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Chung Y.,Wavestream | Deckman B.C.,Wavestream | DeLisio M.P.,Wavestream
Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC | Year: 2012

This paper presents the design and performance of an X-band GaAs FET power amplifier (PA) system with 100-W of saturated output power. A simple and cost-effective predistortion linearizer is developed to increase the linear output power of the PA system. To spatially combine output powers of GaAs FETs and to launch output signals directly into the WR-112 waveguide, the PA uses a pair of microstrip-to-coaxial transition probes. Measurement shows that linearization significantly reduces the PA's nonlinear signal distortions, resulting in a 3 dB increase of operating linear output power. © 2012 IEEE.

Than H.T.,Wavestream | Sun G.W.,Wavestream | Cuellar G.S.,Wavestream | Zeng J.,Wavestream | And 5 more authors.
IEEE Journal of Solid-State Circuits | Year: 2012

This paper describes the design and performance of a $C$-band amplifier with over 600 W of saturated output power . This amplifier is intended for use in commercial broadcast satellite uplink base stations. The amplifier uses spatial power combining to combine the output powers of sixteen internally matched 45-W GaAs FETs. The amplifier also comprises pre-amplification and driver amplification stages, a level control variable attenuator, and a predistortion linearizer. The unit also includes a power supply as well as a user monitor and control interface. We will present various measures of this amplifier's linearity performance, demonstrating its suitability for use in broadcast applications. Finally, we will present results from power combining two of these amplifiers, resulting in a solid-state amplifier with 1.4 kW of saturated $C$-band output power. © 1966-2012 IEEE.

Chung Y.,Wavestream | Deckman B.C.,Wavestream | Delisio M.P.,Wavestream
Microwave and Optical Technology Letters | Year: 2013

This letter presents a simple and compact design approach for broadband analog phase shifters and its demonstration. An octave bandwidth can be obtained by alternately cascading low-pass filters (LPF) and high-pass filters (HPF) that importantly provide complementary phase-changing characteristics over "frequencies." Achievable phase change per segment can be multiplied by cascading multiple segments that operate as independent phase shifters, thereby reaching 360 degrees of phase shift. We demonstrate one- and two-segment phase shifters consisting of cascaded LPF-HPF-LPF structures, of which capacitors in each filter are implemented by varactors, over a frequency range from 0.7 GHz to 1.4 GHz. Measurements show 65.8 degree average phase shifts from the single-segment and 128 degree from the double-segment, which is about twice as much as the single-segment shifter's. © 2012 Wiley Periodicals, Inc.

Wavestream | Date: 2011-01-28

The present invention pertains to a pre-distorter linearizer that incorporates a balanced-to-unbalanced transmission line transition as a phase shifter to feed the linear and non-linear arms of the linearizer with signals of substantially the same amplitude and with a frequency-independent and substantially 180-degree phase difference. Preferably the balanced-to-unbalanced transmission line transition is a slotline-to-microstrip transition. Several alternatives are shown to enhance the bandwidth performance of the linearizer. Using a slotline-to-microstrip transition as a phase shifter provides for a very physically compact and inexpensive design. Furthermore, the flexibility of the slotline-to-microstrip architecture allows the linearizer to be easily integrated into systems that use both solid-state and vacuum-tube amplifiers.

Wavestream | Date: 2011-12-16

An active denial apparatus for use in non-lethal weaponry includes at least one focusing element configured to focus millimeter-wave energy along an axis of propagation. The at least one focusing element includes an astigmatic or dual axis focusing system configured to direct a focused beam that allows the active denial apparatus to accurately immobilize targets at both close and long range within acceptable limits of intensity.

Wavestream | Date: 2010-02-10

An active denial apparatus comprising a high-power millimeter wave source and at least one beam-processing element for directing millimeter wave energy along an axis of propagation, the at least one beam-processing element including a variable focusing system configured to be cycled through at least two focusing configurations.

2016117 admin 18.com3 ...

Wavestream | Date: 2010-08-10

Satellite communications amplifiers.

Wavestream | Date: 2012-12-04

Amplifiers for airborne satellite communications.

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