Multiplexing device for grouping two frequency bands

A multiplexing device for multiplexing two frequency bands B1, B2, in which the frequencies of B1 are lower than the frequencies of B2, said device comprising:

• an input adapted to be coupled to an antenna which receives said frequency bands B1 and B2,
• a first polarization duplexer connected to said input and including a common guide for passing bands B1 and B2, said common guide having two successive guide sections, each guide section having a single coupling hole in which is placed at least one resonator tuned to a frequency of band B2, the coupling holes of the two guide sections being rotated with respect to one another by 90.degree. about the common guide and designated as first and second coupling holes, said first duplexer further including two rectangular guides, one leading to said first coupling hole and the other leading to said second coupling hole, each rectangular guide having two parallel short sides and two parallel long sides;
• a second polarization duplexer relating to band B2 and connected to said first polarization duplexer;
• and
• first and second filters, said first filter being placed between said first coupling hole and said second coupling hole and constituting a short-circuit for the waves of band B1 which have a first polarization, and said second filter being placed between said second coupling hole and said second duplexer and constituting a short-circuit for the waves of band B1 which have a second polarization orthogonal to the first polarization.