Frequency analyzer comprising a digital band-pass and a digital low-pass filter section both operable in a time-division fashion
US4157457A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1978 |
| Grant date | Jun 5, 1979 |
| Priority date | — |
| Expiry date | Mar 6, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A frequency analyzer of a predetermined number of channels comprises a digital band-pass and a digital low-pass filter section. A preselected number of digital samples sampled with a sampling period are stored in a buffer memory to be read out in each sampling period. A band-pass parameter memory memorizes for the respective channels band-pass filter impulse responses, each having preselected values, equal in number to the preselected number. A band-pass filter calculator calculates a convolution of each read-out digital sample and the preselected values of each response. The low-pass filter section produces frequency analysis results for the respective channels in each analyzing frame period equal to a first prescribed number of the sampling periods. A low-pass filter impulse response having a duration equal to the frame period multiplied by a second prescribed number and prescribed values, the predetermined number in each sampling period, is memorized in a low-pass parameter memory with its phase or the duration successively shifted by the frame period. A multiplier calculates products of each convolution and the prescribed values of the respective memorized responses read out in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.