Direct microwave modulation and demodulation device
US5122765A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 1989 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Dec 12, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2201/0208
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A microwave circuit intended for either direct modulation or direct demodulation of a microwave link communications signal is characterized in that a local oscillator (8) is incorporated in the circuit. The local oscillator supplies two signals that are in phase opposition at 180 degrees. Each signal is sent to a phase shifter. The first phase shifter (9) supplies two signals that are in quadrature, at 0 and 90 degrees. The second phase shifter supplies two signals in quadrature at 180 and 270 degrees. The 0 and 180 degree signals are sent to a first mixer (2), while the 90 and 270 degree signals are sent to a second mixer (3). In the case of a modulator, the first and second mixers receive, respectively, in-phase and quadrature signals, and the outputs of the mixers are combined to form a modulated signal. In the case of a demodulator, a modulated signal is applied through a .div.2 divider to inputs of the two mixers, and in-phase and quadrature signals are obtained at respective mixer outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.