Amplifying unit comprising an input transformer capable of contributing to a wider frequency band of a broadband amplifier
US6111465A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1997 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Oct 9, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/534
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An input transformer, used as a transmission-line transformer (11), is provided for connection between an unbalanced transmission line (10) and a balanced broadband amplifier (12), in which the input transformer has a fixed middle potential. The transmission-line transformer (11) converts an input signal into two output signals having opposite phase with respect to each other and which are supplied to the broadband amplifier (12). It is therefore possible to cancel secondary distortion in an amplifying unit. As the transmission-line transformer (11) a forced-balun type transmission-line transformer is used which has two input ports (P1, P2) and three output ports (P3, P4, P5), one (P4) of which is grounded. First and second two-wire parallel lines are arranged between the input ports and the output ports via a single glasses-shaped core. The input port and the two output ports have a respective impedance ratio of 1:(1/2):(1/2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.