A mmWave Oscillator Design Utilizing High-Q Active-Mode On-Chip MEMS Resonators for Improved Fundamental Limits of Phase Noise (original) (raw)
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IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
This paper reports on the first demonstration of a 1.05-GHz microelectromechanical (MEMS) oscillator based on lateral-field-excited (LFE) piezoelectric AlN contourmode resonators. The oscillator shows a phase noise level of −81 dBc/Hz at 1-kHz offset frequency and a phase noise floor of −146 dBc/Hz, which satisfies the global system for mobile communications (GSM) requirements for ultra-high frequency (UHF) local oscillators (LO). The circuit was fabricated in the AMI semiconductor (AMIS) 0.5-μm complementary metaloxide-semiconductor (CMOS) process, with the oscillator core consuming only 3.5 mW DC power. The device overall performance has the best figure-of-merit (FoM) when compared with other gigahertz oscillators that are based on film bulk acoustic resonator (FBAR), surface acoustic wave (SAW), and CMOS on-chip inductor and capacitor (CMOS LC) technologies. A simple 2-mask process was used to fabricate the LFE AlN resonators operating between 843 MHz and 1.64 GHz with simultaneously high Q (up to 2,200) and k t 2 (up to 1.2%). This process further relaxes manufacturing tolerances and improves yield. All these advantages make these devices suitable for post-CMOS integrated on-chip direct gigahertz frequency synthesis in reconfigurable multiband wireless communications.
Design and Realization of a Fully On-Chip High-$Q$ Resonator at 15 GHz on Silicon
IEEE Transactions on Electron Devices, 2000
We develop and demonstrate an on-chip resonator working at 15 GHz with a high quality factor (Q-factor) of 93.81 while only requiring a small chip size of 195 μm × 195 μm on Si by using our new design methodology. In our design, unlike previous approaches, we avoid the need for any external capacitance for tuning; instead, we utilize the film capacitance as the capacitor of the LC tank circuit and realize a fully on-chip resonator that shows a strong transmission dip of > 30 dB on resonance as required for telemetric-sensing applications. We present the design, theory, methodology, microfabrication, experimental characterization, and theoretical analysis of these resonators. We also demonstrate that the experimental results are in excellent agreement with the theoretical (both analytical and numerical) results. Based on our proof-of-concept demonstration, such high-Q on-chip resonators hold great promise for use in transmissive telemetric sensors.
New planar high Q active resonator and its application to low phase noise oscillators
2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535)
This paper presents a new technique to design a high Q active resonator using an amplifier which is located at the loop of the resonator. By adjusting the phase of the loop, the equivalent negative resistance is generated at the one coupling port of the resonator, which leads to high Q property without the negative resistance circuit. The bandstop resonator using this technique shows a high Q factor of 548.62 from measurement at 10GHz resonant frequency. To demonstrate the validity of the proposed active resonator, an oscillator incorporated with this active resonator was designed, fabricated and measured. The phase noise performance of the active resonator oscillator is-112.6 dBc/Hz at 100KHz offset, which is reduced by 11.3-14.4dB compared to the passive resonator oscillator.
1.05 GHz MEMS oscillator based on lateral-field-excited piezoelectric AlN resonators
2009
This paper reports on the first demonstration of a 1.05 GHz microelectromechanical (MEMS) oscillator based on lateral-field-excited (LFE) piezoelectric Aluminum Nitride (AlN) contour-mode resonators. The oscillator shows a phase noise level of-81 dBc/Hz at 1 kHz offset frequency and a phase noise floor of-146 dBc/Hz, which satisfies the GSM requirements of Ultra High Frequency (UHF) local oscillators (LO). The circuit was fabricated in the AMIS 0.5 μm CMOS process, with the oscillator core consuming only 3.5 mW static power. A simple two-mask process was used to fabricate the LFE AlN resonators from 843 MHz to 1.64 GHz with high Q (up to 2,200) and k t 2 (up to 1.2%). This process further relaxes manufacturing tolerances and improves yield. All these advantages make it suitable for post-CMOS integrated on-chip direct GHz frequency synthesis in reconfigurable multi-band wireless communications. I.
Design of a MEMS-Based Oscillator Using 180nm CMOS Technology
PLOS ONE, 2016
Micro-electro mechanical system (MEMS) based oscillators are revolutionizing the timing industry as a cost effective solution, enhanced with more features, superior performance and better reliability. The design of a sustaining amplifier was triggered primarily to replenish MEMS resonator's high motion losses due to the possibility of their 'system-on-chip' integrated circuit solution. The design of a sustaining amplifier observing high gain and adequate phase shift for an electrostatic clamp-clamp (C-C) beam MEMS resonator, involves the use of an 180nm CMOS process with an unloaded Q of 1000 in realizing a fixed frequency oscillator. A net 122dBΩ transimpedance gain with adequate phase shift has ensured 17.22MHz resonant frequency oscillation with a layout area consumption of 0.121 mm 2 in the integrated chip solution, the sustaining amplifier draws 6.3mW with a respective phase noise of-84dBc/Hz at 1kHz offset is achieved within a noise floor of-103dB C /Hz. In this work, a comparison is drawn among similar design studies on the basis of a defined figure of merit (FOM). A low phase noise of 1kHz, high figure of merit and the smaller size of the chip has accredited to the design's applicability towards in the implementation of a clock generative integrated circuit. In addition to that, this complete silicon based MEMS oscillator in a monolithic solution has offered a cost effective solution for industrial or biomedical electronic applications.
