While I was designing and simulating the antenna, I found that the scattering parameters (S11) were giving unexpected results and not showing the correct frequency values.
After consulting with others who had used the software before I learned that, because the wavelength is so large at the frequency we are using - almost 15 metres, the antenna components are too electrically small to be simulated by the software.
I have decided that it is important to verify the concept of meanderline antennas however a higher frequency needs to be used.
In the initial project plan there was scope to investigate pulsars using the antenna and, as these work at much higher frequencies, I have decided that my concept antenna will focus on observing pulsars. I will therefore continue to design an antenna using the CST Microwave Studio software but aim for 400MHz - a common frequency for pulsars - in order to prove the concept.
Sunday, 25 November 2012
Thursday, 15 November 2012
Designing a New Antenna
As I mentioned in the previous post, I will be using the concept of Meanderline antennas to try and optimise the design for the antenna. The antenna needs to be designed first, and then simulated in the design software before it can be manufactured and tested.
I have started using the software CST Microwave studio and have worked through an antenna design tutorial in order to learn how the software works and its capabilities. The design itself will just be meandering the copper tracks until the antenna is the correct length for the frequency required - in this case 20.1 MHz.
The design will also incorporate a ground plane underneath to prevent the antenna receiving signals reflected from the roof of the department.
While I am designing I will be simulating the design to check that the Scattering Parameters (s-parameters) show the antenna working at the frequency we expect it to. The radiation patterns will also be checked to ensure that the design is initially omnidirectional and that the ground plane is preventing signals from below reach the antenna.
I have started using the software CST Microwave studio and have worked through an antenna design tutorial in order to learn how the software works and its capabilities. The design itself will just be meandering the copper tracks until the antenna is the correct length for the frequency required - in this case 20.1 MHz.
The design will also incorporate a ground plane underneath to prevent the antenna receiving signals reflected from the roof of the department.
While I am designing I will be simulating the design to check that the Scattering Parameters (s-parameters) show the antenna working at the frequency we expect it to. The radiation patterns will also be checked to ensure that the design is initially omnidirectional and that the ground plane is preventing signals from below reach the antenna.
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