0000000000263984
AUTHOR
B. Di Maio
HEMT for low-noise microwaves: CAD-oriented performance evaluation
This paper shows how a graphic processing of low-noise HEMT's small signal parameters, allows evaluating and comparing the actual performance obtainable in front-end applications. HEMT's tradeoff charts which solve tradeoffs among the basic low-noise amplifier performance are reported. Figures of merit for microwave low-noise HEMT which represent a fast way of evaluating HEMT in actual working conditions and of selecting the proper transistor, are defined. As an example, the tradeoff charts and the figures of merit of two HEMT's (Fujitsu FHR02FH, Sony 2SK677) and a pseudomorphic-HEMT (Celeritek CFB001-03) are reported and compared with the data sheets. © 1995, IEEE. All rights reserved.
On the Theoretical Limits of Noise-Gain-Mismatch Tradeoff in the Design of Multi-Stage Cascaded Transistor Amplifiers
The problem of evaluating the limit performances of cascaded single-ended multi-stage transistor amplifiers is addressed. In particular, a theoretically rigorous approach is proposed for the determination of a family of optimal design curves (ODC's) which express the best (maximum optimal) noise-gain tradeoff that can be achieved - at each operating frequency - when a simultaneous constraint on amplifier input VSWR is accounted for.
On the optimal design of multi-stage cascaded transistor amplifiers with noise, gain and mismatch constraints
The problem of evaluating the optimal performances of cascaded, unbalanced, multi-stage transistor amplifiers is addressed. In particular, a theoretically rigorous approach is proposed for the determination of a family of Optimal Design Curves (ODC's) which express the best noise-gain tradeoff that can be achieved - at each frequency and device operating condition - when a simultaneous constraint on amplifier input VSWR is accounted for. Such curves can be used as a more meaningful starting point in practical amplifier design in place of the approximate calculations so far employed for target performance or optimization goals determination.