Sum rectpuls(x-j,w) FAST

Hello dear experts, I have been following this community quite a while and was always very lucky to find smart solutions here to the problems I couldnt find myself. Lately though, I am struggling very hard with the following problem:

I need a fast solution which allows me to put together a train of rectangular pulses like so:

spectrum = [sum over i from 1 100] j*rectpuls(-100:0.1:100-0.5*i,2*0.02*i),

hence a train where each pulse differs in a welldefined manner in height, width and location. Neither could I find a pulstran solution nor a fast bsxfun solution. Of course I could find easily a for loop but for later application, this one is way too slow for me. Help is greatly appreciated.

With respect, Martin