| 摘要 |
<p>A bypass device in a low noise amplifier unit for amplifying communication signals in the microwave frequency range. The device includes a printed circuit board with transmission lines (1, 2), an amplifier (A), a transmission line bypass segment (3) extending in parallel to the amplifier, and switching means for activating said bypass segment in case the amplifier becomes inoperable. The amplifier is connected between two transmission line stub segments (4, 5). The switching means include solid state components (Z1, Z2, Z3, Z4) having a controllable impedance, either very low or very high, these components being connected to ground at selected points (3a, 3b, 4a, 4b) in the bypass segment (3) and in the stub segments (4, 5) so as to activate the bypass segment when all of said solid state component are in a state of very high impedance and to effectively cut off the bypass segment when all of said solid state components are controlled to a state of very low impedance, in which case the communication signals pass through the amplifier.</p> |
