Design of 0.5 V voltage-combiner based OTA with 60 dB gain 250 kHz UGB in CMOS

A gain enhancement technique for a pseudo differential OTA based on voltage combiner, suitable for sub-1 V supply is presented in this letter. The proposed technique uses a G _m boosted voltage combiner. Unlike the typical voltage combiner which has an approximated gain of \(2\,\frac{{\text{V}}}{{\text{V}}}\), this voltage combiner can produce gain more than \(5\,\frac{{\text{V}}}{{\text{V}}}\). So it help us achieve nearly 60 dB DC gain with 250 kHz UGB for the pseudo differential OTA at a capacitive load of 10 pF. Power dissipation is very low i.e. 716 nW at supply of 0.5 V. So as to facilitate maximum swing at 0.5 V supply and lower the power consumption, MOS transistors are biased in weak/moderate inversion. The OTA is designed in standard 45 nm CMOS process. Phase margin of is more than \(55^{\circ }\) for a typical load of 10 pF. The input referred noise is \(150\,\upmu {\text{V}}{/}\sqrt{{\text{Hz}}}\) at 10 Hz and slew rate \(0.02\,{\text{V}}{/}\upmu{\text{s}}\) for 10 pF load.     

Functionalized Multiwalled Carbon Nanotube Electrochemical Sensor for Determination of Anticancer Drug Flutamide

An electrochemical sensor based on functionalized multiwalled carbon nanotubes (MWCNT_f) has been developed and applied for determination of anticancer drug flutamide in pharmaceutical and artificial urine samples. The electrode was prepared by modifying a glassy carbon electrode with MWCNT_f, denoted herein as MWCNT_f/GCE. The MWCNT_f/GCE electrode exhibited high catalytic activity, high sensitivity, and high stability and was applicable over a wide concentration range for flutamide. The effects of the scan rate, pH, and nature of the electrolyte on the electrochemical behavior of flutamide on the MWCNT_f/GCE were investigated. The results showed that this electrode presented the best square-wave voltammetric response to flutamide in Britton–Robinson buffer solution at pH 5.0 at frequency of 50 Hz and amplitude of 0.06 V. The proposed sensor presents a wide linear response range from concentration of 0.1 μmol L^?1 up to 1000 μmol L^?1 (or 27.6 μg L^?1 up to 0.27 g L^?1), with limit of detection, limit of quantification, and sensitivity of 0.03 μmol L^?1, 0.1 μmol L^?1, and 0.30 μA μmol^?1 L, respectively. The MWCNT_f/GCE electrode was successfully applied for determination of flutamide in pharmaceutical formulations and artificial urine samples, giving results in agreement with those obtained by a comparative method described in literature. A paired Student’s t-test revealed no statistical difference between the reference and proposed method at 95% confidence level. The average recovery for fortified samples was 101 ± 1%.     

High-voltage MIS-gated GaN transistors

Transistors with a high electron mobility based on AlGaN/GaN epitaxial heterostructures are promising component types for creating high-power electronic devices of the next generation. This is due both to a high charge-carrier mobility in the transistor channel and a high electric durability of the material making it possible to achieve high breakdown voltages. For use in power switching devices, normally off GaN transistors operating in the enrichment mode are required. To create normally off GaN transistors, the subgate region on the basis of p-GaN doped with magnesium is more often used. However, optimization of the p-GaN epitaxial-layer thickness and doping level makes it possible to achieve a threshold voltage close to V _th = +2 V for the on-mode of GaN transistors. In this study, it is shown that the use of a subgate MIS (metal–insulator–semiconductor) structure involved in p-GaN transistors results in an increase in the threshold voltage for the on-mode to V _th = +6.8 V, which depends on the subgate-insulator thickness in a wide range. In addition, it is established that the use of the MIS structure results in a decrease in the initial transistor current and the gate current in the on mode, which enables us to decrease the energy losses when controlling powerful GaN transistors.     

