The second technique is thermal stabilization of micro-ring resonator modulators through direct measurement of temperature using a monolithic PTAT temperature sensor. This AC coupling block consists of two capacitors and four resistors. Doing so would result in even larger overall tuning range, at the expense of increased phase noise and parasitic capacitance because the Q would be decreased. Finally, two frequency synthesizers for UWB radios are presented. The first VCO was designed to cover the frequency range As bandwidth requirements for chip-to-chip interconnection scale, deficiencies of electrical channels become more apparent. Finally, the loop filter is the component most commonly used to control system-level loop dynamics [53].

A Caltech Library Service. When dead zone is present in a synthesizer, until the phase difference reaches a certain value, the loop fails to correct the error resulting in the VCO control voltage not being able to change as desired [47]. This task was not easy as both switched-capacitor turned off and on had to be considered and sufficient overlapping of tuning range must be guaranteed. It can act not only as a phase detector but also as a frequency detector, detecting both phase and frequency difference between two signals and generating an output that represents that difference [47]. The W and L of transistors M1 and M2 were chosen to be as small as possible to reduce the input capacitance and therefore reduce the source follower load, since the input capacitance CGS is proportional to W and L [23] as shown as follows: Commercial use is prohibited.

Quadrature vco thesis

The balanced symmetrical design of the switched-capacitor has a common-mode node and allows for better linearity and phase noise performance compared to a switched-capacitor with no common-mode node [31]. Also, it is often ideal to design higher frequency VCOs and then lower its frequency through the thessi of a divider in the closed-loop PLL, as higher frequency LC-VCOs are implemented with smaller inductors which occupy smaller area.

Thus, careful consideration of the delay length of the PFD is crucial [50].


quadrature vco thesis

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. Some features of this site may not work without it. When the reference clock and the feedback clock are aligned, the PLL is considered locked. The VCO with the switched- capacitor turned off will be designed to cover the frequency range of approximately 14 GHz to Measured results show However, the amplitude for PMOS is smaller and therefore the quadature noise worse [1].

Holistic Design In High-Speed Optical Interconnects – CaltechTHESIS

In some cases such as in [11], it has been reported thfsis it may be advantageous to eliminate the tail current source to achieve better phase noise performance. A simple capacitor by itself does not yield a stable loop; therefore, a combination of capacitors and resistors is usually used [53]. If the working frequency is increased, the resistance should decrease because they are inversely related. Resistors R1 and R2 must be equal to ensure that the signal is even and has the same amplitude above and below common-mode level.

A typical wide-tuning-range LC-VCO employs the use of a switched capacitor network for coarse tuning and a varactor for fine tuning, such as in [17,18]. Quadratur oscillators Wireless sensor networks.

Integrated RF oscillators and LO signal generation circuits

Initial simulations indicated that the target tuning range was not possible for this design with only one switched-capacitor for a fair comparison, so the goal was altered to maximize tuning range. Quqdrature would not be able to go this far without you.

Electrical and Computer Engineering. As integrated photonics and bonding technologies are maturing, commercialization of hybrid-integrated optical links are becoming a reality. A description rhesis the tests is also given as well as illustration of the test setup using testbench schematics. Alternatively, a wide- tuning-range VCO can be implemented by using switched inductors as in [21].


quadrature vco thesis

JavaScript is disabled for your browser. It is important to note that flicker noise is inversely proportional to the transistor area WL; thus, larger devices have less flicker noise [23]. Flicker noise is a significant noise source in MOS transistors.

The proposed oscillator has a superior start-up performance compared ghesis other low voltage quadrature LC oscillator architectures. Elektroniikan ja tietoliikennetekniikan laitos — Department of Electronics and Communications Engineering.

A study of two wideband CMOS LC-VCO structures – UBC Library Open Collections

However, a major drawback of the ring oscillator is that its phase noise is inferior, which impedes its use in high-quality communication systems. The type of the loop is the number of perfect 60 integrators in thesiz loop; because of the perfect integration in the VCO, every PLL is at least type-I [1].

quadratjre In terms of power dissipation, assuming that the VCO 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.

This model of the real inductor is a very simplified model and does not take into consideration the parasitic capacitance and resistance of the inductor but is sufficient for our purposes.

quadrature vco thesis

The target center frequency, like that for Design A, is 13 GHz. A simple model of the charge pump circuit together with a capacitor representing the loop filter is shown in Figure 6. Summary View Show full item record. An adaptive body-biasing circuit is designed to maintain the per-bit-energy consumption constant across wide data-rates. Vtune for VCO tank 2. The loop filter then converts these signals to a control voltage that is used to control the VCO.