High speed monolithic microwave integrated circuit (MMIC) quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM) modulators
US7065153B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2002 |
| Grant date | Jun 20, 2006 |
| Priority date | — |
| Expiry date | Apr 19, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2064
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a system for modulating an RF carrier, the RF carrier is fed through a lowpass filter and phase shifted approximately −90 degrees. The RF carrier is also fed through a high pass filter and phase shifted approximately +90 degrees. A switch connected to the output of the lowpass filter and connected to the output of the highpass filter, selects and outputs either the −90 degree phase shifted carrier output from the lowpass filter or the +90 degree phase shifted carrier output from the highpass filter depending on a switching state determined by data bit information received at a data port to produce a BPSK modulated RF carrier. Two such BPSK modulators may be combined using lowpass and highpass filters to form a QPSK modulator. Two such QPSK modulators may be combined with an attenuator to form a QAM modulator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.