A 2.5 V, 10 GHz Fully Integrated LC-VCO with Integrated High-Q Inductor and 30% Tuning Range

A 10 GHz fully integrated Voltage Controlled Oscillator is presented. A 29.7% tuning range is achieved from a 2.5 V power supply. The phase noise is –113 dBc/Hz at 600 kHz and –127 dBc/Hz at 3 MHz. The VCO is implemented in a 0.25 m 4 metal layer standard CMOS technology. This design will be used to discuss design and layout issues for high frequency LC-oscillators. A thorough analysis will be made of the contribution of the different building blocks to the performance of the total circuit.     

L波段宽带低相噪VCO的设计与制作

提出了一种基于PCB工艺的L波段宽带低相噪VCO电路拓扑结构.采用基极和发射极双端调谐的方式,并引入可变电容反馈,实现了电路的超宽带.同时在低损耗的FR4基板上制作微带小电感以形成高Q谐振器,降低了VCO的相位噪声.基于此方法设计得到的L波段宽带VCO比同类薄膜工艺产品相位噪声低了5 dB以上.     

Differentially-Tuned VCO with Reduced Tuning Sensitivity and Flicker Noise Up-Conversion

Differential tuning in oscillators allows cancellation of common-mode bias noise and lower tuning sensitivity with respect to the most conventional single-ended tuning. However, the direct application of differential tuning increases the capacitor non-linearity and the flicker-induced phase noise. This paper analyzes quantitatively this phenomenon and proposes a novel configuration, which includes all the benefits of differential tuning with no penalty on phase noise. This circuit is fabricated in a 0.35-m CMOS technology together with a single-end-tuned oscillator and both cover the 2.0–2.4 GHz frequency range. The measured 1/f³ phase noise at 10 kHz offset is –71 dBc/Hz, which outperforms the companion single-end tuning oscillator by 10 dB.A.L. Lacaita is also with IFN-CNR Sezione Milano.Salvatore Levantino was born in 1973. He received the degree of Ingegnere in 1998 and the Ph.D. degree in electrical engineering in 2001 from the Politecnico di Milano, Italy. During his PhD program, he studied noise generation mechanisms in integrated oscillators and novel topologies for agile frequency synthesis. He also spent one year at Agere Systems (formerly Bell Laboratories), Murray Hill, NJ, working as consultant on IF-sampling receiver architectures. Since 2002, he is a post-doctoral researcher at the Politecnico di Milano. His research interests are mainly focused on fully integrated transceivers for wireless applications.Andrea Bonfanti was born in Besana B.za (Milan), Italy, in 1972. He received the Laurea Degree and the Ph.D. in electronics engineering from the Politecnico di Milano, Italy, in 1999 and in 2002, respectively. Since 2003, he is a post-doctoral researcher at the Politecnico di Milano. His activity is focused on the design of frequency synthesizers for wireless applications in CMOS. His research interests also include analog-to-digital converters.Luca Romanó was born in Milan, Italy, in 1976. He received the Laurea Degree in electronics engineering from the Politecnico di Milano, Milan, Italy, in 2001. He is currently working toward the Ph.D. degree in electronics and communications at the Politecnico di Milano. His research activity is oriented towards the development of frequency synthesizers for wireless broadband communications.Carlo Samori was born in 1966, in Perugia, Italy. He received the Laurea Degree in electronics engineering in 1992, and the Ph.D. in electronics and communications at the Politecnico di Milano, Italy, in 1995. In 2002, he was appointed Associate Professor of Electronics at the Politecnico di Milano. He worked on solid-state photo-detector and the associated front-end electronics. His current research interests include design and analysis of integrated circuits for communications in bipolar and CMOS technologies, noise analysis in oscillators, frequency synthesizer architectures. Since 1997, he is a Consultant of the Wireless Communication Circuit Research Department of Agere Systems, Murray Hill.Andrea L. Lacaita was born in 1962. He received the Laurea degree in nuclear engineering from the Politecnico di Milano, Italy, in 1985. In 1989–90, he was Visiting Scientist at the AT&T Bell Laboratories, Murray Hill, NJ, working on photo-refractive effects in superlattices for optical switching. In 1992, he became Associate Professor of Electronics at the Politecnico of Milano and since then, he has been teaching courses on electronics, electron devices, optoelectronics and solid-state physics. In 1999, he has been Academic Visitor at IBM T.J. Watson Research Center, Yorktown Heights, NY, where he contributed to the development of optical systems for IC testing. In 2000, he was appointed Full Professor of Electronics at the Politecnico di Milano and Head of the Microelectronics Lab. As researcher, he contributed to analog IC design with studies of phase noise in integrated LC-tuned oscillators and with the development of novel architectures of frequency synthesizers in RF front-ends. He has contributed to advances in microelectronics and optoelectronics, with particular emphasis on physics of single photon avalanche detectors, characterization and modeling of semiconductor devices. Within the field of ULSI microelectronics, he has studied carrier transport and quantum effect in scaled MOS transistors, technology and reliability of non-volatile memories. He is co-author of about 150 papers published in journals or presented in international conferences. He is also author of two books in Electronics.Prof. Lacaita received in 1993 the Award of the Italian Association of Electrical and Electronic Engineers (AEI) for his research on hot carrier effects. In 1998–2000, he served as Coordinator of the Committee on micro-and nano-electron devices of the Italian National Group of Electronics Engineers. Since 2000, he has been consultant for the European Commission in the evaluation on review of research projects in micro- and nano-electronics. Since 2001, he has been serving in the program committee of the IEEE International Electron Device Meeting (IEDM) and he is now European Chair.     

