Radio receiver blanker gate
US4203073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1978 |
| Grant date | May 13, 1980 |
| Priority date | — |
| Expiry date | Feb 6, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/345
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A balanced, doubly tuned gate couples between the mixer and intermediate frequency (IF) stages of a conventional radio receiver. The network is comprised of a pair of matched transformers interconnected in a balanced configuration, with the first transformer tuned to the mixer and the remaining transformer tuned to the IF stage. Capacitors interconnect the two transformers resulting in a Butterworth filter network. Two diode pairs connect in shunt across selected windings of the transformers. Direct current bias normally biases the diodes to a nonconducting state, thereby allowing the mixer signals to pass to the IF stage. A blanking signal from the receiver blanker drives the diodes to conduction thereby decoupling the mixer from the IF and blanking the receiver. Due to the doubly balanced nature of the gate, blanking is accomplished with a minimum of switching time. Moreover, the shunt diode switching scheme provides superior attenuation in the blanking mode and enhanced operation in the normal mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.