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A flat-gain design of an ultra wide-band CMOS amplifier is proposed and simulated in 90 nm CMOS process. Inductive degeneration is applied to reduce noise figure without significantly raising the architecture’s power requirement. Additionally, a resistive shunt feedback technique is applied with an RL peaking load to flatten the gain throughout design band. This topology allows the amplifier to have a very large bandwidth of 6.9-17.7 GHz with a low minimum noise figure of 2.26 dB (at 10 GHz). NF also remains below 5.2 dB across the 10.8 GHz bandwidth. The design exhibits gain which peaks to 11.1 dB and has a low power demand of 15.7 mW (from a 1.2 V supply). Comparing the circuit performance to previously published amplifiers shows that it achieves reduction in NF and power dissipation while maintaining a flatter gain in X-K band.

Figure 6.12a illustrates a squirrel-cage rotor of an induction motor that is operating at no load (near synchronous speed). The magnetization current IM flowing in the motor's equivalent circuit (Fig. 6.7) creates the net magnetic field Bnet. Current IM and hence Bnet are proportional to E1. Since E1 remains constant with the changes in load, then IM and Bnet remain constant also. At no load (Fig. 6.12a), the rotor slip (the relative motion between the rotor and the magnetic fields) and the rotor frequency are very small. Since the relative motion is small, the induced voltage in the rotor bars ER is very small and the resulting current IR is small. Also, since the rotor frequency is small (fr sfe), the reactance of the rotor (XR sXR) is negligible, and the maximum rotor current IR is almost in phase with the rotor voltage ER. The induced torque in this region is small (just enough to overcome the motor's rota-tional losses) because the rotor magnetic field is quite small. When the motor is loaded down (Fig. 6.12b), the slip increases and the rotor speed falls. Now there is more relative motion between the rotor and the magnetic fields because the rotor speed is slower. Higher rotor voltage ER is now produced because of the higher relative motion. This in turn produces a larger rotor current IR. the resulting torque-speed characteristic is shown in Fig. 6.13. The torque-speed curve is divided into three regions. The first is the low-slip region. In this region, the motor slip

This paper describes the LC tank design for low phase noise LC VCO on the selection of passive elements. LC tank based VCO is commonly used for the low phase noise performance in most RF applications. Since quality factor of the LC tank is mainly dominated by the quality factor of the passive elements (inductor & capacitor) selection, this work presents the passive elements optimization based on the inductor and varactor optimization. Simulated in 65 nm process, higher Q is obtained for large width and minimum number of turns for the inductor and for the varactor design; the PMOS varactor operating in the depletion and accumulation regions allows large tuning range and less parasitic resistance.

In this letter, parameter estimation of a uniformly sampled signal that satisfies the lossy wave equation in Gaussian noise is investigated. By exploiting the linear prediction property of the noise-free signal, a maximum likelihood estimator for the parameters is first developed. Relaxation is then applied to yield a simple and accurate algorithm. It is shown that the estimation performance of the proposed method attains Cramér-Rao lower bound.

In this paper, a recursive Gauss-Newton (RGN) algorithm is first developed for adaptive tracking of the amplitude, frequency and phase of a real sinusoid signal in additive white noise. The derived algorithm is then simplified for computational complexity reduction as well as improved with the use of multiple forgetting factor (MFF) technique to provide a flexible way of keeping track of the parameters with different rates. The effectiveness of the simplified MFF-RGN scheme in sinusoidal parameter tracking is demonstrated via computer simulations.

The problem of parameter estimation of a single sinusoid with unknown offset in additive Gaussian noise is addressed. After deriving the linear prediction property of the noise-free signal, the maximum likelihood estimator for the frequency parameter is developed. The optimum estimator is relaxed according to the iterative quadratic maximum likelihood technique. The remaining parameters are then solved in a linear least squares manner. Theoretical variance expression of the frequency estimate based on high signal-to-noise ratio assumption is also derived. Simulation results show that the proposed algorithm can give optimum estimation performance and is superior to the nonlinear least squares approach.

