ABSTRACT: A low-voltage wideband downconverter along with an integrated transformer RF balun using the 2 mum GalnP/GaAs HBT technology is demonstrated. This transformer is a symmetric type and plays a role as a single-to-differential balun. Without the parasitic between the transformer and the substrate, the transformer can work at higher frequencies. This transformer downconverter operates from 1.5 to 14 GHz with around 20 dB conversion gain and 1.8 GHz IF 3 dB bandwidth. The frequency range of the mixing operation is wide and covers the digital video broadcasting via satellite (DVB-S) bands. This mixer is therefore useful for DVB-S applications.
Electronics Letters 02/2008; · 0.96 Impact Factor
ABSTRACT: A single-ended wideband downconversion Gilbert micromixer is demonstrated in this paper using 0.35-mum SiGe BiCMOS technology. A transimpedance amplifier with resistive feedback is utilized in the IF stage while a broadband Marchand balun is employed to generate wideband differential local oscillator signals. The planar Marchand balun topology employed in this paper can generate truly balanced signals even in the presence of the lossy low-resistivity (~10 Omegamiddotcm) silicon substrate. A systematic approach to measure the frequency response of each individual stage in a Gilbert mixer is developed in this paper. This single-ended wideband mixer has the conversion gain of 15 dB, IP<sub>1dB</sub> of -19 dBm, IIP<sub>3</sub> of -7 dBm, and the noise figure of 13 dB. The mixer works from 3.5 to 14.5 GHz
IEEE Transactions on Microwave Theory and Techniques 01/2007; · 1.85 Impact Factor
ABSTRACT: Two general crossbar switch models are proposed: the modified
one-sided crossbar switch and the ripple K one-sided crossbar switch.
They both balance cost and reliability, where cost is expressed in terms
of crosspoint count or area. The two-sided crossbar switch and the
one-sided crossbar switch are two cases of these structures. These
structures provide choices for compromising structures between the
two-sided crossbar switch and the one-sided crossbar switch. The
effective bandwidths of these four crossbar switches are simulated.
Simulation with VHDL has been performed to verify the functionality of
each crossbar system. Synthesis has also been conducted to evaluate
delay and area for each crossbar design. Experimental results
demonstrate that the two general models of crossbar switches are
cost-effective in terms of reliability and crosspoint count (or area)
without reducing their effective bandwidths. The work promotes the use
of the crossbar switch as an interconnection network for multiprocessor
systems to enhance system performance and reliability with low
IEE Proceedings - Computers and Digital Techniques 02/1999;