Frequency converter apparatus with distortion compensating circuit
US5715532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1996 |
| Grant date | Feb 3, 1998 |
| Priority date | — |
| Expiry date | Jan 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45251
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency converter may be employed in communication equipment such as a portable telephone. The frequency converter includes a differential pair consisting of first and second transistors, a current bypass circuit consisting of third and fourth transistors, and a distortion compensating circuit consisting of fifth and sixth transistors. The distortion compensating circuit decreases an emitter-to-base voltage of the sixth transistor when an emitter current of the first transistor is increased, while it increases an emitter-to-base voltage of the fifth transistor when an emitter current of the second transistor is decreased, non-linearts components of the emitter-to-base voltages of the first and second transistors caused by variations of RF (radio-frequency) signals inputted to the first and second transistors are called decreasing distortion of an output signal of the frequency converter caused by the difference in operating point between the first and second transistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.