M8296A Electrical High Speed Digitizer

• Max symbol rate 74 Gbaud
• Sampling rate 83 to 92 GSa/s
• Memory depth 512 kSa
• Operating frequency range 50 kHz to 42 GHz
• Analog bandwidth, uncorrected 37 GHz (3 dB)
• 1-slot AXIe module with 4 electrical input channels

The Keysight M8296A is a four-channel, high-speed electrical digitizer module for the AXIe platform. It can synchronously sample up to four incident waveforms and is ideally suited to digitize the output signals from a dual-polarization coherent receiver. Keysight’s vector signal analyzer and optical modulation analyzer software serves as the M8296A's user interface and enables a multitude of test and measurement tasks such as spectral analysis and digital demodulation for the analysis of signal quality metrics like error-vector magnitude. Furthermore, the sampled waveform can be stored and processed with the user's own tools (e.g. using Matlab). The modular approach allows users to combine the M8296A high-speed digitizer with other modules in one mainframe such as the M8292A modular optical modulation analyzer and the M8196A 92 GSa/s arbitrary waveform generator.

Automated Integrated Coherent Receiver Testing

Integrated Coherent Receiver (ICR) modules are key components in coherent transmission systems and are more challenging to test than direct-detection receiver optical sub-assemblies (ROSAs), as the ICRs have phase-sensitive signal detection and provide four electrical outputs and two optical inputs. The test instruments used in ROSA S21 testing cannot be used in a similar way for S-parameter testing of ICRs, making S-parameter testing very challenging.

The M8296A electrical high-speed digitizer connects to the four differential outputs of an ICR and enables setting up parametric tests in very short time. In combination with two tunable lasers, a polarization synthesizer and the optionally-available ICR test software, the M8290A solution measures:

• S21 magnitude response of all detection paths
• IQ skew, XY skew
• IQ angle
• IQ and XY gain imbalance
• EVM noise floor
• Image suppression