| Summary: | 碩士 === 國立臺北科技大學 === 電腦與通訊研究所 === 101 === In the wireless communication system transceiver architecture, there are many components like voltage-controlled oscillator, mixer, low noise amplifier, antenna, etc. There are integral component in the transceiver system. How to design a low face noise, low voltage, low power consumption, and wide tuning range Voltage-Controlled Oscillator will be an important point with the process of modern radio frequency technology and popularity of radio frequency wireless communication devices. Upon completion of the front-end circuit should have an excellent antenna to transmitter and receive signals. How to design a suitable antenna for different conditions is the second key emphasis in this paper.
Thesis research can be divided into three parts. The first part explains loading effect caused by the crossed-coupled oscillator and load directly connected. In this thesis, voltage-controlled oscillator with low voltage and swing boosting is proposed to improve loading effect, low output swing, low output power, etc. On the other hand, the research explains how to use the analog tuning varactors and digital switching capacitor bank to boosting the VCO’s tuning range. Moreover, inductors are utilized on top of a cross-coupled pair for enhancing the negative conductance (-G m ) and resonate the parasitic capacitors.
The second part is showing how to realize this design methodology to easily overcome a VCO’s start-up condition. The fabricated 0.18-μm CMOS VCO exhibits a measured 25.63% tuning range. Operating at 0.75-V low supply voltage, the VCO core consumes 2.325-mW dc power. At this bias condition, the measured phase noise is -105.55 dBc/Hz at 1-MHz offset from a 11.311-GHz oscillation frequency. Compared to recently published VCOs in X band, the proposed VCO can simultaneously achieve low supply voltage, low dc power dissipation, low phase noise, and wide tuning range, leading to a superior figure of merit considering the tuning range (FOMT = -190.9 dBc/Hz).
The third part presents the realization of a L-band patch antenna with linear polarization for mobile device application. This patch antenna is constructed with two-sided structure and fabricated on FR4 substructure. It is fed by 50-Ω subminiature version A (SMA) connector with the patch size of 2.38 x 3.57 cm2.
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