Digitally controlled monolithic active phase shifter apparatus having a cascode configuration
US4994773A · kind A · utility
Inventors
Key dates
| Filing date | Oct 13, 1988 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | Oct 13, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/20
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digitally controlled active phase shifter with vernier control consists of a 180 degree phase bit in series with a 90 degree bit and a digitally controlled active vector generator with vernier control. The digitally controlled active vector generator consists of an active power divider with digitally adjustable amplitude, a pair of phase delay networks with an active power combiner employing vernier control. The power divider consists of two sets of parallel pairs of FET's in cascode configuration with all input nodes connected together and all output nodes from the same set tied together. The FET at the output node of each pair is a common gate configuration with its gate RF grounded through a bypass capacitor. The gate bias voltage is applied to the common gate FET to switch it ON or OFF to thereby provide a set of desired signal amplitudes which can be obtained by selecting the gain of each of the cascode stages in each of the parallel pairs. Two output signals from the power divider are fed into a pair of phase delay networks to get 90 degree phase differences. The two 90 degree out of phase signals are then combined by an active power combiner which consists of two pairs of …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.