Quadrature Oscillator Research Articles

CCCIIs-Based First-Order All-Pass Filter and Quadrature Oscillators

This paper introduces a current-mode first-order all-pass filter (APF) and its application in quadrature oscillator (QO) based on CCCII. The proposed filter can provide inverting and noninverting all-pass functions with a same circuit topology, it uses two CCCIIs and one grounded capacitor. Moreover, the first-order all-pass filter was applied in current-mode sinusoidal quadrature oscillators with the design based on block diagrams. The introduced oscillators can provide four phase-quadrature signals which independently control the condition of oscillation (CO) and frequency of oscillation (FO). The proposed oscillators consist of three CCCIIs and two grounded capacitors. The proposed APF and QOs have high output impedance which can directly drive load without additional current buffer. In addition, they use only grounded capacitors which are very appropriate to future development into an integrated circuit. The results of PSPICE simulation program correspond to the theoretical analysis.

Cascadable and Tunable Analog Building Blocks Using EX-CCCII

A new cascadable voltage-input, current-output first-order all-pass filter and its applications in second-order filter and oscillator are presented. The proposed circuit employs a single active element namely extra-X current-controlled current conveyor (EX-CCCII) and only a single grounded capacitor. The circuit exhibits high input and high output impedances, so that the filter can be cascaded without additional buffers. The pole frequency is electronically tunable and the circuit requires no component matching constraints. Effects of nonidealities and parasitics are also discussed. As applications, a second-order transadmittance (TA)-mode all-pass filter and a quadrature oscillator are also realized using the proposed voltage-input, current-output first-order all-pass filter. These examples validate easy cascading feature of the proposed circuit. The validity of the proposed circuit is verified through PSPICE simulations using 0.25[Formula: see text][Formula: see text]m parameters with a supply voltage of [Formula: see text][Formula: see text]V.

Voltage-Mode and Current-Mode Resistorless Third-Order Quadrature Oscillator

This paper presents the realization of a resistorless third-order quadrature oscillator using two multiple-output current controlled current conveyor transconductance amplifiers (MO-CCCCTAs) and three grounded capacitors. The proposed circuit provides two quadrature voltage outputs, two high-impedance quadrature current outputs, and one high-impedance amplitude-controllable current output. The proposed oscillator satisfies the industrial requirement for amplifier and modulation signals and phase shift keying signals, when the input bias current of the second MO-CCCCTA is used as a modulating signal. Its oscillation condition and oscillation frequency can be adjusted independently by two different bias currents of MO-CCCCTAs. The structure of resistorless and only grounded capacitors suggests that the proposed oscillator can be easily implemented in an integrated circuit.

A Low Power Low Phase Noise Oscillator for MICS Transceivers.

A low-power, low-phase-noise quadrature oscillator for Medical Implantable Communications Service (MICS) transceivers is presented. The proposed quadrature oscillator generates 349~689 MHz I/Q (In-phase and Quadrature) signals covering the MICS band. The oscillator is based on a differential pair with positive feedback. Each delay cell consists of a few transistors enabling lower voltage operation. Since the oscillator is very sensitive to disturbances in the supply voltage and ground, a self-bias circuit for isolating the voltage disturbance is proposed to achieve bias voltages which can track the disturbances from the supply and ground. The oscillation frequency, which is controlled by the bias voltages, is less sensitive to the supply and ground noise, and a low phase noise is achieved. The chip is fabricated in the UMC (United Microelectronics Corporation) 0.18 μm CMOS (Complementary Metal Oxide Semiconductor) process; the core just occupies a 28.5 × 22 μm2 area. The measured phase noise is −108.45 dBc/Hz at a 1 MHz offset with a center frequency of 540 MHz. The gain of the oscillator is 0.309 MHz/mV with a control voltage from 0 V to 1.1 V. The circuit can work with a supply voltage as low as 1.2 V and the power consumption is only 0.46 mW at a 1.8 V supply voltage.

Compact electronically tunable quadrature oscillator using single voltage differencing gain amplifier (VDGA) and all grounded passive elements

This work deals with the design of a compact electronically tunable sinusoidal quadrature oscillator. The proposed quadrature oscillator is designed with a single voltage differencing gain amplifier (VDGA) and all the three grounded passive elements. Its oscillation condition and oscillation frequency can be tuned independently by means of the VDGA transconductance gains. The proposed oscillator also provides the explicit quadrature voltage outputs of almost equal magnitude and low active and passive sensitivity figures. The performance of the oscillator has been demonstrated by PSPICE simulations based on TSMC 0.35-$\mu $m CMOS technology.

