Ultra-wideband (UWB) RF front-end module implementation for multi-band OFDM system

In this paper, we demonstrated the implementation of an LTCC-based ultra-wideband (UWB) front-end module that encompasses a wideband antenna, an impedance transformer, an LNA, and a harmonic VCO with very low power operation. The wideband asymmetric spiral antenna with an impedance transformer are implemented on a multilayer LTCC substrate while the LNA and the VCO are fabricated in 0.18/spl mu/m SiGe BiCMOS process. A novel multilayer impedance transformer topology, where a line type was gradually changed from CPW with ground plane to CPW without ground plane, is proposed and implemented. The fabricated LNA achieves gain of 13dB with NF of 3.3dB up to 10GHz while the harmonic VCO generates the LO signal from 1.52GHz up to 8GHz. To the best of authors' knowledge, this is the first demonstration of UWB antenna and RF front-end module for the multi-band OFDM system with very low power consumption of approximately 25mW.