The HDIQ IQ Modulator converts signals from external intermediate-frequency sources, such as arbitrary waveform generators, to the microwave frequency range using an external local oscillator (LO) signal. The HDIQ contains 4 IQ modulation units: each of them can be independently switched between 3 modes.
In calibration mode, the radio-frequency (RF) signal of the internal mixer is sent to the calibration (Calib.) port, from where it can be routed to a measurement instrument for mixer calibration. In RF mode, the RF signal of the mixer is sent to the experiment (Exp.) port, which is useful to apply modulated and pulsed signals to a device under test. In LO mode, the LO input signal is routed directly to the Exp. port: this is useful for generating continuous-wave signals with a large dynamic range in frequency and amplitude. All switches are controllable by TTL input signals. Thanks to the floating RF circuit design, there are no extra ground loops. For LO leakage minimization and sideband suppression, Python programming for automated calibration of IQ mixers is supported.