microstrip antenna design guidelines
1 Choose your antenna substrate, normal PCB material will be fine for frequencies below 1 GHz.
2 Design the antenna using experiment 2 or some other method.
3 Once you are happy draw up the artwork of the antenna on Protel or another program, which will print out the design in a 1:1 scale.
4 Print the design on transparent film (ask lab technicians and lecturers for details.)
5 Expose the design under UV light with the design on the film covering the substrate area you want the design to appear on.
6 Create a developer solution to remove the photoresist.
7 Place the antenna in the etching tank to remove the unwanted copper.
8 Once the antenna is finished then you can solder a connector on the feed line and then test it.
Antenna Testing
Here is a description of some basic methods, which are used to test the various microstrip antenna parameters.
Impedance measurements
Network Analyser
Input Impedance characteristics
Smith Chart plot analysis
SWR analysis
s12, s21 transmission characteristics
Radiation measurements
Preferably done in an anechoic chamber
Can use a simple set up with the following equipment:
Signal generator (transmitter)
Spectrum analyser (receiver)
Set up which will rotate the antenna 360o.
Alternatively use a network analyser and connect the transmitting antenna to one port (s11) and receiving antenna to the output port (s22).
By moving the antenna at different angles and taking power measurements using the receiver (spectrum analyser or network analyser), a plot of the radiation pattern can be obtained. Cross-polarisation measurements can be made by changing the field plane of the receiving antenna.