R. E. Leoni

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In this paper, we present the development of an even-mode matching network for a Marchand balun to achieve 50-¿ match and high isolation at the balanced ports. A very wide matching bandwidth can be accomplished with the novel addition of an open-circuit stub to the network. Experimental results demonstrate that the even-mode matched balun achieves return(More)
Metamorphic HEMT (MHEMT) technology is capable of providing InP based HEMT performance at GaAs based HEMT levels of manufacturability and cost. This makes the MHEMT an attractive alternative for low noise, high frequency, and wide bandwidth applications. The authors describe the performance of a DC-45 GHz MHEMT traveling wave amplifier (TWA) that is well(More)
This paper presents the design and development of a low-loss and wide-band width multilayered Marchand balun. The balun has been implemented using printed circuit board materials with integrated multilayered organic thin films. We have designed the top layer transmission lines on twin-thickness organic thin films to achieve low loss and wide bandwidth for(More)
In this paper, we present a wide bandwidth power amplifier (PA) utilizing a Marchand balun to achieve power combining and inverse class-F (class-F<sup>-1</sup>) matching. We have used a 4-to-1 balun and its out-of-band characteristics to achieve matching at the second and third harmonic for differential class-F<sup>-1</sup> operation. Thus, the balun(More)
This work developed a distributed PHEMT model for small signal S-parameter simulation. Distributed effects due to feed metalization were compared for a wide range of measured PHEMT geometries. Agreement between measured and modeled results was achieved for a large 40 x 60 /spl mu/m PHEMT, which makes the model attractive for large-signal model development.
High-speed metamorphic PIN diodes that absorb at 1.55 /spl mu/m wavelength light were fabricated on a GaAs substrate. The In/sub 0.53/Ga/sub 0.47/As-based top-illuminated structure showed a low, stable dark current of 7 nA at 10 V reverse bias. The packaged diode demonstrated a -3 dB bandwidth of 52 GHz and 0.52 A/W responsivity. This state-of-the-art diode(More)
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