Full flexible performance characterization of a feedback applied transistor with LNA applications |
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Authors: | Filiz Güneş Oktay Yurttakal |
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Affiliation: | Department of Electronics and Communication Engineering, Yıldız Technical University, Istanbul, Turkey |
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Abstract: | In this paper, the full flexible performance characterization of a transistor with series inductive/parallel capacitive feedback is carried out in terms of LNA applications. For this purpose, the input VSWR Vin–maximum available gain GTmax variations are constructed for a high technology low-noise transistor that is subject to the required noise figure Freq(f) ≥ Fmin(f) along the device's operation band depending on the feedback. These Vin–GTmax variations result in the application of a design chart that indicates which value of feedback can be applied within which region of the operation band with the improvable trade-off between the Vin and output VSWR Vout for the Freq(f) ≥ Fmin(f). Following this, the optimum trade-off between Vin and Vout is made for the necessary operation frequency regions using the load impedance ZL as an instrument with the predetermined source impedance ZS. Finally, the LNA applications of a series inductive/parallel capacitive feedback applied transistor with the optimum Vin, Vout, and GT subject to Freq(f) ≥ Fmin(f) ≥ are also presented as distributed across the entire bandwidth in the different operation bands. It can be concluded that this rigorous work will enable a designer to utilize the entire operation frequency band of transistor through using only a single series inductive/parallel capacitive feedback for the LNA designs of Freq(f) ≥ Fmin(f) with the optimum trade-offs among its performance measures. |
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Keywords: | feedback gain microwave transistor noise figure stability VSWR |
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