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In this paper, the adaptive feedback interference cancellation system(AF-ICS) is suggested in order to cancel the feedback signal in the wireless communication system with the same frequency. AF-ICS prevents the oscillation of the receiver system and maintain the maximum output power of the power amplifier by the reduction of timevarflng feedback signal. The cancellation ratio and the error ratio of the adaptive detector are achieved as simulation result of 4 0 4 4 dB and the performance index(cancel1ation ratio and error ratio) of the adaptive detector is 13-15 dB in the system implementation. AF-ICS improves total channel power about 4.11 dBm under CDMA-3FA and 90 dB feedback loss.

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We demonstrate theoretically that the analogue of electromagnetically induced transparency (EIT) in two orthogonal directions can be achieved in a planar metamaterial consisting of spiral resonators and split ring resonators in the same plane. The metamaterial can exhibit EIT-like effect to both normally and laterally incident electromagnetic waves because of its electric and magnetic response, respectively. Full-wave numerical simulations are carried out to validate the EIT-like effect of the planar metamaterial. Absorption curves, transmission spectra, surface current distributions and effective constitutive parameters of the metamaterial illuminated by normally and laterally incident EM waves are presented. These results, showing a transparency window with extremely low absorption and strong dispersion, are in good agreement with each other.

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