Application Notes / Tutorial Notes

Additional information on the mode of operation of SHF’s products:

Application Notes
Discrete Linear Equalization Filters for Cable Loss Mitigation
The purpose of this note is to highlight how a simple passive impedance-matched equalization filter can effectively compensate for a significant degree of impairment caused by a piece of coaxial cable of various lengths.
Creating Complex Jittered Test Patterns
This note describes the generation of stressed signals with the SHF instruments.
611 C
The SHF 611 C is a 3-Bit Digital to Analog Converter modules. This application note is intended to help the operator to easily find and set up the optimum bias settings.
611 A / B
The SHF 611 A and the SHF 611 B are a 3-Bit Digital to Analog Converter modules. This application note is intended to help the operator to easily find and set up the optimum bias settings.
Multi-Channel BPG SHF 12103/4 A
The objective of this note is to provide a reference to illustrate how to make the best use of the truly synchronous features, dual bit rate bands, and multi-channel nature of SHF 12103A and 12104A BPGs. Hardware implementation examples are given towards the realization of many advanced system experiments.
Jitter Injection using the Multi- Channel BPG
This note presents the setup to allow injection of jitter using a SHF Bit Pattern Generator. It demonstrates that SHF BPG’s are jitter transparent, i.e. it correctly transfer jitter from the clock to the data output signal. This enables jitter tolerance tests as required by many telecommunication standards such as 100G Ethernet and 40 GBit/s OTN.
Multi-Level Signal Generation using the Multi-Channel SHF 12103A
The objective of this note is to provide a simple guide on how to make the best use of the SHF 12103 A Quad-32, 4-channel 32 Gbps BPG, as a multi-bit data source, to realise 4-level electrical signals when used in conjunction with an external broadband power combiner.
Skew Control
This application note describes how the alignment of the output signals from the Pattern Generator SHF 12103A could be adjusted greatly over many bit periods (integer bit delay) and fine-tuned within tenth of a picoseconds (skew control).
DQPSK – Bit Error Test Solution
Provides a general overview of the optical DQPSK, the generic structure of the SHF DQPSK optical TX and RX modules and the application in conjunction with SHF’s 50 Gbps BERT System
Jitter Analysis using SHF 10000 Series BERT Equipment
A short description of jitter and a tour of the SHF software used for the measurements. Includes an outline of the theory involved.
Operation of the SHF 46100 A E/O Converter
Describes the principle of operation and offers some hints on how to get the best out of the module.
Impact of Bias Tees on Communication Signals
Contains data and advice on some issues which should be considered when selecting a bias tee.
Using SHF BERT Systems in Fiber Loop Experiments
Describes the use of a Brimrose Controller in recirculating fiber loop experiments in conjunction with SHF equipment and special extras.
Eye Length Adjustment Application Note
Describes the feature on SHF multiplexers and pattern generators for adjusting the eye length.
Upgrading 12 Gbps BERT systems to 50 Gbps
There are several ways of upgrading to 50 Gbps depending on cost and functionality. This application note gives an overview of the different methods.
Effect of Bandwidth of Measurement System on RZ Signals
Electrical RZ signals demand measurement instruments with very high bandwidth for correct measurement. This application note shows some typical measurement setups and the results that can be expected from them.
Cause of Unequal Error Rates in EA Subchannels
Gives details about how the SHF EA 44 detects errors, and explains why this can lead to channel-dependent errors if the instrument is not set up correctly. The solution is straightforward once the mode of operation is understood.


Helpful background theory and information.

Tutorial Notes
Tutorial Note 1 – Important RF and MW Parameters for Broadband Communication
Phase response, group delay, S-parameters, VSWR, noise figure.
Tutorial Note 2 – Microwave Connectors
Types of connectors, compatibility, specifications, care and cleaning.
Tutorial Note 3 – Broadband Communication Signals
Transmission bandwidth, PRBS signals, correct multiplexing and demultiplexing, eye diagrams, Q-factor, jitter, bit error rate, error analyzers.
Tutorial Note 4 – Basics of Optical Communication
Background information about optical detection, polarisation, chirp, dispersion and non-linear effects.
Tutorial Note 5 – Modulation Schemes
EA and LiNb modulators, ASK, BPSK and DPSK modulation.