This paper describes an ultra-low-voltage low-power 8-phase voltage-controlled oscillator (VCO) for 10GHz beam-forming satellite receivers. It is composed by four 0.5V current-reuse LC-VCO cells interlocked by direct-back-gate coupling, featuring independent sizing of coupling strength and frequency tuning, while avoiding the risk of forward bias the substrate p-n junctions. Optimized in 65nm CMOS, the 8-phase VCO draws only 2mW. The phase noise at 1MHz offset is-114dBc/Hz to-110dBc/Hz over a 32.5% tuning range from 8.55 to 11.88GHz. These results correspond to a high-and-stable FOM within-188 to-189.5dBc/Hz.

This article proposes a tunable active inductor (AI)-based voltage-controlled oscillator (VCO) andbandpass filters (BPF) on a single integrated design in 90 nm CMOS process for wireless applications. By exploiting component sharing technique through single pole double throws switching method, a common AI is shared between VCO and BPFs. As the passive inductor is replaced by the AI and shared, silicon area consumption is significantly reduced. Transforming the inductor in tunable mode benefits to eliminate MOS varactors for tuning purposes ; one step forward to reduce silicon area consumption. Operating as VCO, its frequency ranges from 1.93 to 6.22 GHz (tuning scope is 105%) for tuning voltage of 0.2 ∼ 1 V. The DC power consumption varies from 1.83 to 3.84 mW, and differential output power is 3.39 to − 2.99 dBm. The phase noise varies from − 81.32 to − 76.89 dBc/Hz, and the figure of merit has a value of − 148.74 dBc/Hz at 5.03 GHz frequency. While acting as BPF, two approaches of center frequency tuning are applied. The voltage tuning yields center frequency of 8.43 ∼ 7.08 GHz along with the maximum gain of 10.29 dB at 7.81 GHz. The capacitive tuning outputs frequency tuning of 7.64 ∼ 7.06 GHz. The BPF consumes DC power of 2.56 to 2.27 mW (voltage tuning) and 2.40 mW (capacitive tuning). The proposed design occupies a layout area of 1215.6 μm 2. All the simulations have been performed considering parasitic elements evolved from the extraction of layout. Finally, a quantitative comparison and justification of the proposed design are made with respect to other published works. K E Y W O R D S active inductor, BPF, DC power consumption, frequency, phase noise, VCO 1 INTRODUCTION The acceleration of leading-edge communication systems is making performance efficient radio frequency integrated circuits (RFICs) highly demandable. Voltage-controlled oscillators (VCOs) with extensive tuning range are fundamental blocks of almost all RFICs for multiband and multi-standard applications. 1 In the evolving era of Internet of things (IoT), This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

This paper presents active inductor based VCO design for wireless applications based on analysis of active inductor models (Weng-Kuo Cascode active inductor & Liang Regular Cascode active inductor) with feedback resistor technique. Embedment of feedback resistor results in the increment of inductance as well as the quality factor whereas the values are 125.6@2.4GHz (Liang) and 98.7@3.4GHz (Weng- Kuo). The Weng-Kuo active inductor based VCO shows a tuning frequency of 1.765GHz ~2.430GHz (31.7%), while consuming a power of 2.60 mW and phase noise of -84.15 dBc/Hz@1MHz offset. On the other hand, Liang active inductor based VCO shows a frequency range of 1.897GHz ~2.522GHz (28.28%), while consuming a power of 1.40 mW and phase noise of -80.79 dBc/Hz@1MHz offset. Comparing Figure-of-Merit (FoM), power consumption, output power and stability in performance, designed active inductor based VCOs outperform with the state-of-the-art.

The use of ultra-wideband (UWB) in target detection, radar and wireless connectivity, specifically in the medical world, has attracted a lot of attention. The concept that the IR-UWB system does not necessarily require carrier signals is one of its most appealing features. IR-UWB can transmit information using short Gaussian monocycle pulses. In light of these advantages, this paper proposes a novel UWB transmitter system which consists of UWB signal generating circuits and UWB antenna, which work together to create entire UWB transmitter. It is based on impulses and has a simple architecture with low power consumption. The proposed transmitter is realized in Cadence tools with 90nm CMOS technology and proposed UWB antenna is simulated using Advanced Design System (ADS) simulator software. In addition, the transmitter circuit and the antenna are co-simulated using ADS software. The illustrated UWB transmitter uses a low-power supply and generates pulse amplitude with pulse duration of for the Gaussian monocycle pulse. Due to its increased output voltage swing and reduced power consumption when comparing to other circuits, the proposed architecture is functional and suitable for use in short-range wireless networks and medical applications.