Tuning the Electronic Properties of Graphene Oxide Nanoribbons Through Different Oxygen Doping Configurations

The electronic properties of armchair graphene oxide nanoribbons (AGONRs) with different doped oxygen configurations are studied based on density functional theory using first principle calculations. The electronic properties of the AGONRs are tuned by different oxygen configurations for top edges, center, bottom edges and fifth width. The AGONRs for top-edge O doping configuration are indirect band gap semiconductors with an energy gap of 1.268 eV involving hybridization among C-2p and O-2s, 2p electrons and electrical conductivity of oxygen atoms. The center and bottom edges are direct band gap semiconductors with 1.317 eV and 1.151 eV, respectively. The valence band is contributed from C-2p, O-2p and H-1s for top-edge O doping. The electronic properties of AGONRs are changed due to localization in ?2.94 eV of O-2p states. The center O-doped AGONRs are n-type semiconductors with Fermi levels near the conduction band bottom. This is due to hybridization among C-2s, 2p and O-2p electrons. However, bottom-edge O-doped AGONRs are p-type semiconductors, due to the electrical conductivity of oxygen atoms. The fifth-width O-doped AGONRs are indirect band gap semiconductors with an energy gap of 0.375 eV. The projected density of states shows that the localization and hybridization between C-2 s, 2p, O-2p and H-1s electronic states are rising in the conduction band and valence band from the projected density of states. The localization is induced by O-2p electronic states at a Fermi level.     

Simulation of Electronic Center Formation by Irradiation in Silicon Crystals

We present the results of a study on localized electronic centers formed in crystals by external influences (impurity introduction and irradiation). The main aim is to determine the nature of these centers in the forbidden gap of the energy states of the crystal lattice. For the case of semiconductors, silicon (Si) was applied as model material to determine the energy levels and concentration of radiation defects for application to both doped and other materials. This method relies on solving the appropriate equation describing the variation of the charge carrier concentration as a function of temperature n(T) for silicon crystals with two different energy levels and for a large set of N ₁, N ₂ (concentrations of electronic centers at each level), and n values. A total of almost 500 such combinations were found. For silicon, energy level values of ε ₁ = 0.22 eV and ε ₂ = 0.34 eV were used for the forbidden gap (with corresponding slopes determined from experimental temperature-dependent Hall-effect measurements) and compared with photoconductivity spectra. Additionally, it was shown that, for particular correlations among N ₁, N ₂, and n, curve slopes of ε ₁/2 = 0.11 eV, ε ₂/2 = 0.17 eV, and α = 1/2(ε ₁ + ε ₂) = 0.28 eV also apply. Comparison between experimental results for irradiation of silicon crystals by 3.5-MeV energy electrons and Co⁶⁰ γ-quanta revealed that the n(T) curve slopes do not always coincide with the actual energy levels (electronic centers).     

Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V _th = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V _th = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.     

Good Thermal Stability,High Permittivity,Low Dielectric Loss and Chemical Compatibility with Silver Electrodes of Low-Fired BaTiO<Subscript>3</Subscript>–Bi(Cu<Subscript>0.75</Subscript>W<Subscript>0.25</Subscript>)O<Subscript>3</Subscript> Ceramics

(1 ? x)BaTiO₃–xBi(Cu_0.75W_0.25)O₃ [(1 ? x)BT–xBCW, 0 ≤ x ≤ 0.04] perovskite solid solutions ceramics of an X8R-type multilayer ceramic capacitor with a low sintering temperature (900°C) were synthesized by a conventional solid state reaction technique. Raman spectra and x-ray diffraction analysis demonstrated that a systematically structural evolution from a tetragonal phase to a pseudo-cubic phase appeared near 0.03 < x < 0.04. X-ray photoelectron analysis confirmed the existence of Cu⁺/Cu²⁺ mixed-valent structure in 0.96BT–0.04BCW ceramics. 0.96BT–0.04BCW ceramics sintered at 900°C showed excellent temperature stability of permittivity (Δε/ε _25°C ≤ ±15%) and retained good dielectric properties (relative permittivity ～1450 and dielectric loss ≤2%) over a wide temperature range from 25°C to 150°C at 1 MHz. Especially, 0.96BT–0.04BCW dielectrics have good compatibility with silver powders. Dielectric properties and electrode compatibility suggest that the developed materials can be used in low temperature co-fired multilayer capacitor applications.     

