Integrated orthogonal mode transducer/filter design for microwave frequency-domain

摘要

A printed circuit board (PCB) transceiver I/O filter design which provides both polarization and isolation filtering includes a receive probe positioned in a first orientation in an opening of the PCB which has a feed waveguide attached to it on a first side of the PCB. Receive signals propagate into the feed waveguide and excite the probe causing the receive probe to couple the received signals to receive circuitry. The transceiver design further includes an enclosed waveguide structure attached to the PCB having a first end positioned over the PCB opening and a second end positioned over a transmit probe which is positioned in a second orientation orthogonal to the receive probe. The transmit probe is excited by transmit circuitry and couples signals into the waveguide structure through the PCB opening and out the feed waveguide. Since the transmit probe is orthogonally oriented with respect to the receive probe, transmit signals emitted by the transmit probe are polarized orthogonally with respect to the receive signals thereby providing polarization isolation of the receive and transmit signals in the feed waveguide and the PCB opening area. The enclosed waveguide can be constructed to have an associated cut-off frequency that is greater than the maximum frequency of the receive signals thereby providing isolation filtering in the enclosed waveguide of signals in the receive signal frequency range. Alternatively, the waveguide structure can be designed as a bandpass filter to provide isolation filtering between receive and transmit signals.