Low Phase Noise Voltage-controlled Oscillator Research Articles

Design and analysis of a three-stage voltage-controlled ring oscillator

This paper describes a large tuning range low phase noise voltage-controlled ring oscillator (ring VCO) based on a different cascade voltage logic delay cell with current-source load to change the current of output node. The method for optimization is presented. Furthermore, the analysis of performance of the proposed ring VCO is confirmed by the measurement results. The three-stage proposed ring VCO was fabricated in the 180-nm CMOS process of SMIC. The measurement results show that the oscillator frequency of the ring VCO is from 0.770 to 5.286 GHz and the phase noise is 97.93 dBc/Hz at an offset of 1 MHz from 5.268 GHz with a total power of 15.1 mW from a 1.8 V supply while occupying only 0.00175 mm2 of the core die area.

A Switched Inductor Topology Using a Switchable Artificial Grounded Metal Guard Ring for Wide-FTR MMW VCO Applications

In conventional integrated circuit technologies, a grounded metal guard ring (MGR) is widely used to mitigate the coupling effect between any pair of inductors. Full-wave electromagnetic (EM) simulation results indicate that the guard ring size can significantly affect the inductance value of a single-turn planar inductor. This paper proposes a switchable artificial grounded MGR technique that can not only serve as a guard ring but also change the inductance. Accordingly, an inductor, featuring switchable inductance and high quality factor, is developed for a 60-GHz millimeter-wave wide-frequency tuning range (wide-FTR) and low phase-noise voltage-controlled oscillator (VCO) in 90-nm bulk CMOS technology. The VCO testkey achieves a total tuning range of 9.43 GHz (17%). The measured phase noise levels are -92.2 and -119 dBc/Hz at 1- and 10-MHz offsets, respectively. The experimental results demonstrate that the proposed inductor topology offers the VCO an increase of 36% in the FTR and a competitive performance in phase noise, as contrasted with a conventional varactor-tuned VCO. This VCO achieves a record of -188 dBc/Hz for the FOM <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> .

Design of High-Q Tunable SIW Resonator and Its Application to Low Phase Noise VCO

In this letter, a low-cost continuously tunable substrate integrated waveguide (SIW) resonator and a low phase noise SIW voltage-controlled oscillator (VCO) are presented. A simple new structure for coupling varactor to the SIW cavity is proposed, which realizes a simple circuit layout for the tuning resonator. Equivalent circuit model is given for the varactor coupled resonator. Relation between the coupling coefficient <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$k$</tex></formula> and the relative tuning bandwidth is analyzed. Prototypes of tunable SIW resonator and a low phase noise SIW VCO have been designed and fabricated. Measured results show that the proposed resonator possesses unloaded Q factor of 286–299 for a tuning range of 492 MHz, and the phase noise of the SIW VCO is <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${- 93}\mathchar"707B -95.6~{\rm dBc}/{\rm Hz}$</tex></formula> at 100 kHz offset for the whole oscillating frequency range of 455 MHz at X-Band.

SIW-Based Low Phase-Noise Millimeter-Wave Planar Dual-Port Voltage-Controlled Oscillator

In this paper, a low phase-noise millimeter-wave planar dual-port voltage-controlled oscillator (VCO) using a novel electronically tunable substrate integrated waveguide (SIW) resonator is proposed. The VCO operates in the Ka- and E-band simultaneously. At the fundamental-wave port, the VCO achieves a tuning rang of more than 120MHz by varying the varactor tuning voltage from 0 to 11V, spurious output less than −40 dBc, and a phase-noise of −114.7 dBc/Hz at 1MHz offset from 32 GHz carrier frequency. Meanwhile, at the harmonic port, a tuning rang of more than 240MHz around 64GHz carrier frequency is achieved. The measured output power varies from 6.04 to 8.75 dBm and 7.2 to 9.46 dBm within the fundamental-wave and second harmonic tuning ranges, respectively. This type of low phase-noise planar dual-port VCO is very suitable for millimeter-wave applications in high stable phase-locked sources or FMCW radars.

