Different design topologies for implementing QPSK modulator

[fahsa]

microwave QPSK modulator

what are the different design topologies for implementing QPSK modulator at microwave frequencies. I have come to know only one named 'reflection topology'.

 

[flatulent]

other way

Another way is to generate it at a lower frequency with ordinary mixers and hetrodyne the result to your final frequency. This is easy to do on half duplex links as you can use the same local oscillator as used in the receiver.