A low phase noise super–harmonic coupling quadrature VCO using an additional double frequency oscillator

Jafari, Bahram; Sheikhaei, Samad

doi:10.1016/j.mejo.2018.08.007

Cited by 9 publications

(7 citation statements)

References 24 publications

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“…Therefore, the coupling network only includes two noiseless and lossless passive elements and does not add any extra noise sources and DC power consumption to the cores. It is worth noting that the proposed coupling network needs a lower chip area than the traditional transformer couplings (Ravi et al, 2002;Gierkink et al, 2003) and master-slave paradigms (Ravi et al, 2002;Jafari and Sheikhaei, 2018a).…”

Section: Proposed Switching Superharmonic Coupling Schemementioning

confidence: 99%

“…To generate quadrature signals, different techniques exist (Razavi, 2011) as such: using ring oscillator; while it has a wide tuning range, it is not popular for modern radio frequency systems because of its poor phase noise performance; the use of Resistor-Capacitor and Capacitor-Resistor circuit and transformer-based poly-phase filters (Park and Wang, 2015), which has a poor phase accuracy because of high mismatch of the resistor-capacitor circuit-based time constant in the CMOS process, and also, it needs power hungry buffers; the use of an oscillator followed by a master-slave flip-flop as a frequency divider which is less attractive because of power and frequency limitations and sensitivity of quadrature accuracy to duty cycle; and the use of injection-locked inductor-capacitor circuit (LC)-QVCOs, which because of good phase noise performance of LC-voltage-controlled oscillators (VCOs) has become widely popular in a RF-integrated circuit design (Rofougaran, 1998;Andreani et al 2002;Ebrahimi and Naseh, 2013;Ebrahimi and Naseh, 2011;Ravi et al, 2002;Gierkink et al, 2003;Hancock and Rebeiz, 2004;Naseh et al, 2008;Soltanian and Kinget, 2006;Yu et al, 2016;Kuo et al, 2015;Jafari and Sheikhaei, 2018a).…”

Section: Introductionmentioning

confidence: 99%

“…However, this configuration has some shortcomings such as poor phase noise, high power consumption and needs for large chip area because of additional VCO (Master). Recently in a study conducted by Jafari and Sheikhaei (2018a), this concept is modified as shown in Figure 1(c) to reduce flicker noise and close-in phase noise by switching mechanism of tail transistors. While this technique is effective, some issues such as high power consumption and chip area remain.…”

Section: Introductionmentioning

confidence: 99%

“…In other words, the presented circuits in the studies conducted by Naseh et al (2008), Soltanian and Kinget (2006) and Hemmati and Naseh (2011) are in quadrature only for a narrow region of the circuit parameters, and there are no clear design guides to find this region. It is worth mentioning, the proposed QVCOs in the studies conducted by Ebrahimi and Naseh (2011); Gierkink et al (2003); Hancock and Rebeiz (2004); Kuo et al (2015) and Jafari and Sheikhaei (2018a) have a good robustness because of enforcing 180°phase shift by coupling elements or mechanism.…”

Section: Introductionmentioning

confidence: 99%

“…The flicker noise directly affects close-in phase noise (1/f 3 region), while the thermal noise is dominated at 1/f 2 region (Gierkink et al, 2003). According to Huang and Kim (2009), cycling transistors from strong inversion to accumulation reduces flicker noise and, therefore, improves close-in phase noise of VCOs (Jafari and Sheikhaei, 2018a;Natarajan et al, 2018;Jiang and Luong, 2017;Jafari and Sheikhaei, 2018b).…”

Section: Introductionmentioning

confidence: 99%

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A new tail-switching superharmonic multiphase LC-VCO

