In concept, a cellphone jammer is pretty simple. It transmits signals on the same frequency as a cell phone which disrupts the radiowaves. I’ve had the circuit below in my collection of electronics schematics for quite some time. It’s really two circuits – a transmitter and a noise generator.
You’ll need a LM1458 op amp and a LM386 low voltage amplifier (or equivalent). The Micronetics M3500 is a Voltage Controlled Oscillators and can be replaced with a similar component. Finally, the ICL7660 is a CMOS switched-capacitor voltage converter. Don’t forget that you’ll need an antenna too.
