An isotropic receiver for area discrimination with magnetoquasistatic fields

We propose the concept of area discrimination with magnetoquasistatic (MQS) fields. Unlike radio waves, MQS fields are valid for forming a clearly defined area whose radius is below about 1 meter. Such an area can be utilized for identification of persons with mobile terminals. Since an important characteristic required for the terminals is isotropy in receiving magnetic fields, we made an isotropic receiver equipped with a 3-axis loop antenna. It is experimentally demonstrated that the receiver possesses sufficient isotropy. With the isotropic receiver, we measured areas formed by MQS fields at 10 MHz and demonstrated that MQS fields are useful for forming a clearly defined area for identification of mobile terminals.