At HOPE I got to look at a cell-phone jammer owned by a friend. This one is interesting because 1) its extremely well designed 2) it’s very small and 3) it actually has a PLL instead of just being open-loop controlled. The entire package fits into a pack of cigarettes.
(For more disassembly photos & comments…)
The design is made of 3 PCBs bolted together.
The silkscreened cover is also the microstripline antenna for the two VCOs
The battery is a large LiIon, there’s a protection circuit that looks like it was removed from something else and soldered on. And a somewhat questionable LM317 charger. I’d only trust a 317 for a lead acid, but I guess if you’ve got a protection circuit the worst is just that you’ll reduce the battery life
I didn’t get too much time with it so I just took photos of the disassembly. Looks like there’s some boost converters, 2 PLLs (16-TSSOP parts), a micro to control them, and the VCOs. A very nice design! And I like the idea fitting it into a cigarette pack.Related