Sinusoidal frequency doubler and full-wave rectifier usingtranslinear current conveyor

A simple circuit design technique for realising both a sinusoidal frequency doubler and a full-wave rectifier, employing a translinear current conveyor and current mirrors as active circuit elements, is proposed. The implementation method uses the inherited translinear loop of the translinear current conveyor to perform frequency doubling and rectification. The performance of the scheme is demonstrated by PSPICE simulations     

Dual translinear sinusoidal frequency doubler and full-wave rectifier

In this article, an integrable circuit principle which can be employed to realize both a sinusoidal frequency doubler and a full-wave rectifier is presented. The realization method makes use of a dual translinear characteristic of bipolar junction transistors. Two implementation circuits are proposed and their performance are demonstrated by experimental results.     

Integrable CMOS sinusoidal frequency doubler and full-wave rectifier

A CMOS integrable circuit technique for the realization of both a sinusoidal frequency doubler and a full-wave rectifier is described in this paper. The realization method makes use of the characteristic of a simple CMOS class AB amplifier configuration. Simulation and experimental results demonstrating the circuit performance are also included.     

A novel full-wave rectifier/sinusoidal frequency doubler topology based on CFOAs

In this paper, a high-efficiency class-F power amplifier (PA) is designed using integration between a low voltage p-HEMT transistor and a miniaturized microstrip suppressing cell. It results in nth harmonic suppression and high power added efficiency (PAE) under low radio frequency (RF) input powers. The simulation is performed based on harmonic balance analysis. The proposed power amplifier is fabricated, and measurements results validated the simulations. The proposed power amplifier operates at 1.8 GHz with 100 MHz bandwidth and an average PAE of 71.1%, with very low drain voltage of 2 V. At fundamental frequency of 1.8 GHz, the maximum measured PAE is 73.5% at about 12 dBm RF input power. The maximum output power and gain are 23.4 and 17.5 dBm in RF input power ranges of 0–12 dBm, respectively. The fabricated class-F PA with such characteristics can be used for power amplifications in wireless transmitters such as 4G (4th generation)-LTE (long term evolution) communication systems.     

Accurate translinear sinusoidal frequency doubler

A new wideband sinusoidal frequency-doubling technique is described. The circuit uses matched properties of monolithic transistors to achieve a precise square-law characteristic and is fully integrable. Critical emitter-area matching is not required to achieve output accuracy. This improvement over previously reported circuits is achieved without increasing circuit complexity.     

CMOS sinusoidal oscillator based on current-controlled current conveyors

A new realisation of a CMOS single resistance current-controlled current mode oscillator using active grounded resistances is described. A prototype has been realised in 0.8 /spl mu/m CMOS technology from AMS. Measurement results confirm oscillation over 10 MHz, low output distortion and wide tuning range.     

Sinusoidal frequency doubler

A translinear circuit is described that can perform exact frequency doubling, free of any d.c. component and with linear amplitude transfer. The basic circuit consists of matched-transistor monolithic arrays. Theory and circuit operation with results are given.     

High frequency current conveyor precision full-wave rectifier

The design of a precision full-wave rectifier using current conveyors is reported. The design uses a voltage reference circuit to clad the voltage excursions at the output of the rectifier during the zero crossings, which ensures that the usual large signal distortion associated with classical precision rectifiers is avoided. Measured rectifier performance using a 100 MHz current conveyor demonstrates good rectifier integrity at an operating frequency of 30 MHz     

New simple square-rooting circuits based on translinear current conveyors

Two new square-rooting circuits, based on second-generation current-controlled current conveyors (CCCIIs), are presented. The first square-rooting circuit consists of two CCCIIs, one current-controlled resistor and two grounded resistors. The input signal of the first circuit is a voltage, and output is the voltage proportional to the square root of input voltage. The second one consists of two CCCIIs and a current-controlled resistor. In the second circuit, the input signal is a current, and output is the current proportional to the square root of input current. Each circuit realizes by using a current-mode technique; hence the proposed square-rooting circuits are simple circuitry, wide dynamic range and wide bandwidth. The proposed square-rooting circuits were confirmed by using PSPICE simulation.     

Quadrature oscillator and universal filter based on translinear current conveyors

This paper presents quadrature oscillator and universal filter based on translinear current conveyors. The proposed circuit can realize as a quadrature oscillator or a universal filter without changing the circuit topology. When it works as a quadrature oscillator, four quadrature current outputs and two quadrature voltage outputs can be obtained. The condition and frequency of oscillation of oscillator can be controlled orthogonally and electronically. When it works as a universal filter, low-pass, band-pass, high-stop, band-stop, and all-pass filtering functions can be obtained simultaneously. The natural frequency and quality factor of filters can be controlled orthogonally and electronically. The proposed topology is simulated using PSPICE simulators and experimental results are also used to confirm workability of new circuit.     

