This paper describes the issues and tradeoffs in the design and monolithic implementation of direct-conversion receivers and proposes circuit techniques that can alleviate the drawbacks of this architecture. Following a brief study of heterodyne and image-reject topologies, the direct-conversion architecture is introduced and effects such as dc offset, I=Q mismatch, even-order distortion, flick...

iii ACKNOWLEDGEMENTS I wish to thank Dr. Komerath, my research advisor. It has been a true honor, to work with him in his research endeavors. In addition to the great opportunity he has given me, he has always listened to my ideas, and given me his confidence, respect, encouragement, and support. I am forever indebted. I would like to thank my mother and father for everything. I would like than...

A CMOS transceiver fully compliant with IEEE 802.11a in the unlicensed national information infrastructure (UNII) band (5.15–5.35 GHz) achieves a receiver sensitivity of 5 dBm for 64-QAM (quadrature amplitude modulation) with an error vector magnitude (EVM) of 29.3 dB. A single-sideband mixing technique for local-oscillator signal generation avoids frequency pulling. Realized in 0.18m CMOS and ...

This paper presents a 2.14GHz RF front end for Wide-band Code Division Multiple Access (WCDMA) receiver. The receiver is based on direct conversion architecture and implements a low noise amplifier (LNA) and a quadrature mixer in 0.25μm CMOS process. The receiver achieves a noise figure (NF) of 8.93dB, provides a gain of 17.14dB, has an IIP3 of -15.04dB and dissipate 72.15mW at 2.5V.

In the wireless communication systems, due to the increasing demands for high data rate and high efficiency, several practical challenges arise in the design of directconversion trans-mitters. According to the existing literatures, power amplifier (PA) nonlinearity and local oscillator (LO) pulling are the most critical factors to deteriorate the transmit signal quality. In this work, the above...

This paper presents a study of LO selfmixing and RF gain control issues in direct conversion receivers. In cellular systems, that use continuous time frequency duplexing, these can constitute serious problems. The presented topic is of special importance when digitally programmable gain is implemented at the RF frequencies before the downconversion mixers, practically in the LNA. Furthermore, t...

First receiver I was ever built for HF was tube receiver without RF amplification called OV2 .It was working good and enable me to listen short waves and HAM bands. After that I build super heterodyne receivers but when I built DC transceiver by W7EL at the beginning of 80’s ZL2BKW version I was surprised how good DC receiver can be. With simple dipole antenna for 7MHz I worked 102 DXCC in 1985...

Direct lineage conversion is a promising approach for disease modeling and regenerative medicine. Cell divisions play a key role in reprogramming of somatic cells to pluripotency, however their role in direct lineage conversion is not clear. Here we used transdifferentiation of fibroblasts into neuronal cells by forced expression of defined transcription factors as a model system to study the r...

This paper provides a tutorial overview of some recently developed methods for enhancing the accuracy and linearity of data converters (analog-todigital as well as digital-to-analog) by introducing auxiliary digital circuitry which calibrates, cancels and/or corrects the errors introduced by the unavoidable inaccuracy of the analog components used in the conversion. Simple but practical example...

Low voltage high-efficiency DC-DC conversion circuits are integral components of battery operated portable systems. This paper presents the design of a pulse width modulated (PWM) controller for a milliwatt level DC-DC converter. Low power control circuitry is constructed by utilizing a delay line based PWM generator and low-resolution feedback. A IDC-DC converter has been fabricated which deli...