Also included in this chapter is a discussion of the measurement results. FOMT for the oscillator is given by: Electrical Engineering and Computer Science. Resistors R1 and R2 are designed according to the values of capacitors C1 and C2. Both of these methods to approximate Kn only provide a general guideline for reference only.

Oxford University Press, Inc. As can be seen the design parameter values are different from what was calculated. Designing a higher Q inductor. The main function of the charge pump is to match the Iup and Idn currents. The main disadvantage to using this configuration is the difficulty in implementing it when the supply voltage is low due to the stacking of transistors. The above mentioned techniques along with some extra computations have been implemented to verify whether the proposed circuits can overcome the relaxation oscillations and can produce the proper sinusoidal waveforms or there is a need to devise some modifications.

quadrature vco thesis

Closed-loop PLL simulations for two loop bandwidths, 1 MHz and kHz, using a simple charge pump, PFD, loop filter, and Verilog-A divider confirm that settling time quavrature inversely proportional to bandwidth. However, with a real oscillator, noise generates fluctuation on the phase and amplitude of the signal, so the output becomes: The first method particularly will not result quadrahure a correct Kn value especially for advanced technology like TSMC nm, because square-law equations are not valid for short-channel transistors.

The thesis includes an analysis of single-sideband mixing, frequency dividers, and frequency multipliers, which are used to perform the four basic arithmetical operations for the frequency tone. The addition of the switched-capacitor provides extra coarse tuning that can be added to the normal fine tuning ie: However, the current source has the benefit of supplying a constant current to the cross-coupled differential pair of the LC-tank, making it less sensitive to voltage supply 7 variations [3].


The testbench schematic for Design B characterization is provided in Figure 5. Thus, the overall tuning range covered is from The amplitude is smaller than post-layout simulations, however is sufficient to indicate that the VCO is working well. Mayaram, Kartikeya Fiez, Terri.

Holistic Design In High-Speed Optical Interconnects – CaltechTHESIS

Last but not least I wish to thank my parents, who have always been there for me and whose support never faltered. This problem can be fixed by changing the design of the current source.

quadrature vco thesis

This is followed by a power generation method based fast start-up analysis of resonator based oscillators. However, the current should increase to ensure sufficient output swing. A final attempt to improve phase noise was to use a bias-T at Vtune with a battery. For a given current, this complementary topology offers higher transconductance. quadratur

Vtune for VCO tank 2. The consequence of this is the relatively low output amplitude. In some cases such as in [11], it has been reported that it may be advantageous to eliminate the tail current source to achieve better phase noise performance. The purpose of the inclusion of this section is so sufficient comparison can be made to the post-layout simulation results. Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.


At this state the output current is zero and the output is a high-impedance node. Note that the overall tuning range is skewed to allow for frequency drop after post-layout simulation due to parasitic capacitance.

Designing a higher Q inductor. Two loop filters are designed, one for loop bandwidth approximately 1 MHz and another for loop bandwidth approximately KHz. Phase-locked loops PLLs are widely used in telecommunication, radio, and computer applications.

Integrated RF oscillators and LO signal generation circuits

One method of loop filter design uses the open loop gain bandwidth and phase margin to determine the component values. The Design A prototype has a This will be elaborated in Chapter 7.

The derivation of the closed loop transfer function is shown below: In general, the tail current aids the designer in achieving a compromise between phase noise performance and power dissipation.

Finally, the spectrum analyzer is also used to measure phase noise.

Quadrature vco thesis

Methods of resolving them will be discussed in Section 7. Andre Ivanov and Dr. Some features of this site may not work without it.

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