Zero IF radio receiver apparatus
US4736390A · kind A · utility
65Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1986 |
| Grant date | Apr 5, 1988 |
| Priority date | — |
| Expiry date | Oct 15, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/30
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
There is described a zero IF receiver which affords to reduce offsets normally associated with quadrature mixers employed in such receivers. In order to reduce the effect of such offsets the local oscillator signal is modulated with a balanced pseudo-random phase code signal. This signal is then stripped off by means of additional mixers, one for each of the quadrature channels. The effect of the pseudo-random phase code signal is to spread the spectrum which is associated with the offsets so that the receiver can now respond to desired signals with a minimum of interference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.