In a recent paper, we modified the Bilow's diffracted current basis function both within and outside the transition regions to solve the problem that the combined moment method (MM)-physical optics (PO) approach proposed by Bilow fails for some cases. The two expressions are discontinuous when the wedge face is going from outside the transition region to within the transition region. Then, the previous procedure yields nontrivial errors when the transition region is approaching the wedge face. Uniform expressions for the diffracted currents on the wedge surface are derived in this paper.
We have first fabricated and characterized Ti-diffused channel waveguides on Er-doped LiNbO3 single crystal. We achieved an optical gain of 2.1dB/cm at 1531.4nm signal light (TM mode) by optical pumping at 1480nm with pump power of 200mW/port for a 40mm long Ti-diffused Z-cut 0.5mol% Er-doped LiNbO3 waveguide. The total gain of a pig tailed device was 3.8dB.
A new technique for addressing the challenging dynamic range required by CMOS multi-standard Zero-IF GSM and UMTS receivers is presented in this paper. This is achieved by LC tuning of the parasitic capacitors of mixer switching transistors in different frequency bands with an easily reconfigured new integrated variable inductor. Using this technique, a high IIP2 low noise mixer supporting DCS, PCS, UMTS and IEEE802.11 b-g standards is designed. The mixer achieves IIP2 higher than 70dBm while the input refereed noise performance is 5 and 3.5nv/sqrt(Hz) in DCS/PCS and UMTS respectively. The design is done in 65nm CMOS technology.