Hi to all,
I want to design a microstrip antenna having high feed point impedance (or high inpput impedance)... I know that I could get something in the order of 200-300 ohm.. I basically want to use the antenna in a rectenna and I want high voltage output from antenna ( current in order of 2-3 uA would do!!!)... But voltage should in order of 1 V.. Could I get a small sized microstrip antenna which has a feed impedance of 1 kohm (I have never come across such a thing...) Otherwise I figure I would just need to use a array of antennas..
Also could anyone give calculations for size of microstrip antenna at 2.4 GHz??
Thanking all in advance..
Regards..
Pheonix..
Printed fractal antenna would give impedance as high as KΩ. You can go for Sierpinski fractals. The microstrip design for 2.4GHz would be 5cmx5cm approx. Even normal rectangular microstrips would fetch you high impedance depending on the feed location.
For a full efficient patch antenna, consider 1/2 wavelenght. You can make it shorter by adding an irregularity inside the dielectric: for example a short (electric wall) between the the radiating element and the ground.
The design procedure for the antenna is given in Balanis. But you will have to tweak the design a little to meet your requirements. None the less calcultaions in Balanis can give you a starting point.
Abhishek
I designed a folded patch antenna.... Its about (lambda)/16 sized antenna...
I did NOT get any method to increase the antenna impedane... So the output voltage was not that high... As a result, I used a array of such antennas..
I used Ie3D to simulate the folded patch antenna (its vertical folding) ... Iisa great simulator...
any thing else that you want to ask?
You can use inset fed microstrip antenna. The length of the inset can determine the inouyt impedance of the antenna, it can be tuned around 500 ohm, but I'm not sure about 1kohm.