SHF BERT & DAC for NRZ, PAM4 and Arbitrary Waveform Generation

Transcription

1 SHF BERT & DAC for NRZ, PAM4 and Arbitrary Waveform Generation Content SHF s one for all System 2 (a) 64 or 120 Gbps binary NRZ BERT 2 (b) 60 GSymbols/s AWG 3 (c) 60 GBaud PAM4 Generator and Analyzer (PAM4-BERT) 5 Compact BERT Series 7 Optical Transmission 8 SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 1/8

2 SHF s one for all System SHF has always been pioneering the market for high speed bit pattern generators (BPGs or PPGs) and error analyzers (EAs). Now, with PAM4 being the main stream of interest for the optical and data communication research communities, SHF is continuing to push the limits by releasing BPG and EA instruments specifically designed to be used as a (a) 64 or 120 Gbps binary NRZ Bit Error Tester (BERT) or a (b) 60 GSymbols/s Arbitrary Waveform Generator (AWG) or a (c) 60 GBaud PAM4 Generator and Analyzer (PAM4-BERT). (a) 64 or 120 Gbps binary NRZ BERT The key instruments for very high speed BER testing, the SHF A / A Bit Pattern Generator (BPG) and the SHF A Error Analyzer (EA), can be configured in a variety of different channel configurations with a maximum capacity of 512 Gbps per instrument. Available for SHF A BPG & SHF A EA Aggregated Data Rate No. of 64 Gbps Channels No. of 33 Gbps Channels Available for SHF A BPG Key Features SHF BPG All channels are independent (i.e. programmable as it would virtually be a single BPG) Synchronized channels for phase and bit alignment (inter-channel bit-delay or skew can be set individually) Optional 2 V output amplitude (option HV) Extensive user pattern memory per channel in addition to the ITU / CCITT PRBS patterns Automation with external software possible (e.g. LabView, VEE, C or Python) Up to 120 Gbps with the remote head Multiplexer (MUX) SHF C603 A High quality output waveforms: Gbps 2 64 Gbps (Option HV) 120 Gbps Key Features SHF EA Individual auto search of optimum sampling point for each channel Quick and powerful measurement routines e.g. for auto-search, Q-factor, jitter, eye contour Up to 120 Gbps with the remote head Demultiplexer (DeMux) SHF C623 A SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 2/8

3 (b) 60 GSymbols/s AWG Combining a BPG with one of SHF s digital to analog converters (DACs) turns the system into a multi-channel and multilevel source. With our SHF 12104/5 A BPGs one has full control of the patterns into the DAC (due to the huge memory and the channel synchronization). Therefore, our BPG-DAC combination is a full blown remote head non-interleaved 60 GBaud Arbitrary Waveform Generator (AWG). SHF A BPG with remote head DAC modules Key Features Remote Head AWG Sample rate = output baud rate 8 GSa waveform memory (in case a SHF A is used); 1 GSa waveform memory (in case a SHF A is used) Remote head to preserve signal integrity close to the DUT Speed, vertical resolution and output power depending on the used SHF DACs: SHF DAC Max. Baud Rate Max. Vertical Resolution Max. Output full scale SHF 611 D 32 GBaud 3 bit (8 level) 0.8 V (se) 1.6 V (diff.) SHF 612 A 32 GBaud 4 bit (16 level) 0.65 V (se) 1.3 V (diff.) SHF 613 A 60 GBaud 3 bit (8 level) 0.65 V (se) 1.3 V (diff.) SHF 614 B 60 GBaud 6 bit (64 level) 1.4 V (se) 2.8 V (diff.) SHF 615 B 60 GBaud 3 bit (8 level) 2.4 V (se) 4.8 V (diff.) Typical Performance Remote Head AWG (BPG + DAC) 60 GBaud 60 GBaud Arbitrary Signal w. 60 GSa/s Unequal PAM Odd PAM (here PAM-5) PAM w. Pre-Emphasis SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 3/8

4 Channel Count Expanding the BPG s capabilities with one of the remote heads increases the speed or the number of levels. The resulting maximum channel count from the remote heads are shown below (mixed configurations would also be possible). Remote Head 2-Bit DAC 4-Level, i.e. up to 120 Gbps per channel 3- Bit DAC 8-Level, i.e. up to 180 Gbps per channel 4- Bit DAC 16-Level, i.e. up to 240 Gbps per channel 5- Bit DAC 32-Level, i.e. up to 300 Gbps per channel 6-Bit DAC 64-Level, i.e. up to 360 Gbps per channel Software package with AWG features BPG Configuration Dual 64 Quad 64 Hex 64 Oct Ideal to generate DP- 16QAM by driving an IQ modulator with 4 uncorrelated PAM-4 signals. Now, as the SHF A provides 6 or 8 channels, the full resolution of the 6-Bit DAC can be accessed at 60G. A SHF BPG and a SHF DAC are not just two discrete modules connected together. The new complementary software package, the SHF Control Center (SCC), creates the patterns for any signal trace. As for a conventional AWG, there are various options to create the waveform: Load it from a file Select from our library & change the parameters (a PAM4 example is shown below) Use the graphical sequence editor Program your waveform in our editor (Python based programming) Parameters, like the amplitude of the individual levels, the pre-emphasis etc. can be adjusted. DAC GUI of the SCC with the PAM4 library loaded The SCC just needs to know which BPG output is connected to which DAC input and an AWG is created. SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 4/8

