Analysis and Design of N-Path Filter Offset Tuning in a 0.7–2.7-GHz Receiver Front-End
| Autor: | Jussi Ryynanen, Mikko Kaltiokallio, Mikko Englund, Kimmo Koli, Olli Viitala, Kari Stadius, Kim B. Ostman |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
linearity
Engineering Offset (computer science) N-path filtering ta221 Hardware_PERFORMANCEANDRELIABILITY Blockers Parasitic capacitance RF front-ends Hardware_INTEGRATEDCIRCUITS Electronic engineering ta318 complex filtering Electrical and Electronic Engineering Wideband Center frequency ta216 low-noise amplifiers ta116 receivers ta213 ta114 business.industry CMOS Electrical engineering Input impedance Filter (signal processing) circuit optimization quadrature Baseband business |
| Zdroj: | IEEE Transactions on Circuits and Systems I: Regular Papers. 62:234-243 |
| ISSN: | 1558-0806 1549-8328 |
| DOI: | 10.1109/tcsi.2014.2358331 |
| Popis: | N-path techniques have become a popular candidate alternative to external pre-selection filtering in wireless receivers. Their main attraction lies in enabling tunable on-chip high- $Q$ filters, with straightforward migration from one CMOS node to another. However, parasitic capacitance at the N-path filter input offsets the bandpass response from the desired center frequency in wideband circuits. In this paper, we focus on an LNA-first receiver and show that the offset at the LNA output varies in magnitude depending on LNA and filter load impedance properties. An offset-tuning approach is then evaluated for its effects on receiver gain and noise and to obtain design guidelines. We propose a digitally controllable implementation that preserves front-end gain and linearity, with a small penalty on receiver NF. A programmable 0.7–2.7-GHz front-end in 40-nm CMOS verifies the functionality. At 1.7 GHz, the front-end has a gain of 37 dB, a NF of 5.2 dB, and an out-of-band IIP3 of $+$ 1 dBm. |
| Databáze: | OpenAIRE |
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