SBIR-STTR Award

Linearizer Technology, Inc. (LTI) proposes to produce an L-band GaN HPA exceeding GPS requirements with the highest possible power added efficiency (PAE) for use in space. Minimizing HPA cost will also be a primary design parameter. LTI"s mission is the production of flight hardware. It has significant experience with flight HPAs and currently has 100 linearizers and HPAs in orbit. LTI has demonstrated its ability to provide a UHF space PA with the highest PAE reported in the literature. LTI"s work at UHF has shown that the key factors to achieving high efficiency are 1) device selection and 2) circuit topology. Its UHF PA required a higher linearity than specified for GPS. However, GPS still needs some linearity. Although this requirement is minimal, even small improvements in space can be important. LTI will use its expertise in linearization to give its HPA design a PAE advantage. It already has a design for an L-band HPA meeting the power and PAE goals using U.S. made Gallium Nitride (GaN) devices. In Phase I, LTI will exploit its GaN HPA experience to produce a demonstration HPA exceeding the design goals. In Phase II, LTI will design and fabricate a space-qualified HPA.

Benefit:
LTI"s commercialization strategy is to become a highly cost competitive source of L-band satellite HPAs. This work will complement LTI"s space payload development plans. LTI produces RF and microwave hardware for use on satellites. LTI specializes in the production of linearizers and linearized power amplifiers for use on satellites. It has developed a relationship as a qualified supplier with several satellite manufactures and is working to expand these relationships. The successful completion of this project is anticipated to greatly enhance this business. The L-band HPA designed specifically for GPS satellite applications resulting from this work will open a huge market to LTI. (Just the current space linearizer market is estimated at more than 250 million dollars.) LTI has the facilities to produce and test ((including vibration and thermal-vac) space products. LTI's past support of the space/communications market has helped bring innovative and successful hardware to the marketplace. LTI is confident this project will lead to yet another successful endeavor. Unlike many small businesses, LTI is fortunate in that their existing staff presently supports a Marketing Department. Marketing Staff consists of a Marketing Manager, a graphic artist and a Marketing Assistant. Advertising campaigns are carefully planned and executed, and efforts in this area have been very successful. LTI has regularly exhibited at Satellite Exhibitions and the IEEE sponsored MTT IMS exhibitions. Advertisements have been placed in various industry magazines and the technical staff has published multiple articles. LTI remains very well aware of the customer base as well as the specific needs of the market place. Since ads and company literature are designed (and printed) in house, LTI already has the backbone in place to launch an extensive marketing campaign.

Keywords:
High Power Amplifier

Linearizer Technology, Inc. (LTI) and its space hardware organization Linear Space Technology, LLC (LST) propose to produce an L-band GaN high power amplifier (HPA) exceeding GPS requirements with the highest possible power added efficiency (PAE) for use in space. Minimizing HPA cost is a primary design parameter. LST has significant experience with flight HPAs and has 100 linearizers and HPAs in orbit. LTI/LST has demonstrated its ability to provide a UHF space PA with the highest PAE reported in the literature. LTI/LSTs work at UHF has shown that the key factors to achieving high efficiency are device selection and circuit topology. Its UHF PA required a higher linearity than specified for GPS. However, GPS still needs some linearity. Even small improvements in space can be important. LTI/LST will use its expertise in linearization to give its HPA design a PAE advantage. It has designed an L-band HPA meeting power and PAE goals using U.S. made Gallium Nitride (GaN) devices. In Phase I, LTI/LST exploited its GaN HPA experience to produce a demonstration HPA exceeding design goals. LTI/LST will use its knowledge of space hardware to insure a qualifiable design. In Phase II, LTI/LST will design and fabricate a space-qualified HPA.

Benefit:
Highly efficient high power amplifiers (HPAs) are needed for the transmission from satellites of GPS signals at L-Band. Present transmissions require relatively low linearity (AM/PM < 2.5 dB/deg.) but a high power (400 watts). The proposed HPA will take advantage of recent technical advances in solid-state device efficiency resulting from the introduction of space-qualified Gallium Nitride (GaN) HEMTs. Linearizer Technology, Inc. with its space hardware organization Linear Space Technology, LLC (LTI/LST) will use linearization to gain an advantage in power added efficiency (PAE) over non-linearized HPAs. Linearization will also allow the proposed HPA to function efficiently with new modulation formats under consideration that will require higher linearity. LTI/LST will use its relatively small size and the 300 plus years of spacecraft manufacturing experience of its staff to control costs. Its Phase I demonstration HPA has met or exceeded all design goals, and offers the following features: Flight qualified GaN power HEMTs selected for highest efficiency Predistortion linearization for improved AM/PM performance resulting PAE advantage and ability to efficiently operate with potential future modulations. Commandable saturated power over a 5 dB range Common packaging design that allows operation at GPS L1, L2 or L5 frequencies Command and control electronics with proven radiation hardness Surface-mount architecture with stripline combiners providing sufficient multipactor tolerance