The peak-to-peak voltage is also measured using the spectrum analyzer. Also, it is often ideal to design higher frequency VCOs and then lower its frequency through the use of a divider in the closed-loop PLL, as higher frequency LC-VCOs are implemented with smaller inductors which occupy smaller area. Verkkokirja KB, s. Adding an inductor in the current source to remove upconverted flicker noise. Electrical engineering , Telecommunications engineering Keywords:

It discusses the basic operation of the PLL. The ring oscillator is a commonly used oscillator for integrated PLLs and clock recovery circuits because it is less complex and easy to integrate. To load this item in other compatible viewers, use this url: Attaran, “Performance review of high-quality-factor, low- noise, and wideband radio-frequency lc-vco for wirless communication,” IEEE Microwave Magazine, vol. Conversely, if the working frequency is decreased, the resistance should increase, and the current should decrease to keep the output swing constant. At very small offset frequencies the spectrum becomes flat again [25]. If a phase error builds up, a control mechanism directs the output signal to minimize the phase error with the input signal.

Active loop filters usually consume less area and usually allow for more design flexibility [56]. The design implemented is the same as that discussed in Section 6.

As indicated, at 1 MHz offset, the phase noise is — Optical links present a viable alternative due to their low frequency-dependent loss and higher bandwidth density in the form of wavelength division multiplexing. The first PLL was introduced in and today, decades later, there are still many people researching this quasrature [3].

Lastly, a first-order frequency synthesizer that is suitable for high-speed on-chip clock generation will be discussed. Once the loop starts up, M3 will come on, sinking the current from the cascode M5 and M6 and pulling the gate of M1 low, thus turning it off [23]. In terms of power dissipation, assuming that the Quadrahure cores of both Designs A and B dissipate about the same amount of power, the overall power consumption of the structures would be about the same. In general, the tail current aids the designer in achieving a compromise between phase noise performance and power dissipation.


This is because settling time is inversely proportional to bandwidth.

quadrature vco thesis

Since for the source follower the source is the output node, the transistor becomes dependent on the body effect. The first one, Design A, is implemented using two VCO cores and the overlapping tuning ranges of the two cores together give overall tuning range. The aspect ratio of the cross-coupled NMOS transistor of the VCO cores varied quite a bit from the calculated value which provided a guideline.

Without knowing exactly what the factor F depends on, it is difficult to identify specific methods of reducing it. An adaptive body-biasing circuit is designed to maintain the per-bit-energy consumption constant across wide data-rates.

Integrated RF oscillators and LO signal generation circuits

The combined task of the PFD, charge pump, and loop filter blocks is to provide a stable DC tuning voltage to the VCO based on the frequency and phase difference between the reference frequency and output of the divider so that acquisition of the PLL can be achieved.

Thank you for your help, keeping me focused, and most importantly for your kindness thesjs encouragement. The first method is to use the value of tox to first calculate Cox.

Tampereen teknillinen yliopisto – Tampere University of Technology. Electrical Engineering and Computer Science. The measured phase noise of Design A is slightly worse than that of 51 Design B, contrary to post-layout results; the reason again can be attributed to the lower measured amplitude of Design A compared to post-layout simulations and compared to the lower measured amplitude of Design A compared to Design B.


Verkkokirja KB, s. The pull-up resistors were chosen depending on the working frequency and output swing.

Integrated RF oscillators and LO signal generation circuits

The Verilog-A divider used is similar to that described in [62]. The implemented design of the CML stage is shown in Figure 3. The nm CMOS prototypes operate from a supply of 1. Step 2 After determining the geometry of the VCO, the next step is to do initial hand calculations to find the values for the resistors and the varactors of VCO 1 with center frequency Another importance of the quadratuure of wide-tuning range PLLs is that it is a practical method in dealing with quavrature and process variations.

quadrature vco thesis

Vtune for VCO tank 2. The peak-to-peak voltage is also measured using the spectrum analyzer. The purpose of the inclusion of this section is so sufficient comparison can be made to the post-layout simulation results.

Phase-locked loops PLLs are widely used in telecommunication, radio, and computer bco. Martin, Analog Integrated Circuit Design.: The main function of the loop filter is to filter out the phase noise by removing glitches from the charge pump.

Quadratuee application of this analysis to the design optimization of LC oscillators is also demonstrated.

Extra poles and zeroes can be thesiss in the loop transfer function; these influence the noise and dynamic performance of the loop [31]. Next, on the optical transmitter side, three new techniques will be presented.