Theory and Design of Low-Noise Multipath Amplifiers
| Autor: | Barend Visser, Ocker C. de Jager, Petrus Paulus Kruger |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Engineering
Open-loop gain Radiation business.industry Distributed amplifier Y-factor Distributed amplifiers Condensed Matter Physics Fully differential amplifier Low-noise amplifier multipath amplifier (MPA) noise cancellation Electronic engineering Effective input noise temperature Instrumentation amplifier microwave amplifier Electrical and Electronic Engineering low-noise amplifiers business Direct-coupled amplifier |
| Zdroj: | IEEE Transactions on Microwave Theory and Techniques. 59:414-424 |
| ISSN: | 1557-9670 0018-9480 |
| DOI: | 10.1109/tmtt.2010.2095878 |
| Popis: | The theoretical minimum noise measure of a multipath amplifier (an amplifier that has multiple parallel amplifiers) is achieved by using the optimum source impedance and optimum gain for each amplification path. This optimum source impedance and gain can be calculated by replacing each amplifier with its optimum source impedance. The resulting noise measure is the same as the minimum noise measure of the amplifiers used. The theory is demonstrated by applying it to distributed am plifiers. In an ideal distributed amplifier, the magnitude of the optimum gain of the amplification paths decreases and the phase delay increases the farther the stage is from the input, with the decrease in gain being faster for higher frequencies. The challenge in designing broadband low-noise distributed amplifiers is to achieve optimum gain matching over broad bandwidths. A numerical optimization procedure that separates source impedance and gain matching is proposed and demonstrated by optimizing a 0.5-2-GHz distributed amplifier. An average noise measure of 0.3 dB is achieved, which is only 0.1 dB higher than the minimum noise measure of the amplification stages used. This increase is due to transmission line loss and gain mismatch. http://dx.doi.org/10.1109/TMTT.2010.2095878 Sponsored by : IEEE Microwave Theory and Techniques Society |
| Databáze: | OpenAIRE |
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