Diplexers are three-port frequency
selective devices that may be used as a separator or a combiner of
signals. The low-high diplexers manufactured by Allen Avionics consist
of two filters sharing a common port. The common port and the output
of the two filters (low and high) or (RX and TX) form the three
terminals of the diplexer. Signals applied to the common port are
separated in accordance with the passband frequencies of the filters.
offers 6 different shape factors for
the contiguous Low-High Diplexer series. For each shape factor a
simple multiplication from the data listed in the table to the right
will give you the frequencies for the 20dB & 40Db attenuation points.
There are many choices for the custom packaging of diplexers which,
includes surface mount, flat pack, through hole or in metal cases with
connectors as listed in the table below. BNC or SMA connectors are