Characterization of Double-Junction GaAsP Two-Color LED Structure

The structural, optical, electrical and electrical–optical properties of a double-junction GaAsP light-emitting diode (LED) structure grown on a GaP (100) substrate by using a molecular beam epitaxy technique were investigated. The p–n junction layers of GaAs_1?xP_x and GaAs_1?yP_y, which form the double-junction LED structure, were grown with two different P/As ratios. High-resolution x-ray diffraction (HRXRD), photoluminescence (PL), and current–voltage (I–V) measurements were used to investigate the structural, optical and electrical properties of the sample. Alloy composition values (x, y) and some crystal structure parameters were determined using HRXRD measurements. The phosphorus compositions of the first and second junctions were found to be 63.120% and 82.040%, respectively. Using PL emission peak positions at room temperature, the band gap energies (E_g) of the first and second junctions were found to be 1.867 eV and 2.098 eV, respectively. In addition, the alloy compositions were calculated by Vegard’s law using PL measurements. The turn-on voltage (V_on) and series resistance (R_s) of the device were obtained from the I–V measurements to be 4.548 V and 119 Ω, respectively. It was observed that the LED device emitted in the red (664.020 nm) and yellow (591.325 nm) color regions.     

Green Synthesis of Ag-Cu Nanoalloys Using <Emphasis Type="Italic">Opuntia ficus</Emphasis>-<Emphasis Type="Italic">indica</Emphasis>

Bimetallic Ag/Cu nanoparticles have been obtained by green synthesis using Opuntia ficus-indica plant extract. Two synthesis methods were applied to obtain nanoparticles with core–shell and Janus morphologies by reversing the order of precursors. Transmission electronic microscopy revealed size of 10 nm and 20 nm for the core–shell and Janus nanoparticles, respectively. Other small particles with size of up to 2 nm were also observed. Absorption bands attributed to surface plasmon resonance were detected at 440 nm and 500 nm for the core–shell and Janus nanoparticles, respectively. Density functional theory predicted a breathing mode type (BMT) located at low wavenumber due to small, low-energy clusters of (AgCu) _n with n = 2 to 9, showing a certain correlation with the experimental one (at 220 cm^?1). The dependence of the BMT on the number of atoms constituting the cluster is also studied.     

Improvement in Thermoelectric Performance of SnS Due to Electronic Structure Modification Under Biaxial Strain

Ab-initio calculations using the full potential linearized augmented plane-wave technique and the semi-classical Boltzmann theory are used to study thermoelectric properties of unstrained SnS and at 1%, 2% and 3% applied biaxial tensile (BT) strain. The studies are carried out at 800 K for p-type and n-type carriers. For an increase in BT strain, lattice constants of SnS change causing changes in the band structure and increase in the band gap which in turn modifies thermoelectric coefficients. In the case of unstrained SnS, the maximum thermopower (S) obtained is 426 μV/K at carrier concentration 5.40?×?10¹⁸ cm^?3 for p-type carriers and 435 μV/K at carrier concentration 1.68?×?10¹⁸ cm^?3 for n-type carriers. At 3% applied BT strain, S is increased to 696 μV/K at carrier concentration 4.61?×?10¹⁷ cm^?3 for p-type carriers and 624 μV/K at carrier concentration 3.21?×?10¹⁷ cm^?3 for n-type carriers. The power factor (PF) increases?～?2 times at 3% BT strain as compared to unstrained SnS, and it is 6.20 mW K^?2 m^?1 for p-type carriers. For n-type carriers, PF at 3% applied BT is slightly less than the PF for unstrained SnS, which is 6.81 mW K^?2 m^?1. For both types of carriers, the figure of merit (ZT) is found to be?～?1.5 for unstrained SnS. For p-type carriers ZT is enhanced 1.4 times at 3% applied BT strain as compared to that of unstrained SnS. However, for n-type carriers, ZT does not change drastically with increase in BT strain.     

