SBIR-STTR Award

Power amplifiers (PAs), providing high linearity and efficiency, are essential for transmission of high data rate bandwidth efficient digital signals. Achieving this objective at millimeter-wave (MMW) is particularly challenging. LTI with L-3 EDD are teaming to develop a PA for 81-86 GHz with a linear output power of 50 watts, a PAE of 30%, and a weight of 10 lbs. Linear performance is based on an ACPR < -30 dB with 12/4 QAM. A goal is to achieve this ACPR at 3 dB OPBO. The PA will use a 100 watt EDD W-band TWTA scaled down in frequency from 94 GHz and optimized for efficiency. LTI will provide the linearizer. LTI has experience producing MMW linearizers and has demonstrated an ACPR < -45 dB with 16QAM at 7 dB OPBO. Based on this result, an ACPR of 30 dB at 3 dB OPBO looks quite achievable. In Phase I, EDD will determine changes needed for 81-86 GHz operation of their TWTA, simulate its performance, and begin design of the EPC and housing. LTI will design and test the linearizer, with the goal of testing with EDD’s existing W-band TWTA.

Benefit:
This technology has value for space-borne and airborne platforms, as well as ground-based systems. This work will result in the first W-band MPM ever produced. It will also provide a key component in the production of compact, efficient, linear power amplifiers to meet the needs of SATCOM and related space-borne communications, and for which no alternative solution currently exists.

Keywords:
Mpm, Twta, High Power Amplifier, Linearizer, Predistortion, Efficiency, W-Band, Millimeter-Wave

Linearizer Technology-GOV with L-3 Communications EDD proposes to produce a 100W power amplifier covering the 81 to 86 GHz band with the goal of a linear output power of 50W at a power efficiency of 20%, > 30% PAE with additional TWT development. The HPA?s linear power is based on an adjacent channel power ratio of < -30 dB at a 1 symbol rate spacing with a 12/4 APSK modulated carrier, which will be achieved at an output power backoff from saturation of less than 3 dB. The HPA will be in the form of a linearized MPM with < 16 lbs, and designed to operate up to 80º C. The final amplifier stage is a TWT employing a robust, all-metallic circuit from the coupled cavity family. LTI has developed a predistortor with the nonlinear characteristics needed to linearize 92 to 96 GHz W-band TWT. Integration and test with the TWT is planned for January 2013. LTI is designing a linearizer operating with a TWT 81 to 86 GHz, and has demonstrated appropriate correction characteristics for this band. The design of this linearizer and the W-band TWT for operation at 81 to 86 GHz will be completed in phase I.

Benefit:
This technology has value for both space-borne and airborne platforms, as well as ground-based systems. This work will result in a new baseline for W-band HPA efficiency and linearity. It will also provide a key component in the production of compact, efficient, linezr HPAs to meet the needs of SATCOM W-band AISR communications, for which no alternative solution currently exists.

Keywords:
W-Band, Mpm, Linearizer, Millimeter Wave, Efficiency, Hpa, Qam, Apsk