Characteristics of LNA Operation in Direct Delta–Sigma Receivers

Autor:	Kimmo Koli, Kim B. Ostman, Mikko Englund, Kari Stadius, Jussi Ryynanen, Olli Viitala
Rok vydání:	2014
Předmět:	Engineering business.industry Preamplifier Electrical engineering Delta-sigma modulation Noise (electronics) Low-noise amplifier law.invention law Integrator Electronic engineering Operational amplifier Output impedance Electrical and Electronic Engineering business Voltage
Zdroj:	IEEE Transactions on Circuits and Systems II: Express Briefs. 61:70-74
ISSN:	1558-3791 1549-7747
DOI:	10.1109/tcsii.2013.2291092
Popis:	This brief analyzes the dual role and operation of the low noise amplifier (LNA) in the recently introduced direct delta-sigma receiver (DDSR). First, the LNA functions as a transconductor in an integrator stage, and in this role, we explore the effects of LNA output impedance on quantization noise shaping by the system. In the second role of a voltage preamplifier, we show how the closed-loop DDSR structure impacts LNA voltage gain and system noise. LNA and system properties are thus intertwined and lead to the need for careful codesign. The reliability of the utilized continuous-time DDSR approximation is verified by simulating a sample receiver model.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c54c53f426be6534a3ba3fe96eb03a7c https://doi.org/10.1109/tcsii.2013.2291092 Zobrazit plný text záznamu