My requirement is to design a Direct QPSK modulator at 8.5 GHz for 10MBPS data rates. I have come across HMC1056LP4BE which is an IQ modulator form Analog Device.
1) Can this be used as Direct QPSK Modulator by feeding my LO output(unmodulated) of 8.5 GHz to its input signal port and get QPSK modulated RF output signal at its output port as shown below?
1.) If yes, then the output from the double balanced mixer's should be fed into in-phase power combiner, which is not represented here in this block diagram. The output of the mixers is simply merging at the port no 3 via a capacitor.
2.) If not, do you have direct QPSK modulator at X-Band?
Request you to kindly provide your suggestions.