All-Pass Filter Based Linear Voltage Controlled Quadrature Oscillator

A linear voltage controlled quadrature oscillator implemented from a first-order electronically tunable all-pass filter (ETAF) is presented. The active element is commercially available current feedback amplifier (AD844) in conjunction with the relatively new Multiplication Mode Current Conveyor (MMCC) device. Electronic tunability is obtained by the control node voltage (V) of the MMCC. Effects of the device nonidealities, namely, the parasitic capacitors and the roll-off poles of the port-transfer ratios of the device, are shown to be negligible, even though the usable high-frequency ranges are constrained by these imperfections. Subsequently the filter is looped with an electronically tunable integrator (ETI) to implement the quadrature oscillator (QO). Experimental responses on the voltage tunable phase of the filter and the linear-tuning law of the quadrature oscillator up to 9.9 MHz at low THD are verified by simulation and hardware tests.

Two New Single-Resistor-Controlled Quadrature Sinusoidal Oscillators using Current-Differencing-Buffered-Amplifiers

Two new single resistor–controlled quadrature oscillator (SRCQO) circuits using only two current differencing buffered amplifiers (CDBAs) as active elements and only three resistors and two capacitors, are presented. First proposed circuit uses all input terminals of the CDBA to exploit full capacity of the CDBAs, offers better sensitivities with respect to active parameters and has wide frequency range of operation. The second proposed circuit provides very good low frequency performance with respect to total harmonic distortion. Separate single resistors can control both oscillation condition and the oscillation frequency of the proposed quadrature oscillator circuits independently. PSPICE simulation results based upon commercially available AD844 ICs, to construct the CDBAs, are included which confirm the practical workability of the new proposed quadrature oscillator circuits.

Designing RF Ring Oscillator Using Current-Mode Technology

In this paper, a new method of designing RF ring oscillator using current-mode technology is presented. The current-mode low frequency oscillator theory is transferred to facilitate the design of RF ring oscillator. As an example, a current-mode RF quadrature ring oscillator (RFQRO) for $L$ -band wireless communication applications is presented. The current-mode RFQRO consists of two first-order all-pass filters, and it provides four quadrature RF sinusoidal outputs. The proposed current-mode RFQRO is verified with GlobalFoundries’ $0.18~\mu \text{m}$ 1P6M CMOS RF process. The simulated and measured results demonstrate that the proposed RFQRO works at 1.03 GHz, and its frequency tuning range is from 648.9 MHz to 1.17 GHz by adjusting the bias voltage from 0.62 to 1 V. The measured phase noise of the RFQRO is −105.5 dBc/Hz at 1 MHz offset, and it consumes 2.5 mW from 1 V supply voltage.

Electronically Tunable Quadrature Sinusoidal Oscillator with Equal Output Amplitudes during Frequency Tuning Process

A new configuration of voltage-mode quadrature sinusoidal oscillator is proposed. The proposed oscillator employs two voltage differencing current conveyors (VDCCs), two resistors, and two grounded capacitors. In this design, the use of multiple/dual output terminal active building block is not required. The tuning of frequency of oscillation (FO) can be done electronically by adjusting the bias current of active device without affecting condition of oscillation (CO). The electronic tuning can be done by controlling the bias current using a digital circuit. The amplitude of two sinusoidal outputs is equal when the frequency of oscillation is tuned. This makes the sinusoidal output voltages meet good total harmonic distortions (THD). Moreover, the proposed circuit can provide the sinusoidal output current with high impedance which is connected to external load or to another circuit without the use of buffer device. To confirm that the oscillator can generate the quadrature sinusoidal output signal, the experimental results using VDCC constructed from commercially available ICs are also included. The experimental results agree well with theoretical anticipation.

Voltage-Mode Third-Order Quadrature Sinusoidal Oscillator Using VDBAs

This paper presents a third-order quadrature sinusoidal oscillator (TOQSO) using two voltage differencing buffered amplifiers (VDBAs), three capacitors and a resistor. The new topology provides two quadrature voltage outputs. The condition of oscillation (CO) and frequency of oscillation (FO) are electronically independently controllable by the separate transconductance of the VDBAs. The workability of the proposed TOQSO is confirmed by SPICE (Version 16.5) simulation using Taiwan semiconductor manufacturing company (TSMC) 0.18 μm process parameters.

