Microwave preamplifier
US4623848A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1984 |
| Grant date | Nov 18, 1986 |
| Priority date | — |
| Expiry date | Jul 16, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/60
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An input matching circuit for a first stage amplifying element of a microwave preamplifier comprises at least one capacitive open-ended stub which is located in the vicinity of an input terminal of the first stage amplifying element so that the structure of the input matching circuit is simple. Input impedance of the first stage amplifying element is designed to assume a state of impedance matching for minimum noise, while the distance between the first stage amplifying element and a second stage amplifying element is appropriately determined with an input matching circuit of the second stage amplifying element being appropriately set. With this arrangement input VSWR of the preamplifier is set to a value smaller than an input VSWR of the first amplifying stage, and therefore it is possible to provide a microwave preamplifier which shows satisfactory input VSWR characteristic and noise figure such that the input VSWR of the preamplifier is improved when compared with the input VSWR exhibited on impedance matching for minimum noise while the noise figure is less deteriorated compared to the noise figure exhibited on impedance matching for minimum noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.