http://repository.iiitd.edu.in/xmlui/handle/123456789/1018 Year-2021 Fri, 10 Apr 2026 20:02:46 GMT 2026-04-10T20:02:46Z http://repository.iiitd.edu.in/xmlui/handle/123456789/1100 LDO with low quiescent current OTA and capacitance scaling circuit Bhardwaj, Aman; Hashmi, Mohammad S. (Advisor) The efficiency, dependability, and lifespan of any electronic system, particularly battery-powered and portable gadgets, are dependent on a specialized power management unit that offers a clean and controlled power supply. The need for a regulated power supply integrated on a single chip is increasing in various applications ranging from portable devices to biomedical-equipments, which linear regulators accomplish. One such linear regulator is the “Low Dropout Regulator” (LDO), which is utilized to achieve this control even when the power supply or load requirement fluctuates. LDOs are precise and have a quick transient response, making them ideal for controlling on-chip modules. A specific sort of error amplifier is constructed in this study employing an operational transconductance amplifier (OTA) followed by a buffer that switches on and off for specified load situations. The OTA design aims for a low quiescent current with a high gain, which is then utilized to create two proposed LDO circuits for low load and line regulations. A capacitance scaling circuit is designed for the latter suggested architecture of capacitorless LDO to replicate a nano-farad range capacitance from a picofarad-range on-chip capacitor. A 1.2 V bandgap reference with a start-up circuit is also designed for the reference voltage block. We present two LDO circuits in this work. The first is a capacitor-based LDO that uses a 1 μF off-chip capacitor to drive a maximum load current of 300 mA throughout a temperature range of -40o C to 125o C while maintaining a low quiescent current of 590nA – 201.4μA for no-load and max-load circumstances. With a maximum current efficiency of 99.93%, this design achieves load regulation of 0.0158mV/mA and line regulation of 9.47mV/mV. The other proposed design is a capacitorless LDO that uses a capacitance scaling circuit to incorporate a 100pF on-chip capacitor to drive a maximum load of 100mA from -40o C to a temperature range 125o C. The quiescent current varies between 433.9 and 616.6 μA. With a maximum current efficiency of 99.843 percent, this design achieves load regulation of 0.0181mV/mA and line regulation of 46.16mV/mV. Wed, 01 Dec 2021 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/1100 2021-12-01T00:00:00Z http://repository.iiitd.edu.in/xmlui/handle/123456789/1071 On the statistical characterization of the binomial line processes Sanyal, Souradip; Ghatak, Gourab (Advisor) This thesis introduces the Binomial Line Process (BLP) and then Binomial Line Cox Process (BLCP) based on BLP, a novel spatial stochastic model for the charac- terization of streets in the statistical evaluation of wireless and vehicular networks. Stochastic Geometry based network planning is an extensively studied area. Ex- isting models for streetwise millimeter wave network implementation include Pois- son line processes (PLP), Manhattan line processes (MLP), etc. However, all of these models lack an essential aspect of city-wide street network planning: street density is denser in the city center and sparse near the suburbs. These models simulate street networks by uniformly distributing the roads on the entire R 2 plane. Contrary to these models, the BLP model introduced here restricts the origin of the roads to a fixed circular area centered at the origin of the Euclidean plane, thereby artificially introducing inhomogeneity in street density with respect to the distance from the center. The idea being the further away we go from the city center, i.e., towards the suburbs, the sparser the entire network becomes. We have derived a closed-form expression for the contact distribution of the BLP from a random location on the plane. Leveraging this, we introduced the novel Binomial line Cox process (BLCP) to emulate points on individual lines of the BLP, where we derive the distribution of the distance of the nearest point of the Poisson line Cox process (PLCP) and the Probability Generating Functional (PGFL) of the PLCP. Based on the PGFL and the nearest point distribution, we characterize the Signal to Interference plus Noise Ratio (SINR) coverage of a network. Using these numerical results, we highlight that the network coverage characteristics from the perspective of a user at city center is remarkably different to that of a suburban user. This framework can be integrated with the existing models of line processes for a more accurate characterization of streets in urban and suburban environments. Wed, 01 Dec 2021 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/1071 2021-12-01T00:00:00Z http://repository.iiitd.edu.in/xmlui/handle/123456789/1059 Hierarchical codebook design for IRS assisted angular estimation of user position Bhat, Vaibhav; Ghatak, Gourab (Advisor) With the increase in demand for high-speed connectivity, millimeter-wave (mmwave) communication has received increasing attention from academia and industry due to its exceptional advantages. Compared to existing wireless communication tech- niques, such as Wi-Fi and 4G, mmwave communications operate at higher carrier frequencies and thus come with benefits including massive bandwidth, narrow beam, high transmission quality, and strong detection ability. Furthermore, highly direc- tional nature of mmwave help in localization of users in the network. On other hand, due to its high frequency, mmwaves are highly susceptible to attenuation and block- ages. Consequently, if the user is at a great distance from the source, then due to high atmospheric attenuation, that user is out of coverage. To deal with such scenar- ios, we have proposed a system which employs Intelligent Reflecting Surfaces (IRS), that helps in angular estimation of the positions of users that are far away from the Base Station(BS). Thus, it helps in estimating positions of users with higher accu- racy and provides better localization in a cellular network. Furthermore, we have proposed a hierarchical codebook approach to estimate angular positions of users, and we compared it with tradition methods like exhaustive search, showing how the proposed method is computationally more efficient. And, we have used Cramer Rao Lower Bound (CRLB) to observe the degradation of angular estimation performance as distance between IRS and users increase. We also used it to demonstrate improve- ment in angular estimation performance by increasing number of IRS elements. We found that IRS assisted system provides much better angular estimation of users po- sitions than a system with only a BS. Furthermore, we also found that Hierarchical codebook method is more computationally efficient than traditional methods like ex- haustive search. Wed, 01 Dec 2021 00:00:00 GMT http://repository.iiitd.edu.in/xmlui/handle/123456789/1059 2021-12-01T00:00:00Z