I have used and highly recommend the external antennas from Alfa.  You can find a variety of them on Amazon here.  I have used mine quite often while traveling to connect to the free wifi across the street from the hotel (when mine charged), the Starbucks two doors down while I'm eating somewhere w/o wifi, free wifi while I'm parked in a parking lot while working on the road.

Alfa external antennas are very highly regarded and recommended between techies too.

I use to be in IT, so sorry for all the questions.   What type of WiFi card do you have?  What bands does it support.  B, G, N, AC.  What fequency does it support, 2.4 Ghz and or 5 Ghz?   2.4 Ghz reaches further but is a more congested frequency, best to use 5 Ghz, les range though. Does reception loss happen at all hotspots or just certain ones?  How about when your closer to a hotspot?  Do you know if the hotspots limit speeds on their end?

I know of nothing that boosts the reception side.  Other things could affect wireless signal like a high energy motor or compressor that kicks on.  Maybe someone turned on the microwave. 

Most laptops that have a WiFi card have two wired connections that connect to a hidden wire behind or along the sides of the screen.  The wires could have gotten damaged or disconnected.  Could also be the wireless card itself.  Maybe it got fried.  They are fairly easy to replace.  Maybe try swapping it out with a new one.  You could also disable the internal wireless card and purchase a USB wireless dongle.  See if that fixes it.

Parked and Reading. 

I've had no need for this. 

I have one that I use with one of my laptops when working at one of my volunteer places where the wifi from the library across the street is a bit weak.

They do help and they are not very expensive, check out walmart and see what they have available.

David,

I wish you had asked this question when we had no internet do to fire and floods and lived on hot spots.  A big Thank you to Ryan Huggins - Thousand Oaks, CA  for the answer.  A

Mac or PC?

That's like an ancient kind of thing that I used to use when phones were not 1/2 of what they are now. Eons ago I used to get my internet thru that little antennea in the USB. Don't even know if they have that stuff anymore.

I have a micro cell tower from AT&T and it works amazing.

I have used NetGear's plug-ins in my 'wide' home, David Martin - and it has worked well.

I can honestly say I've never heard of such an animal! Anxious to see what others have to say, David!

I have no idea. I have had wi-fi cards get weak and replacing them gave me the boost I needed.

I never ever use unsecured wifi so I have no need.  I use my phone as a hot spot and my speeds are exceptional.

beyond my paygrade....

 See the answer from Shawn and Angela Miller 

Blog about your selection.

Have not used any, and hot spots are usually good.   Reading comments.

Looking for the same recommendations!

No idea.

I am looking for the answwer

I've not needed this in my house so have never looked for it. Will read responses with interest.