High-Q metamaterial interdigital transmission line based on complementary spiral resonators for low phase noise voltage-controlled oscillator

In this study, the high-quality factor ( Q ) metamaterial interdigital transmission line (TL) based on the complementary spiral resonators (CSRs) is presented for reducing the phase noise of the voltage-controlled oscillator (VCO). The high- Q metamaterial TL is realised by adopting the array of the CSRs etched on the ground plane and the interdigital centre line on the signal plane. The interdigital centre line on the signal plane has been used to obtain higher Q value than that of the conventional implementation. The resonance properties and inherent Q value saturation of the proposed high- Q metamaterial interdigital TL have been analysed as follows: width of the centre line on the signal plane, dimensions of the CSRs, current directions between the CSRs, number of the unit cell-pair of the CSRs and whether or not there is the interdigital structure. The phase noise and tuning range of the proposed VCO are -127.50 to -124.87-dBc/Hz at 100-kHz and 5.744-5.86-GHz.

Low Phase Noise and Wide Tuning Range VCO Using the MOS Differential Amplifier with Active Load

We demonstrate the design of a novel voltage-controlled oscillator (VCO), which is based on a metal-oxide-semiconductor field-effect transistor (MOS) differential amplifier with active load. This VCO achieves low phase noise and wide tuning range. The phase noise is –120 dBc/Hz at 600 KHz offset from a 1.216 GHz carrier frequency. This value is comparable to that of a LC-based integrated oscillator. The operating frequency can be tuned from 117 MHz to 1.216 GHz with the supply voltage varying from 1.3 V to 3.3 V. Therefore, the tuning range is about 90.38% which is larger than most of the LC and ring oscillator. The VCO circuit, which is constructed using a standard 0.35 μm CMOS technology, occupies only 26.25 × 7.52 μm2 die area and dissipated 10.56 mW under a 3.3 V supply voltage.

Microstrip Square Open Loop Metamaterial Resonator and Rat Race Coupler for Low Phase Noise Push-Push VCO

In this paper, a novel low phase noise voltage-controlled oscillator (VCO) using metamaterial structure and rat race coupler is presented for reducing the phase noise without the reduction of the frequency tuning range. The metamaterial structure has been realized by microstrip square open loop double split ring resonator (SRR). The rat race coupler shows slightly higher transmission compared to a Wilkinson combiner and is, therefore, used instead to improve the performances of VCO. By providing these unique modifications, the proposed push-push VCO has a phase noise of -126.30~-124.83 dBc/Hz at 100 kHz in the tuning range of 5.672~5.800 GHz.

Low phase-noise VCO utilizing modified symmetric load and partial positive feedback for FDSM

The voltage-controlled oscillator (VCO) in frequency-based $$\Updelta\Upsigma$$ modulator (FDSM) systems behaves as a voltage-to-phase integrator converting an analog input voltage to phase informa...

Low Phase Noise and Low Power Consumption VCOs Using CMOS and IPD Technologies

This paper presents two voltage controlled oscillators (VCOs) operating at 5.42 and 5.76 GHz implemented in 0.18-μm complementary metal-oxide semiconductor (CMOS) technology with integrated passive device (IPD) inductors. One IPD inductor was stacked on the top of the active region of the 5.76-GHz VCO chip, whereas the other IPD inductor was placed on the top of the 5.42-GHz VCO CMOS chip but far from the its active region. The high-quality IPD inductors reduce the phase noise of the VCOs. The measurements of the two VCOs indicate the same phase noise of -120 dBc/Hz at 1 MHz offset frequency. These results demonstrate a 6-dB improvement compared to the VCO using an on-chip inductor. This paper also presents the effect of the coupling between the IPD inductor and the active region of the chip on the phase noise performance.

