Quadrature Signal Generation Research Articles

A K-Band CMOS Quadrature Frequency Tripler Using Sub-Harmonic Mixer

A low-power frequency tripler is designed by using the sub-harmonic mixer configuration for K-band applications. The proposed circuit features quadrature signal generation, applicable to LO signal synthesis in millimeter-wave wireless transceivers. It achieves conversion gain of -5.7 dB at the output frequency of 21 GHz. Implemented in a 0.18 mum CMOS technology, the circuit consumes power of 7.5 mW with 1.5 V supply voltage. The entire die occupies an area of 1000times1050 mum2.

Fully Integrated Seven-Order Frequency-Range Quadrature Sinusoid Signal Generator

A compact wide-frequency-range quadrature sinusoid signal generator tailored to on-chip impedance spectroscopy instrumentation applications is described. Using a new hybrid structure, it provides seven orders of frequency-tuning range (1 mHz to 10 kHz) appropriate for impedance characterization of many sensor materials. The signal generator exhibits very accurate frequency tuning through digital control, and the new structure inherently guarantees good phase and amplitude matching between sine and cosine outputs across the supported frequency range. The circuit has been fabricated in a 0.5-mum CMOS process and occupies 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . It consumes only 60 muA with a 3-V supply. Measurements show that the phase mismatch is less than 0.8 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">deg</sup> and that the amplitude mismatch is less than 3%. The total harmonic distortion is below 0.6% over the seven-order frequency range.

10 GHz dual-conversion low-IF downconverter with microwave and analogue quadrature generators

A 10 GHz dual-conversion low-IF downconverter using 0.18-µm CMOS technology is demonstrated. The high-frequency quadrature RF and LO1 signals are generated by broadside-coupled quadrature couplers while a two-section polyphase filter is utilised for the low-frequency LO2 quadrature signal generation. As a result, the demonstrated downconverter achieves a conversion gain of 7 dB, IP1 dB of −16 dBm, IIP3 of −5 dBm and noise figure of 26 dB at a 1.8 V supply. The image-rejection ratio of the first/second image signal is 33/42 dB for IF frequency ranging from 10 to 60 MHz, respectively.

A wide band differentially switch-tuned CMOS monolithic quadrature VCO with a low Kvco and high linearity

A wide band, differentially switch-tuned CMOS monolithic LC–VCO is presented in this paper, as well as a frequency divider for high linearity, low Kvco quadrature signal generation. A linearity control logic is proposed. The Kvco linearity is improved to be lower than 17.68MHz/V. By using the proposed CML DFF, the operating frequency of the frequency divider is increased by 20% with a power consumption of 3.6mW. The proposed design has been fabricated and verified in a 0.18μm CMOS process. The QVCO is tuned in a combined way of continuous technology and 4bit binary switch capacitor array (SCA) discrete tuning technology. The measurement indicates that the QVCO has a 19.7% tuning range from 1.816 to 2.213GHz. The measured phase noise is −112.25dBc/Hz at 1MHz offset from the 1.819GHz carrier and draws a current of 4.0mA around at a 1.8V supply.

A low power 3–5 GHz CMOS UWB receiver front-end

A novel low power RF receiver front-end for 3–5 GHz UWB is presented. Designed in the 0.13 μm CMOS process, the direct conversion receiver features a wideband balun-coupled noise cancelling transconductance input stage, followed by quadrature passive mixers and transimpedance loading amplifiers. Measurement results show that the receiver achieves an input return loss below −8.5 dB across the 3.1–4.7 GHz frequency range, maximum voltage conversion gain of 27 dB, minimum noise figure of 4 dB, IIP3 of −11.5 dBm, and IIP2 of 33 dBm. Working under 1.2 V supply voltage, the receiver consumes total current of 18 mA including 10 mA by on-chip quadrature LO signal generation and buffer circuits. The chip area with pads is 1.1 × 1.5 mm2.

