Traditionally resonators for band-pass CT ΣΔ modulators have been realized by RLC parallel circuits with spiral inductors. Such circuits occupy a large silicon area. Spiral inductors also have low quality factors. Activeinductorbased RLC circuits occupy a much smaller area, and when Q enhancement techniques are used, high quality factors can be achieved. The activeinductorbased resonator is explained by the gyrator C theorem as shown in Fig. 4 below.
Due to an increasing demand for simultaneous global roaming and all-in-one wireless phones, the interest in the development of the multi-standard transceivers has been increased. In the receiver front end, the performance of Low Noise Amplifier (LNA) decides overall receiver sensitivity and hence its design plays a crucial role. In this paper, an activeinductorbased tunable two-stage LNA employing current reuse technique is proposed for multi- standard applications. The LNA is aimed at supporting CDMA-2000, GSM, WCDMA, WiMAX, Bluetooth and UMTS-TDD in the bandwidth range of 1.7 – 2.5 GHz. The proposed LNA achieved a power gain of greater than 13 dB, noise figure less than 2 dB and impedance matching less than –8 dB for all the standards. The stability factor is maintained above 1, ensuring stable operation of the LNA without oscillations. The LNA consumes very low power of 7.96 mW at an operating voltage of 1V. The performance analysis of the proposed activeinductorbased tunable LNA is carried out using Agilent‟s ADS simulator employing 90 nm CMOS technology.
This paper presents a study of Activeinductorbased VCOs that helps in increasing the tuning range of the VCO , reduces the chip size and phase noise of the circuit. Study has been done on LC VCOs by replacing the passive inductors with the active one consisting of MOSFET. Design of circuit has been done on Orcade Capture using .18um technology.power consumption of circuit is 1.33mW with tuning range of 81%.Tuning range of the VCO is increased because the activeinductor cancels out the parasitic capacitance of the circuit.
MB-OFDM transmits information over multiple carriers. The MB-OFDM based UWB technique uses the whole spectrum by dividing it into 14 bands . This is organized into five groups with each group having bandwidth greater than 500 MHz. The operation within the first group is mandatory, while all the other groups are optional. This is illustrated in Fig. 2. Being the first signal processing element in the analog front- end circuits, serious challenges exist for the realization of LNA. The received UWB signal exhibits very low Power- Spectral Density (PSD) at the receiver antenna. The primary goal of LNA is to amplify the weak signal received from the antenna with less distortion and little self generated noise . Major metrics used to measure the performance of LNA are reduced noise figure, moderated gain, input & output impedance matching, low power consumption, isolation between input and output, acceptable linearity (low distortion) and stability.
The results indicate that conventional load 1:8 demultiplexer has improved delay parameters when compared to PMOS load 1:8 demultiplexer. As at these frequencies PMOS load requires small channel resistance and thus infers large transistor sizes which increases the parasitic capacitance values associated with the output nodes. For this reason, in some circuit configurations, conventional load gates allow operation at high frequencies as compared to PMOS load counterparts. Further, by using an activeinductor load instead of conventional load, the fall time of 1:8 demultiplexer at 5 Gbps decreases from 323 ps to 57 ps which represents an improvement of about 82%. Also the results for rise time show an enhancement of 18.7% over the conventional demultiplexer. Power consumption results depict that at high speed of operation, circuits with conventional load has maximum power consumption whereas the circuits with activeinductor load consumes the least power. Thus, the proposed activeinductorbased implementation of 1:8 demultiplexer is best suited in terms of speed and power for high frequency operations.
The Gm-C filters have the privilege that it can operate at very small voltages by means of transconductance tuning [22, 35]. Despite of operating the MOS devices in the weak inversion, the Gm stage is able to support filter applications in the range of KHz upto few MHz. This type of filter usually have a linearly current-controlled transconductance as well as tuning frequency characteristics . One of the best transconductance control methodology is based on the master-slave technique using the control circuit . In order to achieve both, low-voltage operation and transconductance tuning, the bulk terminals of the transistors are generally not connected to constant voltages as in conventional circuit topologies, but they are used to adjust their bias. Biquad topology as well as low power transconductor architectures can also be adopted to obtain desired tuning at very low voltages [35, 37]. Triode-biased input MOSFETs whose transconductance is widely tuned with drain bias is adopted, it can ensure wide frequency tuning of the filter . Besides in these filters, the Q factor can be boosted up with negative-Gm cells in parallel at the output .
Power device utility and average switching frequency between QC 1, QC 2 and QC 3, QC 4 in the circulating modes of the inductor cell current is one of the considerations to use redundant switching states for I, 0, and −I output-current generation. It is also related to the heat distribution among the power switches QC 1, QC 2, QC 3 , and QC 4 caused by the switching and conduction losses.
