Re: cell phone jammer
well i don't have the diagram but i can provide you some idea...
well our cell phones operate on 1800-2400 Mhz Career band...so if you just make a circuit which would osciate an produce frequencies between 1800 and 2400 Mhz then the signals from the service provider will not be accepted by the cellphone as your signals will have a stronger power (for a specific area), and this will now allow any other same frequency career to reach near.
Best Regards