System simulations of a 1.5\xa0V SiGe 81\u201386\xa0GHz E-band transmitter

This paper presents simulation results for a sliding-IF SiGe E-band transmitter circuit for the 81–86 GHz E-band. The circuit was designed in a SiGe process with fT = 200 GHz and uses a supply of 1.5 V. The low supply voltage eliminates the need for a dedicated transmitter voltage regulator. The carrier generation is based on a 28 GHz quadrature voltage oscillator (QVCO). Upconversion to 84 GHz is performed by first mixing with the QVCO signals, converting the signal from baseband to 28 GHz, and then mixing it with the 56 GHz QVCO second harmonic, present at the emitter nodes of the QVCO core devices. The second mixer is connected to a three-stage power amplifier utilizing capacitive cross-coupling to increase the gain, providing a saturated output power of +14 dBm with a 1 dB output compression point of +11 dBm. E-band radio links using higher order modulation, e.g. 64 QAM, are sensitive to I/Q phase errors. The presented design is based on a 28 GHz QVCO, the lower frequency reducing the phase error due to mismatch in active and passive devices. The I/Q mismatch can be further reduced by adjusting varactors connected to each QVCO output. The analog performance of the transmitter is based on ADS Momentum models of all inductors and transformers, and layout parasitic extracted views of the active parts. For the simulations with a 16 QAM modulated baseband input signal, however, the Momentum models were replaced with lumped equivalent models to ease simulator convergence. Constellation diagrams and error vector magnitude (EVM) were calculated in MATLAB using data from transient simulations. The EVM dependency on QVCO phase noise, I/Q imbalance and PA compression has been analyzed. For an average output power of 7.5 dBm, the design achieves 7.2% EVM for a 16 QAM signal with 1 GHz bandwidth. The current consumption of the transmitter, including the PA, equals 131 mA from a 1.5 V supply.

A series‐coupled LC quadrature oscillator using phase/amplitude calibration

SummaryIn this paper, an analytic approach for the estimation of the phase and amplitude error in series coupled LC quadrature oscillator (SC‐QO) is proposed. The analysis results show that imbalances in source voltage of coupling transistor because of mismatches between LC tanks are the main source of the phase and amplitude error in this oscillator. For compensation of the phase and amplitude error, a phase and amplitude‐tunable series coupled quadrature oscillator is designed in this paper. A phase shift generation circuit, designed using an added coupling transistor, can control the coupling transistor source voltage. The phase and amplitude error can simply be controlled and removed by tuning the phase shifter, while this correction does not have undesirable impact on phase noise. In fact, the proposed SC‐QO generates a phase shift in the output current, which reduces the resonator phase shift (RPS) and improves phase noise. The phase and amplitude tunable SC‐QO is able to correct the phase error up to ±12°, while amplitude imbalances are reduced as well. To evaluate the proposed analysis, a 4.5‐GHz CMOS SC‐QO is simulated using the practical 0.18‐μm TSMC CMOS technology with a current consumption of 2 mA at 1.8‐V supply voltage. Copyright © 2016 John Wiley & Sons, Ltd.

DO-CCII/DO-DVCC Based Electronically Fine Tunable Quadrature Oscillators

In this paper, a new quadrature oscillator employing two dual output second-generation current conveyors (DO-CCIIs), two resistors and two grounded capacitors is proposed. The proposed quadrature oscillator has only resistors but no capacitors connected in series to [Formula: see text] terminals of the DO-CCIIs; thus, it can be operated at high frequencies. It can be tuned electronically by replacing dual output second-generation current controlled current conveyors instead of DO-CCIIs and removing both resistors. It can provide two output currents in opposite sign. Nevertheless, its resonance frequency can be simultaneously controlled by two resistors. Also, a dual output differential voltage current conveyor (DO-DVCC) based quadrature oscillator which employs a canonical number of only grounded passive components is proposed. A number of simulation results based on SPICE program and an experimental test result are included to exhibit performance, workability and effectiveness of the proposed quadrature oscillators.

Novel CMOS Current Inverting Differential Input Transconductance Amplifier and Its Application

This paper presents the complementary metal oxide semiconductor (CMOS) implementation of active building block, namely, current inverting differential input transconductance amplifier (CIDITA) along with its performance parameters. The detailed study of the proposed CMOS CIDITA has been incorporated. The presented study shows the good performance of CIDITA in terms of good bandwidth range, good linear range of input current, high accuracy and low operating voltage. A new circuit of single active element-based quadrature oscillator is further realized to explore the workability of CIDITA. The proposed circuit of quadrature oscillator employs two grounded capacitors, one resistor and single CIDITA. The proposed quadrature oscillator provides both quadrature current outputs and quadrature voltage outputs simultaneously. The frequency of oscillation of the proposed quadrature oscillator is electronically controllable. The possible practical realization of the CIDITA using commercially available ICs is also given. HSPICE simulation results using 0.18[Formula: see text][Formula: see text]m CMOS parameters are given to validate the proposed theory.

