| 摘要 |
The level changeover device includes first and second hybrid circuits (2, 5) incorporating two intermediate final stage modules (3, 4). A first changeover coupler (8) is couples the drive stage (1), in the high gain position, with the input side of the first hybrid circuit. A second changeover coupler (9) is arranged in a port balanced in connection to the second hybrid circuit in the high effect position in order to connect termination resistors (13) and in the low gain position to connect by-pass coupling links (7). In the low effect position the cut-off final stage module outlets function as reflectors with small reflection losses for the signals fed via the by-pass links. The two reflected signals are summed at the hybrid circuit outlet port. The gain level changeover coupling can be incorporated in an amplifier chain providing high gain with four final stage modules. |
