radar due to the fact that the design is well suited for automated electronics manufacturing. This all will contribute to providing the capabilities that multi-mode RF offers to new markets that were not achievable with previous radar designs. ARTEMIS will develop the new multi-mode, multi-function system to incorporate US and International standards, such as STANAG and JAUS, to ensure the system will easily integrate into existing and future platforms. For commercialization, ARTEMIS will use its 20 years of radar development, manufacturing, and sales/customer base to quickly bring the system to market. ARTEMIS is strongly positioned to fully realize the market for this new SSPA technology. The small-SWaP, high-efficiency SSPA will be used on manned and unmanned aircraft and missiles. The weapons market is steady, and the ISR sensor market, especially for unmanned systems is predicted to significantly grow over the next decade, even though budgets around the globe are shrinking. The need to do more with less is forcing mission planners to seek methods and sensors that incorporate as much capability as possible. This positions the proposed SSPA system to be an attractive option, with multiple intended modes and a light footprint. ARTEMIS will focus on several markets. For the military, in will be the maritime surveillance, force protection, weapons, UAS, and special mission market. For the civilian market it can be used effectively by emergency personnel, first responders, and disaster relief. The SSPA technology is suitable for UAS ISR and navigation, collision avoidance, weather, law enforcement, environmental monitoring, commercial aviation, border patrol, etc.
Keywords: Transmitters, Transmitters, microelectronics, Microwave Power Modules, Monolithic Microwave Integrated Circuit, GaN MMIC, Radar, solid state power amplifier, Microwave Electronics