A 2 to 5 GHz-Band Self Frequency Dividing Quadrature Mixer Using Current Re-Use Configuration

A 2 to 5GHz-band self frequency dividing quadrature mixer utilizing current re-use configuration with small size and broad band operation is proposed for a direct conversion receiver and a low-IF receiver of cognitive radio. The proposed mixer operates at twice the LO frequency by directly using a static type flip-flop frequency divider as the LO switching circuit for quadrature signal generation. The current re-use configuration is realized because the dc current of the frequency divider and the RF common-emitter amplifier share the same current flow path. Simulations and experiments verify that the proposed mixer offers broad band operation, miniaturization, and low power consumption. The mixer IC fabricated by 0.35μm SiGe-BiCMOS technology achieved the conversion gain of 20.6dB, noise figure of 11.9dB and EVM for π/4-shift QPSK signal of 4.4% at 2.1GHz with power consumption of 15mW and size of 0.22×0.31mm2. For the confirmation of broad band operation, the characteristics of conversion gain and noise figure were measured at 5.2GHz. The proposed mixer could operate at 5.2GHz with enough conversion gain, but the noise figure was inferior to that of 2.1GHz. Therefore the further investigation and improvement about the noise figure will be needed for higher frequency.

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. Sjoland, 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.

A Double-Balanced Quadrature-Input Quadrature-Output Regenerative Frequency Divider for UWB Synthesizer Applications

This paper presents the design and analysis of a proposed double-balanced quadrature-input quadrature-output (QIQO) regenerative divider for ultra-wideband (UWB) synthesizer applications. By fully utilizing the quadrature phase outputs already existed in a quadrature voltage-controlled oscillator (QVCO) or any other quadrature signal generator (QSG), the proposed QIQO divider provides a mechanism to achieve an output IQ phase sequence that is inherently tracked with the input IQ phase sequence. Moreover, compared with conventional dividers, the QIQO divider provides not only smaller and better-matched input loading to the QSG but also improved quadrature phase accuracy, wider operation range, smaller third harmonics, and lower power consumption. Fabricated in a 0.18-mum CMOS process, the QIQO divider measures an image rejection of -62dBc with a frequency operation range of larger than 18.4% from 8.6 GHz to 10.34 GHz while consuming 7.2 mW at 0.9-V supply.

A 1 V 2.2 mW 7 GHz CMOS Quadrature VCO Using Current-Reuse and Cross-Coupled Transformer-Feedback Technology

A current-reused quadrature voltage-controlled oscillator (CR-QVCO) is proposed with the cross-coupled transformer-feedback technology for the quadrature signal generation. This CR-QVCO has the advantages of low-voltage/low-power operation with an adequate phase noise performance. A compact differential three-port transformer, in which two half-circle secondary coils are carefully designed to optimize the effective turn ratio and the coupling factor, is newly constructed to satisfy the need of signal coupling and to save the area consumption simultaneously. The quadrature oscillator providing a center frequency of 7.128 GHz for the ultrawideband (UWB) frequency synthesizer use is demonstrated in a 0.18 mum RF CMOS technology. The oscillator core dissipates 2.2 mW from a 1 V supply and occupies an area of 0.48 mm2. A tuning range of 330 MHz (with a maximum control voltage of 1.8 V) can be achieved to stand the frequency shift caused by the process variation. The measured phase noise is -111.2 dBc/Hz at 1 MHz offset from the center frequency. The IQ phase error shown is less than 2deg. The calculated figure-of-merit (FOM) is 184.8 dB.