ABSTRACT: This paper proposes a new coupled inductorbased SIMO interleaved step down converter. Multiple output converters are widely used in industrial applications. Designing multi-output converters presents a remarkable challenge for the power supply designers. Converters utilizing a single primary power stage and generating more than one isolated output voltage are called multi-output converters. The basic requirements are small size and high efficiency. This paper mainly investigates a high efficiency coupled inductorbased single input multiple output (SIMO) interleavedstep down converter. The proposed converter can step down the voltage of high voltage dc bus generated by the rectifier of an AC utility power to a controllable output voltage of different levels. The interleaved topology of the proposed converter can achieve high step down conversion ratio, high efficiency power conversion and reduced voltage ripples across the load.
Interleaved buck and boost converters have been studied in recent years with the goal of improving power-converter performance in terms of size, efficiency, conducted electromagnetic emission and also transient response. The gains of interleaving consist of high power potential, modularity and better reliability. Since the inductor is frequently the largest and heaviest component in a high-boost converter, the use of a coupled inductor as a substitute of multiple discrete inductors is potentially beneficial. The coupled inductors also offer additional benefits such as reduced core and winding losses as well as better input and inductor current ripple. Generalized steady-state analysis of multiphase IBCs has been previously reported. Useful design equations for continuous inductor current mode (CICM) operation of an IBC, including the effects of inductor coupling on the key converter performance parameters (inductor ripple current, input ripple current, and minimum load current requirement for achieving CICM operation), are detailed in Reports studying specific applications for coupled inductor topologies including soft switching, active clamping, and high power utilization are becoming more prevalent in the literature as understanding of their benefits increase.
From equivalent circuits, we find that the low-frequency buck cell does not affect the output inductor voltage, which has the same waveform and value as that of the conventional buck converter. That is, the voltage across the output inductor is Uin − Uo when the switch is on, and is −Uo when the switch is off. The voltage and current waveforms of DF buck in one low frequency cycle T sl are shown in Fig. 5, where M = 4. In the conduction mode of low-frequency switch, the
In contrast, the negative inductor that is presented here is based on modifying the magnetic flux linkage in a physical inductor, and is closer in principle to recently reported active magnetic metamaterials  or tunable inductors [9–12]. In the magnetic metamaterial , a current is induced in an input loop by an applied time-varying magnetic field, and this current is amplified, inverted, and applied to a parallel output loop a short distance away. By stacking cells of this sort, a metamaterial can be realized that exhibits an induced magnetic dipole moment density with opposite polarity to a conventional magnetic material. In a similar way, the device described here senses the current into an inductor, then amplifies the current and applies an opposing time-varying magnetic flux via a second inductor magnetically coupled to the first. If the gain is sufficiently large, the driven response can overcome the natural response of the inductor, leading to negative inductance values. Pehlke et al.  introduced a high-Q tunable inductorbased on a similar principle, and tunable inductors using this idea have been discussed by a number of authors [9–12]. However, these authors do not discuss the possibility of achieving negative inductance values.
The technique explored in this thesis is inductive coupling interconnect specifically over a short length transmission line. The application of this technique can be in high speed communication line between processor and a memory on the same circuit board. In LCI, two spiral inductors are stacked on top of each other with limited spacing between the inductors. The transformer works on the principle of applying current through the primary inductor, which would generate a differential voltage pulse on the secondary inductor. The challenge is in producing large enough output voltage pulse to be detectable by the receiver after going through a lossy transmission line and a second transformer without sacrificing power. The size of the voltage pulse depends on the coupling coefficient of the transformer and the rate of change in current being applied at the transmitter.
The activeinductor has been implemented in this design which performs the same function as passive inductors. Activeinductor is a combination of CMOS transistors. To design a low noise amplifier it has a fewer difficulty but it has higher flexibility to get the input and output matching, easy to design the layout and it does not have the magnetic field. For this design it does not used the real activeinductor as main function but change it with transistor that perform the same function with activeinductor. The advantages by using activeinductor are:
Abstract: One of the most important features of the Active Inductors (AIs) is their input equivalent resistance, namely series-loss resistance, which should be low enough to have a high Quality Factor (QF). Most of the previous methods by this goal did not yield a high enough QF. This paper presents a new method, namely applying an RC feedback, to cancel series-loss resistance entirely. As the RC feedback cancels series-loss resistance, it enhances the Self-Resonant Frequency (SRF) as well. The SRF of the AI has a range as high as 0.25-12.5 GHz. Compared to the previous reports, the QF has been improved by applying the RC feedback. The structure is such that the QF can be adjusted independent of the SRF. For example, a very high quality factor of 13159 at the frequency of 6.6 GHz with a 2.2 nH inductance is obtained, while noise voltage and power dissipation are less than 4.6 nV Hz and 4 mW, respectively. The AI is designed and simulated using 90 nm CMOS process and 1.2 V power supply. To the best of authors’ knowledge, this is the first time an RC feedback has been implemented to cancel series-loss resistance.