Design and Simulation of Low Phase Noise Voltage-Controlled Oscillator

This paper presents the design and simulation of a low phase noise voltage-controlled oscillator (VCO). The oscillator is based upon the classic LC-tuned negative-resistance topology, with a passive inductor. A fundamental relationship of the channel length of MOS transistors in LC tanks VCO and the phase noise is presented. The proposed VCO in the 0.18µm process is designed which is suitable for system integration in transceiver designs. Using this process, complete pattern VCO is designed in ADS. It operates in the 5.5 GHz frequency range with a 1.8V power supply. The power consumption is 7.592mW. The VCO's phase noise level is -106.4dBc/Hz at 1MHz offset.

A Low Phase-Noise VCO Using an Electronically Tunable Substrate Integrated Waveguide Resonator

In this paper, an X -band low phase-noise voltage-controlled oscillator (VCO) using a novel electronically tunable substrate integrated waveguide (SIW) resonator is proposed and developed for RF/microwave applications on the basis of the substrate integrated circuits concept. In this case, the resonant frequency of the SIW cavity resonator is tuned by different dc-biasing voltages applied over a varactor coupled to the cavity. Measured results show that the tuning range of the resonator is about 630 MHz with an unloaded Q U of 138. Subsequently, a novel reflection-type low phase noise VCO is developed by taking advantage of the proposed tunable resonator. Measured results demonstrate a frequency tuning range of 460 MHz and a phase noise of 88 dBc/Hz at a 100-kHz offset over all oscillation frequencies. The VCO is also able to deliver an output power from 6.5 to 10 dBm. This type of VCO is very suitable for low-cost microwave and millimeter-wave applications.

A Low Phase Noise Voltage-Controlled Oscillator with Harmonic Suppression Based on LTCC Technology

In this paper, a low phase noise hybrid integrated voltage-controlled oscillator (VCO) module with harmonic suppression based on LTCC technology is presented. This is the first report about the hybrid integrated VCO module based on the LTCC substrate in china mainland. The design is simulated and optimized by the ansoft designer and the ansoft HFSS software. To miniaturize the VCO module, two capacitors and an inductor that adjust the oscillation frequency and two capacitors as feedback capacitors are buried in the LTCC substrate. Three resistances for direct current bias are made on the surface of the LTCC substrate. Also the low-pass filter that used for harmonic suppression is embedded in the LTCC substrate. The VCO module achieves an output power of more than 10 dBm in a tuning range between 1000-1200MHz. The measured phase noise is lower than -112.2 dBc/Hz at 10KHz offset between 1000-1200MHz. The overall dimension is as small as 8 mm×7 mm×3.5 mm.

A Second Harmonic Suppression CMOS Crosscoupled VCO Using Active Inductor Technique for WLAN System Applications

In this paper, a low phase-noise CMOS cross-coupled voltage-controlled oscillator (VCO) using an active inductor for wireless local area network (WLAN) applications is presented. The proposed VCO achieves low phase-noise by using the active inductor to suppress the second harmonic (2 ω0 ) of LC tank. The VCO achieves –125.8 dBc/Hz phase-noise at 1 MHz offset from the 2.33 GHz carrier frequency, and frequency tuning range is about 25% from 2.01 to 2.62 GHz. This VCO consumes 2.3 mA from a 1.8 V supply with chip area of 0.75 × 0.64 mm2.

A 6 GHz high power and low phase noise VCO using an InGaP/GaAs HBT

A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of −122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was −179.2 dBc/Hz.

A Low Phase Noise $LC$ VCO in 65 nm CMOS Process Using Rectangular Switching Technique

A low phase noise and low power LC voltage-controlled oscillator (VCO) has been designed using a 65-nm CMOS process. The phase noise is minimized by switching the differential core using a rectangular shaped voltage waveform, which is formed by a harmonic tuned LC tank assisted by a gm3 boosting circuit. The gm3 boosting circuit effectively maximizes the slope at the zero crossing point and reduces the transition time in which the switching transistor is operated at the triode region. The rectangular switching technique has improved the phase noise of the oscillator by 10 dB. The 450 mum times 540 mum chip consumes 4.34 mW. The proposed VCO has phase noises of -83.3, -110.7, and -131.8 dBc/Hz at 10 KHz, 100 KHz, and 1 MHz offset frequencies, respectively, from the 1.6-GHz carrier frequency.

