In-band spurious attenuation in LTE-class RFIC chip using a soft magnetic thin film

Abstract

A long term evolution (LTE)-class CMOS radio frequency integrated circuit (RFIC) receiver test element group (TEG) chip is developed in our project for the next generation cell phone handsets in order to clarify the on-chip-level noise coupling and demonstrate the noise attenuation using the soft magnetic thin film as an on-chip electromagnetic noise suppressor. The TEG chip equips a noise generator and a RF receiver block. The RF block amplifies and demodulates transmitted signals to IQ signals. A Co85Zr3Nb12 soft magnetic thin film is integrated onto the TEG chip as a noise suppressor. In this report, the noise generator is driven by a clock signal of 124.803 MHz and generates 17th harmonics of 2,165 MHz conflicts with the LTE band 1 (2,110 - 2,170 MHz). As a result, the in-band digital noise was suppressed 5-20 dB by the Co-Zr-Nb thin film as an integrated noise suppressor.