Current controlled oscillator based on translinear conveyors

A current controlled oscillator based on translinear current conveyors is presented. The oscillation frequency can be varied proportionally to the bias current. The oscillator uses two CCCII's, and two grounded capacitors. SPICE simulation results agree with the theory     

Current controlled bandpass filter based on translinear conveyors

A new concept to take advantage of the parasitic resistance that appears on port X of the second-generation current conveyors is introduced. This parasitic resistance, which is controllable in current, leads to the definition of the second generation current controlled conveyors (CCCII). A current controlled bandpass filter, operating in the current mode, is also described. It uses only two CCCII's and two capacitors. Its central frequency can be adjusted by acting on the bias current of the conveyors. SPICE simulation results, in agreement with theory, are given for central frequencies around 30 MHz     

Electronically tunable multiphase sinusoidal oscillator using translinear current conveyors

A new electronically tunable current-mode multiphase sinusoidal oscillator based on translinear current conveyors is presented. The proposed oscillator circuit, which employs only one translinear current conveyor and one grounded capacitor for each phase, can generate arbitrary N output current equal-amplitude signals that are equally spaced in phase (N being even or odd), all at high output impedance terminals. The frequency of oscillation and the condition of oscillation can be controlled electronically and independently through the bias current of the translinear current conveyor. The proposed structure also has simple circuitry, low-component count, and is highly suitable for integrated circuit implementation. The theoretical results were verified by PSPICE simulation. In addition, the modification of the N sinusoidal oscillators to construct a programmable multiphase oscillator is also discussed.     

Voltage-mode full-wave rectifier based on DXCCII

The paper deals with the design and performance analyses of a current conveyor based voltage-mode full-wave rectifier. In the structure of the proposed non-linear circuit the second-generation current conveyor and dual-X current conveyor have been used as active elements. In the circuit the current sourcing scheme of the diodes is used to enable high-frequency signal processing. Except the active elements and only two rectifying diodes, other two resistors are required, generally operating as simple voltage-to-current and current-to-voltage converters. Using the CMOS implementation of the active elements, the performance of the rectifier was analyzed by evaluating the frequency dependent RMS error and DC transient value for different values of input voltage magnitudes. Furthermore, using readily available integrated circuits, the performance of the proposed structure has also been verified by experimental measurements that show the feasibility of the voltage-mode full-wave rectifier.     

Current-tunable current-mode multifunction filter based on dual-output current-controlled conveyors

In this paper, a current-tunable current-mode multifunction filter with two inputs and two outputs employing only four dual-output current-controlled conveyors (DO-CCCIIs) and two grounded capacitors is proposed. By appropriately connecting the input and output terminals, the proposed circuit can provide lowpass, bandpass, highpass, bandstop and allpass current responses. The filter also offers an independent electronic control of the natural frequency (ω_o) and the quality factor (Q) through adjusting the bias currents of the DO-CCCIIs. No critical matching conditions are imposed for realizing all the filter responses, and all the incremental parameter sensitivities are low. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

A full-wave rectifier using a current conveyor and current mirrors

The realization of a full-wave rectifier using a current conveyor and current mirrors is presented. The proposed rectifier is composed of a voltage-to-current converter, a current mode full-wave rectifier, and a current-to-voltage converter. A voltage input signal is changed into a current signal by the voltage-to-current converter. The current mode full-wave rectifier rectifies this current signal resulting in the current full-wave output signal that is converted into a voltage full-wave output signal by one grounded-resistor. The theory of operation is described. The simulation and experiment results are used to verify the theoretical prediction. Simulated results show that the proposed rectifier yields the minimum voltage rectification to 94µV. Experimental results demonstrate the performance of the proposed rectifier for 50mV_peak signal rectification.     

A new electronically tunable phase shifter employing current-controlled current conveyors

A new canonical current-mode (CM) filter topology is presented. It realizes first-order allpass filtering functions using two dual-output current-controlled current conveyors (DO-CCCII) and a single capacitor. The topology gives both inverting and non-inverting types of these filters. Owing to electronically tunability properties of the CCCII, phase response of the circuit can be controlled by an external control current. Realization of the allpass filter imposes no matching condition. All outputs of the filters exhibit high output impedances so that this property makes the circuits very attractive from the viewpoint of cascading in current mode. The theoretical results are verified with PSPICE simulations using a BJT realization of CCCII.     

Ultra-Low voltage-power DTMOS based full-wave rectifier

In this paper, dynamic threshold MOS (DTMOS) transistor based full-wave rectifier with ultra-low power consumption is presented. The proposed circuit composed of only four NMOS and seven DTMOS transistors when many rectifier circuits consist of passive circuit components such as diodes, resistors and active circuit elements. The layout occupies an active area of 24.6 µm × 65.01 µm and post-layout simulation results performed using Cadence Environment with 0.18 µm TSMC CMOS technology parameters. The rectifier circuit with ±0.2 V DC supply voltages can be operated up to approximately 500 MHz and consumes only 2.83 nW thanks to the DTMOS transistors.     

New electronically tunable current-mode universal biquad filter using translinear current conveyors

In this study, a new electronically tunable current-mode universal filter with two inputs and two outputs employing one translinear current conveyor, one translinear current conveyor with controlled current gain and two grounded capacitors is presented. The proposed circuit offers the following attractive features: realisation of low-pass, band-pass, high-pass, band-stop and all-pass current responses from the same configuration; employment of the minimum active and passive components; no requirement of component matching conditions; independent current-control of the parameters natural frequency (ω_o) and quality factor (Q); low active and passive sensitivities; and high impedance output. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

On the frequency limitations of the circuits based on second generation current conveyors

An equivalent circuit for the translinear implementation of the second generation current conveyors with positive or negative current transfer is given. This circuit takes into account the various parasitic elements of the conveyor which induce frequency limitations (gain values, poles of the transfers, and parasitic impedances). The methods allowing the determination of the values for these parasitic elements are indicated and discussed. The effect of each element on the frequency responses of the circuits using the conveyors are studied in every detail. The frequency behavior of two circuits are analyzed as examples: a voltage amplifier without feedback and two configurations for a second order biquad filter operating in current-mode. All the theoretical results of the analysis are well confirmed from SPICE simulations.