| 摘要 |
<p>The invention relates to an arrangement for bypassing a low noise amplifier unit in the front stage of a radio receiver, especially intended for the base stations of mobile communication networks. The front stage includes, in succession, a divider (420), an amplifier unit (430) comprising two parallel, low noise amplifier branches, and a first combiner (450). The by-pass arrangement includes a second combiner (443), by which the halves (E<SUB>11</SUB>, E<SUB>12</SUB>) of the received signal are combined immediately after the divider before the amplification. A change-over switch (SW) is then used to select either the signal that has propagated through the amplifier unit and then combined (G-?<SUB>1</SUB>) or the signal (E<SUB>1</SUB>') that has been directly combined as the output signal of the front stage. Due to the invention, the noise figure of the front stage is improved and the integration of its structure is facilitated.</p> |
