Polar quantizer for next generation wireless receiver

This dissertation presents the theory and analysis of IF polar receiver (PRX) architecture. By using new quantization techniques in the polar domain, the proposed receiver can boost the signal to quantization noise ratio (SQNR) compared to a traditional rectangular (I/Q) receiver. The proposed PRX is composed of a magnitude and a phase quantizer. The magnitude quantizer is similar to the conventional rectangular quantizer in voltage domain. The phase quantizer employs a time-to-digital converter (TDC) for phase detection. Furthermore, an intuitive graphical method is used to analyze the polar quantization properties. A 10 bit polar quantizer is designed and fabricated in 130nm CMOS, and achieves 2- to 5-dB of SQNR improvement compared to rectangular quantizer for signal bandwidth as high as 20MHz.;The latter part of the dissertation offers the characterization of an SQNR enhancement technique employed in a polar quantizer for wireless signals with complex Gaussian probability density functions (PDFs). The proposed technique is based on segmentation of polar space, and can boost the SQNR of the quantizer significantly compared to that of the conventional rectangular and polar quantizers. First, an N-segmentation technique is examined using N different bit allocations for magnitude and phase quantizers. The study then covers a polar quantizer incorporating 3-segmentation technique for practical implementation. Using this technique, the overall maximum SQNR of the polar quantizer improves about 2.5 dB higher than the rectangular quantizer. In addition, over 14 dB SQNR improvement at low average magnitude is achieved if equal numbers of quantization levels for both polar and rectangular quantizers are utilized.