180 degree phase shifter bit
US5334959A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1993 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Apr 15, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved 180.degree. phase shifter bit that uses embedded switches to selectively connect the RF input and RF output to a loosely coupled transmission line segment and a pi section of transmission line. A hybrid coupler is selected having characteristic impedance of less than 50 ohms and having coupling of less than -3 db. The result of this coupling choice is extremely low insertion loss. The resultant impedance mismatch is compensated for by providing oversized field effect transistors that allow RF signal in both the grounded coupler and the pi section of transmission lines that are 180.degree. out of phase. The RF signal present in both the coupler and pi section of the transmission line results in a cancellation effect allowing recovery of the input/output impedance over an approximately one octave bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.