Antenna and Microwave Laboratories
Dept. E&E Engineering, University of Stellenbosch
Issued: 1st of April 2004
Who may use the Laboratories
The Laboratories are intended for students and staff with High Frequency and Antenna orientated projects. In all cases prior permission is required.
Permission
Permission can be obtained only from the laboratory manager or your supervisor/course lecturer. They will ask you to study the laboratory rules carefully, complete a ‘Laboratory Registration Form’ and, if necessary, assign you a work bench.
Responsibility
It will be your and your supervisor/course lecturer’s duty to ensure that you are familiar with the responsible and proper use of all instruments to be used and that you have been appropriately trained. Safety of users and instruments is of prime importance!
Postgraduate users, technicians and staff are asked to use the laboratory responsibly and to set a good example for final year students. They must make acquaint themselves with the laboratory rules and implement them at all times.
Postgraduate students are authorised to enforce the rules on final year students should the need arise!!
Available Equipment
A short summary of all equipment in the laboratory is available at:
http://services.ee.sun.ac.za/hflab/equip.htm
Damage and Accident
The replacement value of our equipment in both laboratories exceeds R10 million. Damage to any instrument is both very expensive and accompanied by long repair periods. Most students and staff depend on the availability and trustworthy performance of the instruments for research, study and teaching. Damage to instruments will have disastrous consequences for students and lecturers alike.
It is of utmost importance that any damage or accident (injurious or otherwise) in the laboratory be reported to the laboratory manager immediately, to correct any resulting problems at an early stage and to keep the laboratory safe and in excellent working condition.
Anybody can make a mistake or accidentally damage equipment. In fairness, circumstances will be taken into account and a rather generous willingness to forgive exists. . However, malicious damage or failure to report an incident excludes any goodwill towards you. Exclusion from the laboratory could result!!
Booking of Equipment
All workstations can be booked, provided you have permission to use them. People who book the laboratory in advance have absolute priority and are entitled to ask anybody who is occupying the booked equipment to make it available immediately. Please cancel your booking if you intend not to make use of it after all. If you fail to occupy the booked analyser within 15min you lose the right to use it.
The following equipment can be booked online using Outlook’s public folders section.
· For the Agilent HP8510C and the Antenna Lab use:
Public Folders/All Public Folders/Ingenieurswese/E&E Ingenieurswese/Lokaal Besprekings/AntennaLab-8510C
· For the Agilent HP8753 in the RF Lab use:
Public Folders/All Public Folders/Ingenieurswese/E&E Ingenieurswese/Lokaal Besprekings/RF-Lab-8753
· For the Rohde & Schwarz ZVB in the RF Lab use:
Public Folders/All Public Folders/Ingenieurswese/E&E Ingenieurswese/Lokaal Besprekings/RF-Lab-ZVB
If you don’t have access to the public folder you can have reservations made by your supervisor or the laboratory manager.
For certain other instruments, i.e. signal generators, spectrum analysers and oscilloscopes, the books available in the laboratories must be used to make reservations.
All users of equipment/workstations, booked or not, are required to enter their name(s) into the appropriate equipment/workstation user register available in the respective laboratories.
Removal of Equipment
Removal of any equipment from either of the two laboratories is strictly subject to the prior written consent of the laboratory manager (i.e. write down what you wish to borrow, date your request, get it signed) and may not exceed a period of 2 days (this includes weekends, public holidays and vacation time). Such authorised removal of equipment still requires you to sign for the instrument in the sign-out book in the laboratory (on the Instrument Table). Equipment in current use can not be signed out.
Return of Equipment
All equipment should be returned to where you obtained it. Instruments generally belong on the Instrument Table. Make sure you sign it back in (in the sign-out book).
All cables and probes should be returned to their appropriate place on the cable rack. Please remove all markings and/or tape from your cables before replacing them in an orderly manner.