Injection Locking in Concurrent Dual-Frequency Oscillators

In a separate paper, the authors show that a nonlinear active core with a fourth-order resonator can generate two stable independent frequencies simultaneously. In this paper, the effect of injecting two frequencies into such a concurrent dual-frequency oscillator is analyzed and experimentally verified. It is shown that, for weak injection, the effect of injection at one frequency is decoupled from the effect of injection at the other frequency. The differential equation describing the effect of injection at either of the two frequencies is similar to the Adler's injection-locking equation for single-frequency oscillators. A theoretical analysis for a linear array of coupled concurrent dual-frequency oscillators is provided. It is shown that a linear phase progression at both frequencies can be achieved independently by detuning the array's end elements. Dual-frequency quadrature signal generation using two coupled concurrent dual-frequency oscillators is also demonstrated. To verify the theoretical derivations, an integrated circuit in a 0.18-m SiGe BiCMOS process is designed and fabricated. Measurement results closely match the theoretical predictions. The application of concurrent coupled oscillator array in dual-frequency beam forming with steering capability is also demonstrated.

On-electrode autonomous current generator for multi-frequency EIT

The paper presents an autonomous programmable current generator module for multi-frequency EIT systems. The module incorporates all stages from the sine wave generation with frequency and amplitude tuning, D/A converter and filter, a high output resistance voltage-to-current converter to the associated digital communication and control. The paper presents in depth the original digital quadrature signal generator and the output current generator with a high resistance. The other main blocks of the design use current practice specifications, since recent technological solutions proposed in the literature were found appropriate. The proposed signal generator circuit, characterized by a very low complexity, is analyzed in its capacity to produce multiple accurate signals up to 1 MHz in frequency. The precision output current source uses a modified current conveyor of type CCII with a high output resistance and low distortion. The output current frequency spectrum and linearity parameters obtained in the simulations are also described. The simulation results indicate a good linearity and high output resistance with an acceptable output voltage swing. The calculated performance parameters are validated with simulations, and future work for the prototype fabrication of the IC is outlined.

A CMOS K-Band Quadrature Generator

This letter presents a K-band quadrature signal generator in a standard 0.13 mu m CMOS process. The quadrature generator operates from 18 to 21 GHz. A maximum output power of -3.7 dBm (per I or Q channel) is achieved, and the down converted signal suppression is >25 dB at the operating bandwidth. A measured sideband rejection ratio >30 dB is achieved from 19 to 21 GHz, with a peak of >40 dB at 19.5-20.5 GHz. The current consumption of the quadrature generator is 49-54 mA from a 2-2.5 V supply with an effective chip area of 0.51times 0.44 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . To the author's knowledge, this is the first demonstration of a K-band quadrature signal generator with high spectral purity and quadrature accuracy.

Design of Ka-band Monolithic Image Rejection Mixer

In this paper, a 30–40 GHz monolithic image rejection mixer is described. The mixer employs two drain LO injection mixer cells, which can perform well even with zero drain bias voltage. Also it employs Lange Coupler for RF quadrature signal generation. The mixer is fabricated by a commercial 0.18-μm pseudomorphic high electron-mobility transistor (pHEMT) process. It achieves image rejection ratio of more than 20.4 dB and conversion loss of less than 12.6 dB in the frequency range of 30 to 38 GHz.

A polyphase filter based on CMOS inverters

A new idea for generation of quadrature signals on chip is presented. The topology is based on a passive RC polyphase filter, where the resistive parts are made active by using inverters. The activ...

Generation of arbitrary quadrature signals using one dual-drive Modulator

Regardless of the number of constellation points, all quadrature-amplitude modulation (QAM) signals can be generated using a single dual-drive Mach-Zehnder modulator. When the general method is applied to quadrature-phase-shift-keying (QPSK) signals, three different QPSK transmitters are shown with drive signals having four, three, or two levels. The usage of only one dual-drive modulator greatly simplifies the design of QAM and QPSK transmitters.

Analysis of parasites by electrorotation.

