Microwave/millimeter wave amplifier with RF feedback
US4525680A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1983 |
| Grant date | Jun 25, 1985 |
| Priority date | — |
| Expiry date | Apr 22, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/601
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An RF MESFET amplifier having a feedback resistor further incorporates two sets of quarter wavelength low impedance pads and quarter wavelength high impedance lines in the resistor feedback path. These RF impedance elements prevent RF feedback as well as thermal noise generated by the feedback resistor from being coupled to the input. Moreover, they effectively isolate RF interaction between the drain and gate of the MESFET; as a result, the amplifier has excellent stability. The low impedance quarter wavelength pads serve as an RF bypass (to ground), while the high impedance quarter wavelength lines provide high attenuation near frequencies at the given wavelength. Consequently, thermal noise generated by the feedback resistor will be bypassed to ground and will not leak into the gate. The value of the feedback resistor can be selected and optimized to obtain the desired VSWR, bandwidth and gain flatness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.