Patent ID: 7724203

Claim:
A communication system comprising: a sheet-like signal carrying apparatus ( 101 ) for carrying a signal by variation of an electromagnetic field; and an interface device for carrying a signal between the interface device and the signal carrying apparatus ( 101 ), wherein (a) the signal carrying apparatus ( 101 ) includes: a first conductor portion ( 111 ) of which an external shape is sheet-like and which serves as a conductor in a frequency band ω/(2π) of the electromagnetic field; and a second conductor portion ( 121 ) of which an external shape is sheet-like and which serves as a conductor in the frequency band ω/(2π) of the electromagnetic field and arranged substantially in parallel with the first conductor portion ( 111 ) and spaced from the first conductor portion ( 111 ) by a distance h; (b) the interface device ( 1201 ) includes: a first electrode ( 1211 ) having a surface located near the first conductor portion ( 111 ) and a second electrode ( 1222 ) having a surface located near the first conductor portion ( 111 ) and disposed at a position different from that where the first electrode ( 1211 ) is located; and (c) wherein for normalized sheet reactance γ defined as γ=X∈ 2 /[hω(∈ 2 μ 2 −∈ 1 μ 1 ], normalized distance η defined as η=H∈ 2 /(h∈ 1 ) to a distance H between at least one of the electrodes ( 1211 , 1222 ) and the first conductor portion ( 111 ), wherein dielectric constant ∈ 2 of an interval region ( 131 ) between the first conductor portion ( 111 ) and the second conductor portion ( 1222 ) magnetic permeability μ 2 of the interval region ( 131 ), reactance component X of sheet impedance σ=E x /I x =r+jX which is the ratio of electric field E x in the surface expansion direction of the first conductor portion ( 111 ) on the surface thereof to current density I x , dielectric constant ∈ 1 of the leak region ( 141 ) between at least one electrode out of the first electrode ( 1211 ) and the second electrode ( 1222 ) and the first conductor portion ( 111 ) and magnetic permeability μ 1 of the leak region ( 141 ), an electromagnetic wave is carried in a surface expansion direction of the first conductor portion ( 111 ) in the leak region ( 141 ) and the interval region ( 131 ) due to the disposition of the interface device ( 1201 ) and the signal carrying apparatus ( 101 ) with respect to each other so that the normalized distance η is smaller than a maximum normalized distance η max which is the upper limit value of the normalized distance η defined for a desired efficiency of electromagnetic energy absorption and the normalized sheet reactance y.