Abstract — This paper proposes a new high step-up DC–DC converter designed especially for regulating the dc interface between various micro sources and a dc–ac inverter to electricity grid. The need of Electricity increases the power demand where the power demand met by the conventional sources of energy has some disadvantage of pollution, this disadvantage can be decreased by the use of the Renewable energy sources like Fuel Cell and available solar energy. The figuration of the proposed converter is a quadratic boost converter with the coupled inductor in the second boost converter. The converter achieves high step-up voltage gain with appropriate duty ratio and low voltage stress on the power switch. Additionally, the energy stored in the leakage inductor of the coupled inductor can be recycled to the output capacitor. The inverter is switched with SPWM techniques used to reduce the harmonics and to achieve high-voltage, high-power capability but switching losses are increased because of increased device count. Switching losses can be reduced by Soft switching techniques. To verify the performance of the proposed converter, a 280-W prototype sample is implemented with an input voltage range of 20–40 V and an output voltage of up to 400 V. The upmost efficiency of 93.3% is reached with high-line input; on the other hand, the full-load efficiency remains at 89.3% during low-line input.
In many power factor correction applications, the power level can reach maximum value and sometimes the input voltage also will be too high. For high power and high voltage applications the inductor volume and weight is the major concern of the conventional boost converter. In this paper the two inductor boost converter is adopted which uses smaller inductors yielding high power density. This paper deals with the simulation of Fuzzy Logic based two inductor boost converter system. Fuzzy Logic controller is designed in MATLAB environment for the closed loop control model. Simulation results of converter for closed loop control strategy with both PI and fuzzy logic control techniques are discussed and compared.
A diode and capacitor-based passive-clamp circuit is shown in Fig. 2. In this clamp circuit, the clamp capacitor (Cc) is discharged to the output through the secondary side inductor (L2) of the coupled-inductor boost converter. However, the clamp diode (Dc), in this circuit, is in series with the coupled inductor. Therefore, it’s not only the leakage inductance current, but the total coupled-inductor current, which flows through the clamp diode (Dc). This causes large losses in the clamp diode. The clamp diode needs to be rated for the entire large power processed by the coupled-inductor boost converter. This can make the converter operation inefficient for the higher power applications. Furthermore, in this clamp circuit, to take the advantages of the reduced switch voltage stress feature of the coupled-inductor boost converter, the clamp capacitor has to be considerably large, capable of
 Q. Liu, L. Peng, Y. Kang, S. Tang, D. Wu, and Y. Qi, “A novel design and optimization method of an LCL filter for a shunt active power filter,” IEEE Trans. Ind. Electron., vol. 61, no. 8, pp. 4000–4010, Aug. 2014.
Fuel cell stacks and photovoltaic panels generate low DC voltages and these voltages need to be boosted before converted to AC voltage. Therefore, high step-up ratio DC-DC converters are preferred in renewable energy systems. A new topology to boost the input voltage to desired levels with low duty ratios, utilizing coupled inductor and to achieve high step-up voltage gain with an appropriate duty ratio have been proposed , . In addition, a passive clamp circuit reduces the voltage stresses on the main switch and Output diode; therefore low resistance RDS (ON) for the main switch can be adapted to reduce conduction loss.
In this paper, a new structure is proposed, which consists of an impedance network similar to Z-source converter, an H-bridge switching circuit similar to Z-H converter and a series of mirrored switched inductor cells. The proposed structure can work in both buck and boost operating modes. In the proposed topology, the voltage conversion ratio can be adjusted by changing the number of switched inductor cells; the diode before LC network is eliminated; due to Z-H structutre there is no ST switching state; and due to the symmetric switched-inductor cells, the proposed converter can be easily developed for ac-ac applications. One main difference between ac-ac converter of Z-H type and Z- source type is that the output voltage of Z-H type has sinusoidal waveform and this resolves the need for additional filter. The performance of the proposed buck- boost converter in dc-dc conversion, with detailed analysis of the equations of voltages, currents and voltage gain, for cells, is presented. Finally, in order to check the accurate performance of the proposed converter, the simulation results of two-cell converter are illustrated in PSCAD/EMTDC software.