Visitors
Visitors are welcome in the laboratory provided they abide by the rules. They must be accompanied by at least one authorised person who takes full responsibility for the visitor(s) and who may not leave any visitor unattended.
No external persons (including visitors) are allowed to make use of either laboratory on their own. Use of the laboratory must always be arranged with the Lab manager or one of the lecturers.
Connectors Use and Care
Connectors must always be cleaned before use. Only the cleaning solutions provided (in plastic cans) should be used to clean connectors. Under no circumstances should methylated spirits or benzene or any other solution be used to clean connectors.
Every student using the lab must have had a detailed education in the proper care and use of connectors. If you have not had a connector training session, ask the Lab manager or your supervisor. No excuses will be accepted for the mistreatment of connectors.
The cleaning procedure varies for different connector types:
Clean the SMA connector:
• use a toothpick,
• apply the cleaning solution and carefully loosen all dirt in the thread
• If there is dirt on the Teflon face loosen it with a wet toothpick.
• Be careful on the Teflon face – Don’t rake it up!
• Repeat this procedure until the toothpick doesn’t show dirt.
• Use a cotton swab, apply little cleaning fluid and wipe the connector.
• Finally use air to dry the connector.
– Never shake the air can!
– Press the knob gently to ensure economical use.
– Start blowing air aside of the connector moving the flow onto it.
– Don’t blow the thread of the female connector.
Clean the 3.5 mm precision connector:
• 1use a toothpick,
• apply the cleaning solution and carefully loosen all dirt in the thread.
• Repeat this procedure until the toothpick doesn’t show dirt.
• Finally use air to dry the connector.
– Never shake the air can!
– Press the knob gently to ensure economical use.
– Start blowing air aside of the connector moving the flow onto it.
– Don’t blow the thread of the female connector.
• Never clean the centre pin of the male or female connector!
Never apply the cleaning solution directly onto a connector.
Always clean the connectors before using them.
Cleaning connectors regularly will not only make them last longer, but will also provide better results for your measurements.
Never clean the APC connectors fitted at the instruments. Lab maintenance is responsible for that!
Work-Benches, Drawers and Cabinets
Work-benches will be allocated to you in the microwave laboratory. You may leave your experimental set-ups on your assigned work-bench. Although these are work areas, they should be kept neat. Books, coats, jackets, bags and the like do not belong on them. These are to be stored elsewhere; e.g. under the bench.
After completion of your experiments you are to clean up your work area, clearing bench and the floor of solder, wires, paper and general debris.
You must properly store all equipment and materials and lock drawers and cabinets at the end of your laboratory period or when no longer in use. Equipment left out may be confiscated.
In fairness to others, you are not allowed to remove equipment connected to set-ups or remove components and tools from other’s work-benches.
Before Leaving the Laboratories
Make sure that all the equipment you used has been turned off and returned to its original location.
If you are the last person using the laboratories you must switch off the lights and the air conditioning.
The computers should be left on, but don’t forget to log off.
The network analysers are allowed to be left running if they will be used by someone else at a later stage but their display intensity has to be turned down to protect the screen from burn-in! Similarly, the HP8671B signal source may be placed into ‘stand-by’ mode. These instruments have long (hours) warm-up periods. If in doubt, please switch off.
Put all accessories back to their original locations. Cables belong on the cable shelf; smaller equipment on the shelves as marked.
General Conduct
People from different walks of life have to work together in this laboratory.
To ensure fullest use of the laboratory by everybody, the following rules apply:
· No smoking in the laboratory or on the roof, as in the entire building.
· Cables and other equipment that are not currently in use have to be returned to their proper places and not thrown or placed aside ‘somewhere’.
· Broken cables should be reported to the laboratory manager.
· Do not leave the door open.
· No unauthorised experiments
Food in the Laboratory
No eating, drinking, smoking, chewing gum, use of inhalators or other consumption is allowed in the laboratory. Food for consumption must not be kept in the laboratory. No food or beverages may be prepared inside or brought into the laboratory.
