Gain-boosted N-path bandpass filter
US9374063B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 2015 |
| Grant date | Jun 21, 2016 |
| Priority date | — |
| Expiry date | Jun 1, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2210/025
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention discloses a gain-boosted N-path SC bandpass filter (GB-BPF) with a number of sought features. It is based on a transconductance amplifier (Gm) with an N-path SC branch as its feedback network, offering 1) double RF filtering at the input and output of the Gm in one step; 2) customized passband gain and bandwidth with input-impedance match, and 3) reduced physical capacitance thanks to the loop gain offered by Gm. All have been examined using a RLC model of the SC branch before applying the linear periodically time-variant (LPTV) analysis to derive the R, L and C expressions and analytically study the harmonic selectivity, harmonic folding and noise. The latter reveals that: 1) the noise due to the switches is notched at the output, allowing smaller switches to save the LO power; and 2) the noises due to the source resistance and Gm are narrowband at the output, reducing the folded noise during harmonic mixing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.