New Japan Radio and wireless technology start-up Superwave have develop a chip that uses weak radio waves to communicate with mobile phones.

So what?

It means handsets devices can be made that tell users when a handset is misplaced.

The new chip exchanges radio waves in the 300MHz band with mobile phones every few seconds, enabling mutual recognition within a radius of 3-5 meters. By mounting the chip on a small device, users could be alerted by sound or vibration if they forgot their mobile phone on the train, for example.

Oh I get it now. You carry an extra device, to help you remember not to lose your original device. It's going to get very crowded in my pockets. But hang on, if you're the type of person who loses your mobile phone, surely you're going to be the type who loses the mobile finding gadget too. Unless it's a tiny little thing you can put on a belt, or in your underpants. So when your phone gets out of range, it starts vibrating.

The makers envision use in portable devices, according to Nikkei.net. The chip has an energy-saving design that employs CMOS (complimentary metal oxide semiconductors). It consumes 10 milliamps when sending or receiving a signal and 10 microamps otherwise. A single chip includes both an analog circuit for sending and receiving signals and microcomputer circuitry for recording and signal encryption.

Expect samples to emerge in October.