Equipment Safety
Correct precautionary measures can secure the safety of instruments and ensure worry-free measuring for all parties concerned. The department has only limited funds available and would prefer to spend them on upgrading of laboratory facilities rather than repair of equipment and instruments. The following items should therefore be considered:
· Damaged or broken equipment is to be reported immediately to the laboratory manager.
· You are not allowed to repair any equipment.
· You are not allowed to open any equipment without prior written permission from the laboratory manager.
· Do not operate equipment you may think you know how to use but don’t! Ask your supervisor or the laboratory manager.
· Equipment must be set up, operated and maintained according to the manufacturer’s instructions.
· Do not inhibit the ventilation of equipment by covering it.
· Make absolutely sure of the maximum power levels for the specific instrument and take precautions that this level is never exceeded. Take special care when active circuits are connected to the network- and spectrum analysers and be very certain that measures are taken to protect the instrument against unwanted power.
· Always make sure that the DC block is present when measuring with the spectrum analyser and do not remove it unless you are very sure of what you are doing. Let your study leader check your measurement set-up before it is powered up.
· Electrically earth yourself before touching the ports of the network analyser and make sure that all cables are statically discharged before they are connected to the network analyser.
General causes of damage
· Power cables that are not earthed – MAKE SURE THAT THE EARTH PIN OF EACH PLUG IS CONNECTED TO THE CABLE – BE AWARE OF CABLES FROM OTHER LABS!!
· DC voltages and currents on active circuits – Use capacitive decoupling and make sure that coupling capacitors are discharged and power supplies switched off before the circuit is connected.
· Static charges on long cables – ALWAYS discharge cables before they are connected.
· High power levels – Be very careful with amplifiers and oscillators. Use attenuators.
· Mechanical damage to connectors – Connectors and cables are VERY expensive and sensitive. Handle them with great care and they will last and be used by everyone. Read the paragraph about connectors very carefully and IMPLEMENT IT!!!
Anechoic Chamber
The anechoic chamber is very prone to electrostatic charging. This can be fatal for the network analyser. The cables, antennas and people inside the chamber become charged very easily. When entering the chamber therefore, all cables must be disconnected from the network analyser. When you emerge from the chamber you should first discharge yourself, and then discharge the cables that are to be connected to the network analyser. The anti-static grounding strap should be worn at all times and be connected to the common ground plane. Cables can be discharged by connecting a load or a short circuit to them.
The absorbers inside the chamber are expensive and it is important that their tips remain sharp. The absorbing cones should therefore never be stacked on top of each other or anything else put on the tips of the cones. Two absorbing blocks should not even be stacked on each other with the top one upside down, since that will also damage the tips. If any of the blocks are removed form the chamber, they should be packed neatly outside in the antenna lab and returned when the measurement is finished.
General Safety
All general safety rules applicable to the University of Stellenbosch can be found at: http://www.acts.co.za/ohs/index.htm and must be adhered to.
In addition to these the following also should be adhered to:
· No chemicals, biological materials and cultures, radioactive materials, isotopes, explosives, flammables, or guns may be brought into the laboratory. If such are required for official experiments, a written letter of permission, approved by the laboratory manager and the head of the department is required. Training in handling, storage and disposal of such materials, as well as safety procedures, must be ensured and proven before permission is granted. .
· Cryogenic liquids have to be in proper storage containers for transport and storage, and are not to be left unattended. Before they are used in the laboratory:
o Those using them must be trained in their use.
o The laboratory manager needs to be informed of their use
o Appropriate warning signs, as well as labels describing the contents, are required on all storage containers.
· No open flames in the laboratory
· Approved warning signs should be displayed in areas of danger
· You should obey warning signs and signals
· You must know where fire extinguishers are and be familiar with their proper use.
· In the event of a fire, follow fire regulations.