A high CMRR BiCMOS active combiner balun

Abstract

both configurations. This difference is not detected by measurement. This is probably due to the fact that the axial ratio is an extremely sensitive parameter and it is very difficult to verify small differences. CONCLUDING REMARKSStudies of the two designs for CP utilizing U-slots etched on a square patch have been presented for both air and material substrates. Both designs are simple, and require only a single probe feed. In the first design, the truncated square patch generates circular polarization while the symmetric U-slot allows the use of thick substrates as it broadens the RLBW and tunes the ARBW to overlap with the RLBW. In the second design, the asymmetric U-slot performs all the above functions. The studies show that, for the same substrate thickness, both the bandwidth and the gain of the symmetric design are somewhat better than the asymmetric design. REFERENCES