Ghannouchi, Fadhel M.Helaoui, MohamedEbrahimi, Mohammad Mojtaba2013-01-292016-02-112013-01-292013Ebrahimi, M. M. (2013). Delta-Sigma Based Transmitters for GHz Wireless Radio Systems (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25546http://hdl.handle.net/11023/526This dissertation was dedicated to improve the performance of the delta-sigma based transmitters in terms of efficiency and bandwidth without compromising signal quality. Delta-sigma based transmitter, consisted of two main blocks; delta-sigma modulator (DSM) and switching-mode power amplifier (SMPA), is one of the new promising techniques for wireless transmitters. To enhance the transmitter efficiency, the efficiency of the SMPA and the efficiency of the DSM were both addressed in this thesis. At first, by using class F and F-1 SMPAs was improved by proposing an analytical approach to decrease the output harmonic matching network loss. It was proven that, decreasing the width of the stubs minimizes the matching loss. The idea was tested by designing an inverse class F SMPA at 2.45 GHz, using a 10-Watt GaN transistor. It was also possible to increase the efficiency of the delta-sigma based transmitters by reducing the DSM’s quantization noise and improving its coding efficiency. Two signal processing techniques to reduce the quantization noise were proposed. In the first technique, conventional I/Q Cartesian DSMs were replaced by a complex DSM with a complex polar quantizer, resulting in a lower quantization noise and consequently higher efficiency. In the second technique, a part of out-of-band quantization noise was removed, resulting in a quasi-pulsed signal with lower noise and consequently better efficiency. These two techniques are also combined to further improve the efficiency. In the next step, the bandwidth enhancement in delta-sigma based transmitter was addressed. In the first technique, similarly to the noise reduction technique, in-band noise filtering is applied to reduce the in-band quantization noise and accordingly decrease the oversampling ratio required to achieve the desired signal quality. Another technique to reduce the DSM clock speed and increase the bandwidth is parallel processing. By employing a parallel processing technique based on time interleaving, the signal bandwidth of the DSM was increased without increasing the clock speed. Based on the proposed parallel DSMs, and the SMPA, an all-digital transmitter topology for SDR application was introduced and a three-step procedure for designing the transmitter’s parameters was proposed.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Engineering--Electronics and ElectricalDelta-SigmaPower AmplifierTransmitterEfficiencyBandwidthdoctoral thesis10.11575/PRISM/25546