Optical Properties of K<Subscript>2</Subscript>O-Li<Subscript>2</Subscript>O-WO<Subscript>3</Subscript>-B<Subscript>2</Subscript>O<Subscript>3</Subscript> Glasses: Evidence of Mixed Alkali Effect

Glass with compositions xK₂O-(30 ? x)Li₂O-10WO₃-60B₂O₃ for 0 ≤ x ≤ 30 mol.% have been prepared using the normal melt quenching technique. The optical reflection and absorption spectra were recorded at room temperature in the wavelength range 300–800 nm. From the absorption edge studies, the values of the optical band gap (E _opt) and Urbach energy (ΔE) have been evaluated. The values of E _opt and ΔE vary non-linearly with composition parameter, showing the mixed alkali effect. The dispersion of the refractive index is discussed in terms of the single oscillator Wemple Di-Domenico model.     

Study of RF transistor with submicron T-shaped gate fabricated by nanoimprint lithography

The results devoted to the development of a method for creating an RF transistor, in which a T-shaped gate is formed by nanoimprint lithography, are presented. The characteristics of GaAs p-HEMT transistors have been studied. The developed transistor has a gate “foot” length of the order of 250 nm and a maximum transconductance of more than 350 mS/mm. The maximum frequency of current amplification f _t is 40 GHz at the drain-source voltage V _DS = 1.4 V and the maximum frequency of the power gain f _max is 50 GHz at V _DS = 3 V.     

Transport Properties of CuInTe<Subscript>2</Subscript> Thin Films Obtained by the Electrochemical Route

CuInTe₂ (CIT) thin films were potentiostatically electrodeposited onto cadmium sulfide thin films coated on fluorine doped tin oxide (FTO) glass in an aqueous bath at 75°C by the standard three-electrode system at ??0.7 V and ??0.8 V, with respect to an Ag/AgCl reference electrode. The electrodeposited layers were heat treated at?～?80°C in air ambient for 60 min. X-ray diffraction pattern and Raman analysis confirmed the formation of chalcopyrite CIT thin films upon heat treatment. The optical band gap of heat treated CIT films was found to be?～?1.0 eV and 0.95 eV deposited at ??0.7 V and ??0.8 V, respectively. Compact and good adhesive growth of CIT layers onto CdS coated FTO substrates is confirmed by field emission scanning electron microscopy. The current density–voltage (J–V) and capacitance–voltage (C–V) measurement was studied to understand the electronic quality of material for development of CIT layers for solar cell applications. The current density was found to be increased by two orders of magnitude upon low-temperature heat treatment. The capacitance–voltage measurement showed sharp depletion and accumulation region. The built in potential was found to be ～?60 mV and 145 mV in the as-deposited samples, deposited at ??0.7 V and ??0.8 V, respectively, whereas upon heat treatment it shifted to 159 mV and 210 mV. The capacitance of the CIT films was found to be a function of applied bias and increased with increasing the bias voltage. The depletion width of the heat treated sample was found to be?～?20 nm and 200 nm for the sample deposited at ??0.7 V and ??0.8 V, respectively. Thus, the sample deposited at ??0.8 V shows optimum electronic properties and is found to be suitable for opto-electronic applications.     

Analysis of a high frequency and wide bandwidth active polyphase filter based on CMOS inverters

An active polyphase filter capable of high frequency quadrature signal generation has been analyzed. The resistors of the classical passive polyphase filter have been replaced by transconductors, CMOS inverters (F. Tillman and H. Sjöland, Proceedings of the Norchip Conference (pp. 12–15), Nov. 2005; Analog Integrated Circuits and Signal Processing, 50(1) 7–12, 2007). A three-stage 0.13 μm CMOS active polyphase filter has been designed. Simulations with a differential input signal show a quadrature error less than 1° for the full stable input voltage range for frequencies from 6 GHz to 14 GHz. Phase errors in the differential input signal are suppressed at least three times at the output. Corner simulations at 10 GHz show a maximum phase error of 3° with both n- and pMOS slow, in all other cases the error is less than 0.75°. The three-stage filter consumes 34 mA from a 1.2 V supply. To investigate the robustness of the filter to changes in inverter delay, an inverter model was implemented in Verilog-A. Linear c _in and g _in were used, whereas g _m , c _out , and g _out were non-linear. It was found that the filter could tolerate substantial delays. Up to 40° phase shift resulted in less than 1.5° quadrature phase error at the output.     

