PEMODELAN PHASE ROTATION & DEROTATION BAGI PENERAPAN BASEBAND IF TUNING BERBASIS SOFTWARE PADA RF-UPCONVERTER

Abstrak

RF-upconverter architecture can be a very important benchmark for achieving high efficiency and best linearityin driving a class switch mode amplifier (SMPA) amplifier. This scheme can generate the lowest noise (noise null) rightat the carrier frequency (fc). This paper aims to determine the accuracy of over sampled ratio (OSR) and offset variablesin the performance of the structured RF-upconverter and to study modeling through phase rotation & derotation as abaseband tuning application. The rotation process will be placed on the front side of the quantizer while the derotationprocess after the quantization process before loopback to the filter ΣΔ. With this methods, the distortion products willsignificantly move away from fc position. This study has also used channel tuning through large variable offset values asthe best solution. The joint quantization method has been applied to increase the quantization noise level which isproven to decrease noise floor up to 3dB. This scheme pattern is expected to deliver the desired signal to reach fc at thelowest noise floor while its harmonic distortions will be shifted away from the desired signal.