Ebrahimi

2020

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Purpose Multiphase and quadrature voltage-controlled oscillators (QVCOs) play key roles in modern communication systems and their phase noise performance affects the performance of the overall system. Different studies are devoted to efficient quadrature signals generation. This paper aims to present a new low-phase noise superharmonic injection-locked QVCO. Design/methodology/approach The proposed QVCO is comprised of two identical inductor-capacitor circuit (LC)-voltage-controlled oscillators (VCOs) in which second harmonics, with 180° phase shift, are injected from one core VCO to the gate of tail current source of the other VCO via a coupling capacitor. Using second harmonics with high amplitude will switch the tail from the inversion to the accumulation, and therefore, flicker noise is reduced. Also, because of the use of lossless and noiseless coupling elements, that is, coupling capacitors, and also because of the existence of an inherent high-pass filter, the proposed LC-QVCO has a good phase noise performance. Findings The introduced technique is designed and simulated in a commercial 0.18 µm radio frequency complementary metal oxide semiconductor (RF-CMOS) technology and 10 dB improvement of close-in phase noise is achieved (compared to the conventional method). Simulation results show that the phase noise of the proposed QVCO is −130.3 dBc/Hz at 3 MHz offset from 5.76 GHz center frequency, while the total direct current (DC) current drawn from a 0.9-V power supply is 4.25 mA (figure of merit = −190.2 dBc). Monte Carlo simulation results show that the figure of merit of the circuit has a Gaussian distribution with mean value and standard deviation of −189.97 dBc and 0.183, respectively. Originality/value This technique provides a new simple but efficient superharmonic coupling and noise shaping method that reduces close-in phase noise of superharmonic multiphase VCOs by switching of tail transistors with 2 ω0 (second harmonic of oscillation frequency). No extra devices such as area-consuming transformer or additional power-hungry oscillator are used for coupling.

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Section: Proposed Switching Superharmonic Coupling Schemementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A new tail-switching superharmonic multiphase LC-VCO

Ebrahimi

2020

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A low phase noise quadrature VCO using super‐harmonic coupling technique in 65‐nm CMOS technology

Ghasemi,

Karami

2023

Circuit Theory & Apps

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SummaryThis paper presents a new low phase noise (PN) quadrature voltage controller oscillator (QVCO), which includes four class C LC‐VCOs oscillated at 13 GHz operating frequency with 45‐degree phase differences from each other. By combining the second harmonics (super‐harmonic) of the LC‐VCOs, the quadrature outputs with low PN at 26 GHz are generated. To assess the performance of the proposed QVCO, post‐layout simulations are performed in 65‐nm CMOS technology with a 0.6 V supply voltage. The post‐layout results represent that the proposed circuit has 26 GHz quadrature outputs with the PN of −116.4 at 1 MHz offset frequency. Also, the proposed QVCO occupies an area of 0.366 mm2 and consumes 10.4 mW of power. Therefore, the proposed QVCO is a good candidate for 5G applications.

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Two implementations of 120 GHz transformer cross‐coupled oscillator based on cascode structure in 55 nm CMOS technology

Yang

2022

Micro & Optical Tech Letters

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Two oscillators are designed and fabricated, focusing on the output power and tuning range in the terahertz band. The first one is a transformer crosscoupled oscillator based on the cascode structure, and the second one is a self-mixing transformer cross-coupled oscillator. Higher output power is obtained by using transformer coupling instead of direct or capacitive coupling. Using the frequency mixing principle, a wider tuning range is obtained. Both chips are processed by 55 nm CMOS technology. The measured frequency tuning range is 115.9-129.1 and 110.8-128.0 GHz, respectively. The measured peak value of output power is 3.2 and −14.3 dBm, respectively.

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A low phase noise super–harmonic coupling quadrature VCO using an additional double frequency oscillator

Cited by 9 publications

References 24 publications

A new tail-switching superharmonic multiphase LC-VCO

A new tail-switching superharmonic multiphase LC-VCO

A low phase noise quadrature VCO using super‐harmonic coupling technique in 65‐nm CMOS technology

Two implementations of 120 GHz transformer cross‐coupled oscillator based on cascode structure in 55 nm CMOS technology

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