Crystalline SiN<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Ultrathin Films Grown on AlGaN/GaN Using <Emphasis Type="Italic">In Situ</Emphasis> Metalorganic Chemical Vapor Deposition

Surface passivation by SiN _x films is indispensable for high-power operation of AlGaN/GaN heterojunction field-effect transistors (HFETs) since it can effectively suppress collapse in the drain current. So far, the plasma-enhanced chemical vapor deposition technique has been used for the SiN _x deposition; however, possible damage induced by the plasma processing may affect direct-current performance or reliability. In this paper, we present subsequent deposition of SiN _x ultrathin films on AlGaN/GaN in the same metalorganic chemical vapor deposition reactor. It is experimentally found that this in situ SiN _x passivation doubles the sheet carrier density at the AlGaN/GaN interface from that of the unpassivated sample. High-resolution cross-sectional transmission electron microscopy reveals that in situ SiN _x is crystallized on the AlGaN layer as island-like structures via the Stranski-Krastanov growth mode. The lattice constants of in situ SiN _x are estimated to be a ≈ 3.2 Å and c ≈ 2.4 Å, which are quite different from those of well-known Si₃N₄ crystal structures. First-principles calculation predicts that the crystal structure of in situ SiN _x is the defect wurtzite structure, which well explains the experimental results. The passivation technique using crystalline SiN _x films would be promising for high-power and high-frequency applications of AlGaN/GaN HFETs.     

On the Dielectric Study of Se<Subscript>80−<Emphasis Type="Italic">x</Emphasis></Subscript>Te<Subscript>20</Subscript>Pb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (<Emphasis Type="Italic">x</Emphasis> = 0, 1 and 2) Glasses

In the present paper, the dielectric parameters such as the dielectric constant ε′(ω), dielectric loss ε″(ω) and alternating current (ac) conductivity have been investigated for bulk amorphous chalcogenide Se_80?x Te₂₀Pb _x (x = 0, 1 and 2) glasses in the frequency range 10 Hz to 500 kHz and within the temperature range from 300 K to 320 K. Dielectric constant ε′(ω) and dielectric loss ε″(ω) are found to be highly frequency (ω) and temperature dependent, and this behavior is interpreted on the basis of Guintini’s theory of dielectric dispersion. The ac conductivity (σ _ac) is found to be temperature independent and obey the power law ω ^s , where s < 1 and decreases as temperature rises. The obtained results are discussed in terms of the correlation barrier hopping model proposed by Elliot. The composition dependence of the dielectric constant, dielectric loss and ac conductivity are also discussed and reported here.     

Current-Transport Mechanisms of the Al/(Bi<Subscript>2</Subscript>S<Subscript>3</Subscript>-PVA Nanocomposite)/p-Si Schottky Diodes in the Temperature Range Between 220 K and 380 K

In this research, bismuth sulfide nanostructures were prepared in the presence of polyvinyl alcohol (PVA) as a capping agent by an ultrasound-assisted method. The x-ray diffraction results show the crystalline phase of the sample and the mean crystalline size estimated by Debye–Scherer’s equation. The UV–Vis absorption spectrum show that the optical absorbance edge of Bi₂S₃ nanostructure was blue-shifted. The Fourier transform infrared spectra confirm the presence of PVA in the sample and transmission electron microscopy imaging shows that the structures are in nanoscale. The semi-logarithmic forward bias I–V plots have two distinct linear regimes for each temperature which are called low- and moderate-bias regions (LBR and MBR). In order to effectively interpret possible current-conduction/transport mechanisms, the reverse saturation current (I_o), ideality factor (n) and zero-bias barrier height (Φ_BO) were obtained from the slope and intercept of these plots and they were found to be a strong function of temperature and voltage. The high value of n even at high temperature and the increase of Φ_BO with increasing temperature for the two regions is clear evidence of the deviation from thermionic emission (TE) theory. Therefore, Φ_BO versus n and q/2kT plots were drawn to get evidence of the Gaussian distribution (GD) of the barrier height (BH) and they show a linear behavior. The mean values of BH (\( \bar{\Phi }_{\rm{BO}} \)) and standard deviation (σ_s) were also obtained from the intercepts and slopes of the Φ_BO versus q/2kT plots as 1.44 eV and 0.19 V for the LBR and 1.32 eV and 0.18 V for the MBR, respectively. After that, the values \( \bar{\Phi }_{\rm{BO}} \) and effective Richardson constant (A^*) were obtained as 1.29 eV and 267.6 A/(cm K)² for the LBR and 1.27 eV and 281.7 A/(cm K)² for the MBR, respectively. Such non-ideal I–V–T characteristics for the Al/(PVA-Bi₂S₃)/p-Si structure can be successfully explained by the single GD of BH for the LBR and MBR.     

