That last few weeks have been insanely busy for me.
First, I sold all of my furniture and said goodbye to my former apartment in Kiel, since I'll be leaving for Montreal on Tuesday (yaaay!!). Since then, I've been couch-surfing at a friend's apartment down the street. Moving out was a huge undertaking, and I'm quite relieved that its over. There's something extremely liberating in a sort of Zen-Buddhist way about living out of a backpack.
Also, I've been putting in crazy amounts of overtime on my thesis project, which is coming along spectacularly. I've been meaning to write a blog post about it, without giving away too many things prematurely (call me superstitious, but I feel it could jinx me in the end). All I can really say at the moment, is that it's really pushing the physical limits, and that the antenna actually depends on materials being in the near-field. I will allow myself to expand on this point alone for clarification. For most people with any background in physics or engineering, it's common knowledge that EM wave propagation slows down in matter. The wave propagation velocity is equal to the speed of light in free space, but in any material with a relative permittivity greater than 1, the propagation velocity decreases. However, since the measure of time remains constant, the frequency remains constant. Subsequently, in order to maintain equality, the wavelength (L) shrinks according to the equation L = cr / f. A really fantastic consequence of this (antennas not-in-free-space), is that an antenna tuned to a specific frequency surrounded by a given material is often a significant fraction smaller than the equivalent antenna in free space. The resonance remains the same regardless of the angle of incidence (although directional gain is clearly affected). Half-space (or really multi-space) simulations of my antenna design (thus far) have allowed me to reduce the antenna size by a factor greater than 2! Without this near-field effect, it would literally be impossible to create an antenna that resonated in my required frequency range (the lower frequency bound being inversely proportional to the antenna dimensions - the limiting factor). This last week, I've been working on accurate 3D modelling of a planar antenna projected onto the surface of a half-ellipsoid (in order to approximate the inner curvature of a prosthetic eye), which will be the final addition to my simulation. I will then need to do some fine-tuning of the antenna dimensions (this will likely be some sort of constrained numerical optimization, perhaps MMSE), and finally I'll be able to build a physical prototype. Its safe to say though, that it has been far from an easy task. Limitations of our FDTD software and API did pose a major hurdle at one point. I've been doing a lot of the 3D modelling lately in Matlab (with its severely limited Dulauney triangulation capabilities) but I will eventually (or rather in the next week or two) have to write a Dulauney triangulation module in pure Python to interface with the FDTD API. I'm not a huge fan of Python, but I do what I must. In short, I really think that this antenna will be the first of its kind. I can't imagine that anyone has ever created such a specific design, just as the Eyeborg project is equally the first of its kind. The remaining things will be a bit of an exercise in reverse engineering, since I received absolutely zero assistance (so far) from WUSB transceiver chip vendors. I'll also need to improve the state of the Linux WUSB stack. Hopefully when chip vendors see a demonstrated prototype they'll be more inclined to cooperate with us on the Eyeborg design.
My GSOC project was on a bit of a hold this week, since it was my last week in Germany and I needed to focus on thesis work before my flight on the 15th. However, tonight I should be able to accomplish the tasks that I set for myself last monday. Keep an eye on my GSOC blog tomorrow for my weekly report.
Lastly, I leave you with a token of motivational music that should indicate my my overly-caffeinated state of late. Major thanks go to the countries of Ethiopia (for producing such great coffee), and Austria (for inventing RedBull).