Could some electronics guru here point me to an equivalent circuit model of a microstrip antenna, specifically one that is related to the physical parameters of the dipole. I have one such equivalent circuit model that can be applied to dipole antenna made of wires with finite diameter, but I am more interested in the planar microstrip variety. All hints, suggestons are welcome. Thanks in advance.
Depends what you are trying to model. From a systems point of view it models as a voltage source with a source resistance. There are 25 different way to model this from easy peasy to using an electromagnetic simulator. What are you triny to model?
If you put a ground plane under the dipole, as in a microstrip PCB, it's not going to radiate very well. The transmission line feeding the dipole can be a microstrip, but not the antenna itself. Look at the example antennas in AN058 and DN031 mentioned below. If you look at the photos, there's no ground plane under the antenna section:
Also, antenna models are usually NEC2 or NEC4 models. The lumped element model can be extracted from the Smith Chart or reactance graph produced by the antenna modeling program. I'm partial to 4NEC2 which unfortunately doesn't do PCB antennas very well. Unless the dipole is a fairly trivial construct, the equivalent lumped elements are not likely to be very simple, especially if your model includes reflections, absorptions, and added capacitance from nearby objects.
TI AN058 amd DN031 have some good detail on small PCB antennas. No clue if this will help, but it's worth reading.
Hint: Add some numbers to your question and you'll probably receive better answers.
Jeff Liebermann firstname.lastname@example.org
150 Felker St #D http://www.LearnByDestroying.com
I have created SPICE netlists for equivalent lumped element models of patch entenna, that can be used to estimate frequency response, reflection coefficient, VSWR etc., I aim to do the same for planar microstrip antennas.