5 (c) 60 GBaud PAM4 Generator and Analyzer (PAM4-BERT) PAM4 Generator For binary data a BPG has obvious advantages over an AWG as the bit/baud rate always equals the sample rate (no fractional oversampling) and as logical pattern generation techniques can be applied without utilizing a rather slow and small memory. In first place one may think that these advantages do only apply to a pure BPG and not to an AWG based on a BPG/DAC architecture. For most microwave signals this is correct, however, for data signals the coding can be done in the BPG hardware, thus the user memory is not used and above advantages do still apply for the signals from the DAC. Most prominently this applies to PAM signals. Even the individual eye heights or pre-emphasis can be achieved and adjusted as outlined above for a AWG but on the fly without waiting for the memory to be loaded and by still transmitting very long patterns (e.g. PRBS or PRBS31Q). No issues with long patterns (e.g. PRBS ) as the pre-coding is done in hardware! Individual eye heights can be set without utilizing the memory. Pre-Emphasis (FIR Filter) can be set without utilizing the memory. BPG GUI of the SCC for the logical PAM signal generation SHF s active DAC approach is more versatile, robust and supports more levels compared to simple passive combining. Further, it is faster than any other AWG instrument as it samples only one single time per each bit. Thus the baud rate of the resulting PAM signal is as fast as the sample rate of the system. No other AWG can create 60 GBaud PAM signals of equal signal quality. The speed advantage of the SHF system can be seen most prominently at the output signal of the SHF 616 A PAM4-MUX which supports data rates up to 112 GBaud (224 Gbps). 100 GBaud (200 Gbps) from a SHF 616 A PAM4-MUX SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 5/8

6 PAM4 Analyzer The SHF A Error Analyzer (EA) introduced above is capable not only to perform BER measurements at binary but also at PAM4 signals via the 3-pass approach. With this approach, the instrument is performing an auto-search to determine the optimum threshold values of the three individual PAM4 eyes, then successively samples all three eye openings of the 4-level signal, one at a time, and measures the three individual bit error rates. After completion of this 3-pass measurement the software calculates the total bit error ratio (BER). BCC SHF A EA GUI, showing the eye contours and error rates of a 53 GBaud PAM4 signal The SHF A Error Analyzer as a single instrument is capable to perform this measurement for PAM4 signals up to 32 GBaud. Extended with the SHF A PAM4 Sampler, the upper baud rate limit is raised to 58 GBaud (116 Gbps). The SHF A PAM4 Sampler In the PAM4 Sampler GUI, the built-in eye scan function has the capability to visualize an eye pattern of the input PAM4 signal, as well as executing a fast auto-search to determine the threshold values and delay of the input signal. BCC SHF A PAM Sampler GUI, showing the eye scan of a 53 GBaud PAM4 signal SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 6/8

7 32 GBaud PAM4 60 Gbps binary 32 Gbps binary Compact BERT Series The compact BPG series is SHF s approach of delivering a high performance signal generation solution to the cost-sensitive datacom industry. The minimal power consumption and the light weight make it perfectly suited for on-wafer tests. To date, the SHF A offered the lowest cost per bit rate of all bit pattern generators. Its successor, the SHF B, is now even offering pattern-synchronized channels to enable the generation of true PRBS at even higher speeds via a multiplexer or a DAC. Incorporating such a multiplexer or DAC in the BPG instrument results in our all new SHF B and SHF A, respectively. SHF B SHF B SHF A 2 differential 2 single-ended 2 single-ended differential differential Key Features Compact BERT Series Gap-free operation from 5 Gbps (GBaud) to the upper data & baud rate limit 4-Tap-FIR for pre-emphasis and skew control over two UI for 32 Gbps NRZ outputs PRBS 2 7-1, , , , Various clock and trigger outputs SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 7/8

8 Optical Transmission Our optical transmitters allow the generation of optical signals of up to 264 Gbps. In addition to the well-known ASK format (also known as OOK), we also offer instruments for the generation of PAM, DPSK, DQPSK, DP-QPSK and QAM signals. SHF C Up to 44 Gbps NRZ, 32 GBaud (64 Gbps) PAM & 1550 nm (O- and C- bands) SHF C Up to 56 Gbps NRZ, 40 GBaud (80 Gbps) PAM nm (C- band) SHF A Up to 56 Gbps NRZ, 56 GBaud (112 Gbps) PAM & 1550 nm (O- and C- bands) SHF D Up to 32 GBaud (64 Gbps) QPSK, 32 GBaud (128 Gbps) QAM 1550 nm (C- band) SHF B Up to 33 GBaud (132 Gbps) DP-QPSK, 33 GBaud (264 Gbps) DP- QAM 1550 nm (C- band) To perform reliable, repeatable long term measurements, all optical transmitters feature an automatic bias control for all built-in optical modulators to track the modulator optimum DC bias. This and the outstanding signal quality render SHF transmitters to be the reference signal source for many research facilities and industry partners. SHF B to create single or dual polarization QPSK or QAM SHF reserves the right to change specifications and design without notice SHF BERT V019 June, 2018 Page 8/8