Influence of Composition on the Thermoelectric Properties of Bi<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Sb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Thin Films

Bi_1?x Sb _x solid solutions have attracted much attention as promising thermoelectric (TE) materials for cooling devices at temperatures below ～200 K and as unique model materials for solid-state science because of a high sensitivity of their band structure to changes in composition, temperature, pressure, etc. Earlier, we revealed a non-monotonic behavior of the concentration dependences of TE properties for polycrystalline Bi_1?x Sb _x solid solutions and attributed these anomalies to percolation effects in the solid solution, transition to a gapless state, and to a semimetal–semiconductor transition. The goal of the present work is to find out whether the non-monotonic behavior of the concentration dependences of TE properties is observed in the thin film state as well. The objects of the study are Bi_1?x Sb _x thin films with thicknesses in the range d = 250–300 nm prepared by thermal evaporation of Bi_1?x Sb _x crystals (x = 0–0.09) onto mica substrates. It was shown that the anomalies in the dependence of the TE properties on Bi_1?x Sb _x crystal composition are reproduced in thin films.     

Theoretical Study of Electronic Structure and Thermoelectric Properties of Doped CuAlO<Subscript>2</Subscript>

The doping level dependence of thermoelectric properties of delafossite CuAlO₂ has been investigated in the constant scattering time (τ) approximation, starting from the first principles of electronic structure. In particular, the lattice parameters and the energy band structure were calculated using the total energy plane-wave pseudopotential method. It was found that the lattice parameters of CuAlO₂ are a = 2.802 Å and c = 16.704 Å, and the internal parameter is u = 0.1097. CuAlO₂ has an indirect band gap of 2.17 eV and a direct gap of 3.31 eV. The calculated energy band structures were then used to calculate the electrical transport coefficients of CuAlO₂. By considering the effects of doping level and temperature, it was found that the Seebeck coefficient S(T) increases with increasing acceptor doping (A _d) level. The values of S(T) in our experiments correspond to an A _d level at 0.262 eV, which is identified as the Fermi level of CuAlO₂. Based on our experimental Seebeck coefficient and the electrical conductivity, the constant relaxation time is estimated to be 1 × 10^?16 s. The power factor is large for a low A _d level and increases with temperature. It is suggested that delafossite CuAlO₂ can be considered as a promising thermoelectric oxide material at high doping and high temperature.     

A Low-Voltage and Low-Power 3-GHz CMOS LC VCO for S-Band Wireless Applications

A fully integrated 0.18- \(\upmu \hbox {m}\) CMOS LC-tank voltage-controlled oscillator (VCO) suitable for low-voltage and low-power S-band wireless applications is proposed in this paper. In order to meet the requirement of low voltage applications, a differential configuration with two cross-coupled pairs by adopting admittance-transforming technique is employed. By using forward-body-biased metal oxide semiconductor field effect transistors, the proposed VCO can operate at 0.4 V supply voltage. Despite the low power supply near threshold voltage, the VCO achieves wide tuning range by using a voltage-boosting circuit and the standard mode PMOS varactors in the proposed oscillator architecture. The simulation results show that the proposed VCO achieves phase noise of \(-\) 120.1 dBc/Hz at 1 MHz offset and 39.3 % tuning range while consuming only \(594~\upmu \hbox {W}\) in 0.4 V supply. Figure-of-merit with tuning range of the proposed VCO is \(-\) 192.1 dB at 3 GHz.