A Wideband Injection Locked Quadrature Clock Generation and Distribution Technique for an Energy-Proportional 16–32 Gb/s Optical Receiver in 28 nm FDSOI CMOS

We present a novel frequency tracking method that exploits the dynamics of injection locking in a quadrature ring oscillator to increase the effective locking range from 5% (7–7.4 GHz) to 90% (4–11 GHz). The quadrature phase error between I and Q phases of an injection locked ring oscillator is derived and shown to contain frequency error information, both inside and outside the locking range. This error is utilized to form a first-order frequency tracking quadrature locked loop (QLL). This loop generates accurate clock phases for a 4-channel parallel optical receiver using a forwarded clock at quarter-rate. The QLL drives an ILO at each channel without any repeaters for local quadrature clock generation. Each local ILO has deskew capability for phase alignment. The receiver maintains a constant energy-per-bit consumption across 16–32 Gb/s by adaptive body biasing in a 28 nm FDSOI technology.

A 2.4 GHz high-performance CMOS differential quadrature relaxation oscillator

In this paper, the effects that limit the performance of practical implementations of RC relaxation oscillators are investigated. The insights gained are used to suggest a topology for high-frequen...

5 GHz CMOS Quadrature VCO Using Trifilar-Transformer-Coupling Technology

A trifilar-transformer-coupling quadrature voltage-controlled oscillator (TTC-QVCO) with dual transformer- feedback technology is proposed. Compared to traditional QVCOs, the proposed TTC-QVCO provides an additional coupling path, and therefore achieves an improved quadrature phase accuracy, a lower phase noise and a wider tuning range. The TTC-QVCO, implemented in a 0.18- $\mu \text {m}$ CMOS technology, exhibits a frequency tuning range of 19.6% centered at 5.4 GHz and a power consumption of 5.4 mW from a 1.35 V supply voltage. The QVCO has a measured phase noise of −120.42 dBc/Hz at 1-MHz offset and quadrature phase error of less than 2° with a FoMT of 194.3 dB.

I/Q mismatch calibration of a transmitter using local quadrature oscillator

In this paper a calibration technique for I/Q mismatch of a transmitter is introduced. The calibration technique is based on the fact that all mismatches in I/Q paths can be modeled as the mismatch of the local oscillator quadrature outputs. Based on this fact, a simple tuning scheme for quadrature output of the oscillator is used to calibrate the mismatch of the I/Q transmitter. In addition to quadrature oscillator, gain mismatch of the I/Q paths and LO feedthorugh and leakage is calibrated by using a tunable linear Gm cell in the base band part. In order to demonstrate the proposed technique, a transmitter with 1.8GHz carrier frequency is designed with auxiliary blocks to extract and cancel out the I/Q mismatches. The simulation results in 0.18µm RFCMOS process show that the proposed technique can reduce amplitude of the image signal resulting from mismatches in I/Q paths about 18.5dB in the transmitter output.

Single DD-DXCCII based quadrature oscillator with simultaneous current and voltage outputs

In this paper, a versatile quadrature oscillator using single Differential Difference Second Generation Dual-X Current Conveyor (DD-DXCCII) as an active element, two grounded capacitors and three grounded resistors is presented. The proposed oscillator provides two current outputs and three voltage outputs in quadrature relationship simultaneously so named as versatile quadrature oscillator. The proposed versatile quadrature oscillator exhibits the feature of orthogonal control over the frequency of oscillation and condition of oscillation. Effects of non-idealities along with sensitivity analysis are also analyzed. The proposed circuit has low active and passive sensitivities. Parasitic study is further explored. The simulation results with 0.18μm CMOS process parameters using PSPICE are also given. Possible realization of proposed oscillator using AD-844 and LM13600 along with some simulation results are also given for completeness sake.

Low Voltage Mixed-mode Multi Phase Oscillator Using Single FDCCII

In this paper a new low voltage mixed-mode multiphase quadrature oscillator employing a single fully differential second generation current conveyor, two resistors and two grounded capacitors is proposed. The proposed circuit provides two quadrature voltage outputs and three quadrature current outputs simultaneously. In addition, the proposed circuit has been made load insensitive so that it is capable of providing high output impedance current outputs without using additional current followers. Moreover, the proposed circuit of load insensitive quadrature oscillator provides four phase current outputs and two voltage outputs, simultaneously. Non ideal study is also included. Both the proposed circuits enjoy low active and passive sensitivities. This paper further presents an active-C multiphase oscillator with a single FDCCII and two grounded capacitors. The proposed structures are suitable for low voltage applications. Simulation results using PSPICE program on cadence tool are included.