Wave attenuator by high dielectric corrugate chip for the mobile telephone hand-set

The field attenuation can be approximately obtained by the mode cutoff characteristic of the corrugate propagation. The wave attenuator, which attenuates the field towards the human brain with no effect in the other direction, was designed by the use of mode theory. The corrugate chip consists of 20 micron silver conductive electrodes and a ceramic material of relative dielectric constant 300. Measurement showed a 3.6-5 dB and a 5.6-10 dB attenuation in the 824-950 MHz and 1850-1910 MHz frequency bands respectively.