| 摘要 |
<p>An RF switch circuit includes a waveguide transmission line (19) having an input port (18a), an output port (18b), a first wall having a first cavity disposed therein and a second wall having a second cavity disposed therein with the first and second cavities being aligned along a centerline of the waveguide transmission line. An RF choke (44) provides a substantially short circuit impedance characteristic between the first cavity and the waveguide transmission line to RF signals propagating along the waveguide transmission line. An electrically conductive member (36) disposed in a first region of the second cavity has a PIN diode (38) having a first electrode disposed on a first surface of the electrically conductive member (36). An electrically conductive post (46) has a first end disposed in the first cavity and a second end disposed in the second cavity with the second end of the post electrically contacting a second electrode of the diode (38). Bias drive is applied to the upper second, end of the post (46), the electrically conductive member (36) being earthed through the body (23) of the transmission line (19). Spacer rings (40) set the diode (38) in resonant circuit. The choke (44) is also spaced (42) from the transmission line (19) to provide a quarter wavelength termination. The switch circuit is closed when the diode (38) is fully conducting, and open when the diode (38) is nonconducting. <IMAGE></p> |
