Likely not. The antenna on most laptop tend to be fairly well engineered and being behind the screen tends to be optimum placement.
You only hope would be a device that has directional antenna. It depends how big a device you want to carry around even the smallest devices are at least half the size of most laptops.
What is strange is the cheapest devices are actually outdoor bridge. You can get directional antenna for wireless cards but they don't save any money.
You could look at something like unbiquti nanostation m2 or engenious ens200 are in the $50 range. Still this mean caring along another piece of equipment and it may not help in all situations.