FM Radio Phones

Well FM radio spans 88-104 MHz. Cell starts at over 800 MHZ and goes way up from there.

So, the answer is that the frequency difference is very wide and you really need two receivers, with two antennas and circuitry to squelch the FM antenna whenever you turn on the cell phone to make a call. In fact, your cell phone actually transmits when you don't make a call, so it make cohabitation even harder.

Finally, nobody really cares for FM radio enough to make cell phone manufactures go through the hoops.

Excellent reply. Five points for it.

frequency bands are allocated for a purpose. Perhaps private FM can be embedded into Bluetooth 2.4GHz or higher frequencies open bands, spread spectrum. These are short range for home applications in which computer to camera, audio-video to head phone and projectors etc will also be seen in coming years.

Some bands are used as FSK (two frequencies switching and not full FM). These are near 151MHz, 434MHz, 868Mhz etc. Cell frequencies are generally near 900MHz. In India 900-1000MHz is not allowed for free band users or FSK or even spread spectrum communication, however, other countries permit spread spectrum use.

Frequencies are good point to argue that most cell phones has not FM radio on them .

I just wanted to say that my daugther has a Celphone with radio on it.

So it is posible and it is working, but as a guy before said... Who will buy a cell phone with FM radio?... at least one, my daugther, but not enough to make suppliers and developers to turn their focus on Mobile phones with FM radio on them.

Saludos!

Delmar

Cell phones do not use FM mod / demodulation they use digital pwm modulation which is pulsed and certainly nothing like FM...

John.

It is now broad band and spread spectrum in most of the cases where digital information is in packet form. This is the requirement set by IEEE for not to have too much power in any one frequency. FHSS is far better way to communicate with greater security. Perhaps with 10MHz spread, 1000 channels can be placed and then they can be time multiplexed to have some million callers on line in the zone. Radio and Video channels are downloaded packets played as files.