Michael P. DeLisio

A Ka-band grid amplifier module with over 10 Watts output power

We present a Ka-band grid amplifier power module. The module is fully packaged with waveguide input and output flanges. It includes a driver grid amplifier chip for gain, followed by a booster grid amplifier chip for power. With a 50/spl deg/C baseplate temperature, the module has a small signal gain of 12 dB. The single-chip output booster stage delivers over 16 Watts of saturated power. The module delivers over 10 Watts output with a constant 1.6 Watts input over a 550 MHz bandwidth. We also present a large-signal third-order intermodulation and AM/PM conversion measurements, which are consistent with expectations. To our knowledge, this is the highest power ever reported from a monolithic single-chip power amplifier at Ka-band.

Design and Performance of a 600-W

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 amplifiers 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.

C

The first monolithic grid amplifier using a cascade differential-pair amplifier unit cell has been designed and measured. The grid is packaged using reflection architecture with waveguide input and output. The measured gain at 82 GHz is 5.5 dB. The measured output power is 110 mW with 2.5 dB residual gain. The size of the amplifier module is 20 mm/spl times/10 mm/spl times/10 mm.

-Band Amplifier Using Spatially Combined GaAs FETs for Satellite Communications

This letter presents a 79-GHz broadband reflection-type grid amplifier using spatial power combining to combine the power of 64 unit cells. Each unit cell uses a two-stage cascade configuration with InP HEMTs arranged as a differential pair. A broadband orthogonal mode transducer (OMT) separates two orthogonally polarized input and output signals over a 75 to 85GHz range. In conjunction with the OMT, a mode converter with quadruple-ridged apertures was designed to enhance the field uniformity over the active grid. Measurements show 5-dB small signal gain at 79GHz and an 800-MHz 3-dB bandwidth. The amplifier generates an output power of 264mW with little evidence of saturation.

A single chip two-stage W-band grid amplifier

By spatially combining the outputs of many solid-state devices on a single chip, grid amplifiers are not only powerful, linear, and efficient, but also are compact, rugged, and robust. We present measured data from a fully-packaged Ka-band module with standard waveguide input and output flanges. With a 50/spl deg/C baseplate temperature, the module can be biased to deliver from 10 to 16 Watts of rated output power in the 30-31 GHz band. The module exhibits very good spectral regrowth performance, and can be operated well into saturation in single-carrier terminals for shared-spectrum multiple-access applications.

W-band waveguide-packaged InP HEMT reflection grid amplifier

This paper describes the design and performance of a C-band amplifier with over 600 Watts 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 amplifiers linearity performance, demonstrating its suitability for use in broadcast applications.

Power and spectral regrowth performance of 10-W and 16-W Ka-band power amplifiers with single-chip output stages

Active grids are periodic structures loaded with transistors or diodes that interact with electromagnetic beams. These new quasi-optical components may make possible a new generation of low-cost, high-power solid-state millimeter-wave communications, broadcast, and radar systems. Quasi-optical power combining allows the output power from large numbers of individual transistors and diodes to be combined in free space without transmission-line losses. These components can often be made as planar structures that are suitable for large-scale monolithic integration. A variety of grids have been demonstrated, including detectors, phase shifters, multipliers, oscillators, and more recently, amplifiers and switches. In these grids, the power is proportional to the area, while the circuit impedances are determined by the dimensions of the unit cell. This allows great design flexibility. One can achieve high power and high efficiency simultaneously, or large dynamic range and low noise at the same time. The authors discuss the results for several grids. The first is a a doubler with an output power of 330 /spl mu/W at 1 THz. The second is a 10/spl times/10 pHEMT hybrid grid amplifier with a 3 dB noise figure and 3.7 W output at 10 GHz. They also discuss current results on monolithic grid amplifiers for millimeter wavelengths.

A 600-W C-Band Amplifier Using Spatially Combined GaAs FETs

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 PAs nonlinear signal distortions, resulting in a 3 dB increase of operating linear output power.