Phase Feedback for Nonlinear MEM Resonators in Oscillator Circuits
IEEE-ASME Transactions on Mechatronics, 2009
In this paper, a phase feedback approach for using nonlinear microelectromechanical (MEM) resonators in oscillator circuits is investigated. Phase feedback makes use of the oscillation phase condition for oscillator circuits and enables fine-tuning of the frequency at which the resonator oscillates by means of setting the phase in the feedback amplifier. The principle of the approach is illustrated for a nonlinear Duffing resonator, which is representative of many types of MEM resonators. Next, the approach is applied to an electrostatically actuated nonlinear clamped-clamped beam MEM resonator, on simulation level. Phase feedback allows for operation of the resonator in its nonlinear regime. The closed-loop technique enables control of both the frequency of oscillation and the output power of the signal. Additionally, optimal operation points for oscillator circuits incorporating a nonlinear resonator can be defined. Application of phase feedback results in more robustness with respect to dynamic pull in than in open-loop case, however, at the cost of a deteriorated phase noise response.
Integrated CMOS-MEMS free-free beam resonators using pull-in mechanism to enable deep-submicrometer electrodeto-resonator gap spacing without interference in their mechanical boundary conditions (BCs) have been demonstrated simultaneously with low motional impedance and high Q. The key to attaining high Q relies on a decoupling design between pull-in frames for gap reduction and mechanical BCs of resonators. In addition, the use of metal-SiO 2 composite structures has been proved to greatly benefit the thermal stability of CMOS-MEMS resonators. Furthermore, tuning electrodes underneath pull-in frames were designed to offer "quasi-linear" frequency tuning capability where linear relationship between tuning voltage and frequency was achieved. In this paper, CMOS-MEMS free-free beam resonators with gap spacings of 110, 210, and 275 nm, respectively, were tested under direct one-port measurement in vacuum, demonstrating a resonator Q greater than 2000 and a motional impedance as low as 112 kΩ and, at the same time, allowing quasi-linear frequency tuning to achieve a total tuning range of 5000 ppm and a sensitivity of 83.3 ppm/V at 11.5 MHz with zero dc power consumption. Such a resonator monolithically integrated with a CMOS amplifier, totally occupying a die area of only 300 μm × 130 μm, was also tested with enhanced performance, benefiting future timing reference and RF synthesizing applications.
Sensors (Basel, Switzerland), 2018
The importance of micro-electromechanical systems (MEMS) for radio-frequency (RF) applications is rapidly growing. In RF mobile-communication systems, MEMS-based circuits enable a compact implementation, low power consumption and high RF performance, e.g., bulk-acoustic wave filters with low insertion loss and low noise or fast and reliable MEMS switches. However, the cross-hierarchical modelling of micro-electronic and micro-electromechanical constituents together in one multi-physical design process is still not as established as the design of integrated micro-electronic circuits, such as operational amplifiers. To close the gap between micro-electronics and micro-electromechanics, this paper presents an analytical approach towards the linear top-down design of MEMS resonators, based on their electrical specification, by the solution of the mechanical wave equation. In view of the central importance of thermal effects for the performance and stability of MEMS-based RF circuits, th...
IEEE Journal of Solid-State Circuits, 2018
This paper presents a millimeter-wave (mmW) frequency generation stage aimed at minimizing phase noise (PN) via waveform shaping and harmonic extraction while suppressing flicker noise upconversion via proper harmonic terminations. A 2nd-harmonic resonance is assisted by a proposed embedded decoupling capacitor inside a transformer for explicit commonmode current return path. Class-F operation with 3rd-harmonic boosting and extraction techniques allow maintaining high quality factor of a 10-GHz tank at the 30-GHz frequency generation. We further propose a comprehensive quantitative analysis method of flicker noise upconversion mechanism exploiting latest insights into the flicker noise mechanisms in nanoscale shortchannel transistors, and it is numerically verified against foundry models. The proposed 27.3-to 31.2-GHz oscillator is implemented in TSMC 28-nm CMOS. It achieves PN of −106 dBc/Hz at 1-MHz offset and figure-of-merit (FoM) of −184 dBc/Hz at 27.3 GHz. Its flicker phase-noise (1/ f 3) corner of 120 kHz is an order-ofmagnitude better than currently achievable at mmW.