The application of the AC electrokinetic technique of electrorotation for studying eukaryotic parasite transmission stages is reviewed. Electrorotation is a noninvasive technique that utilizes electrically energized microelectrode structures within micro-fluidic chambers to probe the physiological structure of micro-organisms. Application of the technique to the transmission life cycle stages of three separate genera of protozoan parasites, Cryptosporidium, Giardia and Cyclospora, and one nematode genus Ascaris, each of significant public health importance, is described. Standard electrorotation apparatus, consisting of micro-fabricated electrodes in a fluidic chip, quadrature sinusoidal signal generator, microscope and image capture system, was used to study each organism. Spectra of cellular rotation rate were recorded as a function of applied electric field frequency and compared with standardized biological tests, where appropriate, to illustrate the effectiveness and versatility of the electrorotation technique. Electrorotational determination of the viability of individual G. intestinalis cysts, Cryptosporidium parvum and Cyclospora cayetanensis oocysts has been achieved. The sporulation state of Cyclospora cayetanensis oocysts was also readily determined, as was the fertilization state of A. suum ova. Electrorotation is a simple, noninvasive and versatile analytical technique suited to a wide range of particle types and capable of incorporation into integrated Lab-on-a-chip devices.

New Optical Technique for the Generation of Quadrature Signals on Laser Doppler Velocimeter.

A novel laser Doppler velocimeter (LDV) technique which uses two single-frequency diode lasers, one for each LDV beam, is presented. The existing techniques using the optical frequency difference between two lasers for directional discrimination was enhanced by the technique discribed here. The Doppler frequency extracted by an optical superposition technique and a pair of quadrature signals in the base band was generated without any broadband electronic heterodyning. The electronic heterodyning on the conventional systems was implemented by an electronic mixing technique of the beat signal of the two lasers and the measuring signal generated by the scattered light of the LDV beams. This paper describes a new optical technique in contrast to these electronic heterodyning systems. In order to extract the Doppler frequency optically, undesired mixing products must be avoided. The realization of this concept is based on the superposition of four light waves on one photodetector, where only two pairs of light waves are made to forcedly interfere by polarization or by optical adjustment. Thus, the photodetector acts as an optoelectronic element that superimposes two optical beat signals, so that the Doppler frequency is obtained from the envelope of the resulting output signal directly. In order to obtain the desired directional information, a second photodetector for quadrature signal generation is required. The phase delay between the detected signals was fixed by positioning in the expanded wavefront of the reference beams. A prototype of the directional LDV, which uses two lasers and the described optical mixing, has been realized.

RC sequence asymmetric polyphase networks for RF integrated transceivers

Resistance-capacitance (RC) sequence asymmetric polyphase networks have recently gained a renewed interest in the design of radio-frequency integrated transceivers. These networks provide an efficient way for wideband quadrature signal generation with reduced sensitivity to component mismatch. In addition, polyphase networks represent a passive implementation of complex analog filters used for image signal suppression. The general behavior of this class of networks, as well as their distinct property of discriminating between positive and negative sequences, are discussed and evaluated analytically. A design methodology is proposed and a sensitivity analysis based on Monte Carlo simulation is presented. The effect of the absolute variation of R and C values on the phase and gain matching, as well as on the image signal suppression, is also investigated for one-, two-, and three-stage networks.

A novel spatial filtering velocimeter based on a photodetector array

In this paper, a new spatial filtering velocimeter is presented. A common charge-coupled device (CCD) has been used as spatial filter for one-component velocity measurements. Velocity estimation is based on an advantageous quadrature signal generation and appropriate signal processing.

New active RC-networks for the generation and detection of single-sideband signals

A class of polyphase active coupled networks for quadrature signal generation is presented. These networks employ resistors, lowprecision capacitors, and commercial integrated operational amplifiers. The sequence discrimination approach implemented in the analysis of these networks is very promising in single-sideband (SSB) generation and detection. It has the advantage of achieving both frequency translation and filtering in a single step. Consequently, the iteration problems associated with active filters at high frequencies are solved. It is shown that by applying feedback between the input and output terminals of these networks, both the gain and phase sensitivities to the component variations are improved. The performance of the proposed networks is analyzed and compared to that of the well-established all-pass realization. The superiority of the proposed networks, due to their relative insensitivity to the component variations, in comparison with the all-pass technique is also verified experimentally.