A low phase-noise CMOS VCO with harmonic tuned LC tank

This paper presents a phase-noise reduction technique for voltage-controlled oscillators (VCOs) using a harmonic tuned (HT) LC tank. The phase-noise suppression is achieved through almost rectangular-shaped voltage at the switching differential cell, which effectively maximizes the slope of the switching cell output voltage at a zero crossing point. In addition, the proposed technique also suppresses the down-conversion of the noise around the second harmonic frequency by the second harmonic short of the tank. One second HT VCO and two third HT VCOs are designed and implemented to evaluate the concept using a 0.35- and 0.13-/spl mu/m CMOS process. The figure-of-merit (FOM) of the second HT VCO, third HT VCO1, and third HT VCO2 are -180.7, -183.7, and -189.5, respectively. The best FOM performance of the VCO has phase noises of -100.4, -132.0, and -140.8dBc/Hz at 100-kHz, 1-MHz, and 3-MHz offset frequencies at the 2-GHz carrier, respectively. This VCO consumes 3.29 mA from a 1.8-V supply with the silicon area of 500 /spl mu/m/spl times/750 /spl mu/m.

Variable inductance planar spiral inductors and CMOS wideband amplifiers with inductive peaking

In this paper, a complete set of variable inductance (VI) planar spiral inductors with MOSFET switches are characterized and modeled for the first time. These VI inductors can be used to optimize the performances of CMOS wideband low-noise amplifiers (LNAs) with inductive peaking, to implement low-phase noise voltage-controlled oscillators (VCOs), and so on. Moreover, the experimental results show that series-inductive peaking can effectively improve the bandwidth of the CMOS wideband LNAs. For a CMOS wideband LNA with a 0.58-nH peaking inductor, a 74.2% (from 3.1 to 5.4 GHz) increase in bandwidth is achieved. The measured noise figures (NFs) are 2.2 dB at 1 GHz and 4.0 dB at 6 GHz. The measured input 3rd-order intercepting point (IIP3) is −3 dBm at 3 GHz. These results show that the performances of CMOS wideband LNAs can be improved by inductive peaking, which can be optimized by our developed VI inductors. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 305–309, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21153

A compact and low-phase-noise Ka-band pHEMT-based VCO

A low phase-noise Ka-band monolithic voltage-controlled oscillator (VCO) designed using the negative resistance concept is reported. A circuit fabricated using the three-dimensional monolithic microwave integrated circuit technology exhibits a high integration level; its size is a record at just 0.5 mm/sup 2/. On-wafer measurements demonstrate a low phase noise of -102 dBc/Hz at a 1-MHz offset. The VCO delivers an output power of 11.8 dBm at the center frequency of 28.3 GHz. The frequency tuning range is more than 3.8 GHz. Dependence of the circuit performance on the bias conditions is also reported and suggests that an optimum phase-noise characteristic can be achieved when biasing the transistor to optimize its transconductance and noise figure.

Fully integrated low phase-noise VCOs with on-chip MEMS inductors

We present fully integrated high-performance voltage-controlled oscillators (VCOs) with on-chip microelectromechanical system (MEMS) inductors for the first time. MEMS inductors have been realized from the unique CMOS-compatible MEMS process that we have developed to provide suspended thick metal structures for high-quality (Q) factors. Fully integrated CMOS VCOs have been fabricated by monolithically integrating these MEMS inductors on the top of the CMOS active circuits realized by the TSMC 0.18-/spl mu/m mixed-mode CMOS process. Low phase noise has been achieved as -124 and -117 dBc/Hz at 300-kHz offset from carrier frequencies of 1 and 2.6 GHz, respectively, in the fabricated single-chip VCOs.

Correction to ?A micromachined RF low phase noise voltage-controlled oscillator for wireless communications?

Correction to ?A micromachined RF low phase noise voltage-controlled oscillator for wireless communications?