宽带LC压控振荡器的相位噪声优化设计

采用0.35 μm BiCMOS工艺,设计了一款基于开关电容阵列结构的宽带LC压控振荡器.同时分析了电路中关键参数对相位噪声的影响.基于对VCO中LC谐振回路品质因数的分析,优化了谐振回路,提高了谐振回路的品质因数以降低VCO的相位噪声.采用噪声滤波技术,减小了电流源晶体管噪声对压控振荡器相位噪声的影响.测试结果表明,优化后的压控振荡器能够覆盖1.96～2.70 GHz的带宽,频偏为100 kHz和1 MHz的相位噪声分别为-105和-128 dBc/Hz,满足了集成锁相环对压控振荡器的指标要求.     

宽带低相噪CMOS LC VCO的设计

设计了一款宽带CMOSLCVCO,在分析VCO相位噪声来源的基础上,对VCO进行了结构优化和噪声滤除,并采用了开关电容阵列以增加带宽。电路采用0.18μmCMOS射频工艺进行流片验证,芯片面积为0.4mm×1mm。测试结果显示:芯片的工作频率为3.34～4.17GHz,中心频率为4.02GHz时输出功率是-9.11dBm,相位噪声为-120dBc/Hz@1MHz,在1.8V工作电压下的功耗为10mW。     

Ka波段低相位噪声GaAs MHEMT单片压控振荡器

报道了一种低相位噪声VCOMMIC芯片,采用传统的源端反馈形成负阻来消除谐振回路中的寄生电阻,通过合理的输出匹配实现起振条件并抑制谐波,利用南京电子器件研究所0.15μmGaAsMHEMT工艺,研制的Ka波段GaAsMHEMT压控振荡器,典型振荡频率为39.34GHz,频率变化范围38.6～41.3GHz之间,调谐带宽2.7GHz,典型输出功率6.97dBm,频偏100kHz,相位噪声为-81.1dBc/Hz。     

一种带有升压电路的0.5 V 3 GHz低功耗LC VCO设计

采用标准的0.13μm CMOS工艺实现了0.5V电源电压,3GHz LC压控振荡器。为了适应低电压工作,并实现低相位噪声,该压控振荡器采用了NMOS差分对的电压偏置振荡器结构,去除尾电流,以尾电感代替,采用感性压控端,增加升压电路结构使变容管的一端升压,这样控制电压变化范围得到扩展。测试结果显示,当电源电压为0.5V,振荡频率为3.126GHz时,在相位噪声为-113.83dBc/Hz@1MHz,调谐范围为12%,核心电路功耗仅1.765mW,该振荡器的归一化品质因数可达-186.2dB,芯片面积为0.96mm×0.9mm。     

1.8 GHz相位噪声优化的差分压控振荡器

针对DCS-1800标准，设计了应用于频率综合器中的差分压控振荡器。采用噪声滤波器，降低了VCO的相位噪声；采用片上电感，压控振荡器可以单片集成。其可调频率为1660～1815MHz，在偏置频率为600kHz的条件下，仿真测得的相位噪声为-125dBc／Hz。整个VCO的工作电压为2．5V，工作电流为6mA。     

Improvement of Noise Performance in Phased‐Array Receivers

This paper presents a new analytical approach and experimental verification for the improvement of noise performance in phased‐array receivers. For analysis purposes, a multi‐channel array system is converted into an equivalent single‐channel system, such that the two presents the identical signal and noise powers at the output, respectively. We define an effective gain, noise figure, and signal‐to‐noise ratio in the equivalent system. Through the proposed approach, the noise performance of the array receiver is analyzed in a general and straightforward manner and then compared to that of each individual array channel. In addition, the phase noise of the array system is analyzed in a rigorous manner, showing its effective reduction by a factor of the array size. The predicted improvement of the noise performance is experimentally confirmed with a CMOS integrated phased‐array receiver.     

A Co‐design Study of Filters and Oscillator for Low Phase Noise and High Harmonic Rejection

In this paper, we present a novel oscillator (OSC) design. Bandpass filters, which can suppress harmonics, are incorporated into a co‐design with an OSC to improve the OSC phase noise and harmonic rejection. The proposed OSC/bandpass filter co‐design achieves a phase noise of ?130.1 dBc/Hz/600 kHz and harmonic rejection of 37.94 dB and 40.85 dB for the second and third harmonics, respectively, as compared to results achieved by the OSC before co‐design of ?101.6 dBc/Hz/600 kHz and 21.28 dB and 19.68 dB. Good agreement between the measured and simulated results is achieved.     

A Linear Prediction Based Estimation of Signal‐to‐Noise Ratio in AWGN Channel

Most signal‐to‐noise ratio (SNR) estimation techniques in digital communication channels derive the SNR estimates solely from samples of the received signal after the matched filter. They are based on symbol SNR and assume perfect synchronization and intersymbol interference (ISI)‐free symbols. In severe channel distortion where ISI is significant, the performance of these estimators badly deteriorates. We propose an SNR estimator which can operate on data samples collected at the front‐end of a receiver or at the input to the decision device. This will relax the restrictions over channel distortions and help extend the application of SNR estimators beyond system monitoring. The proposed estimator uses the characteristics of the second order moments of the additive white Gaussian noise digital communication channel and a linear predictor based on the modified‐covariance algorithm in estimating the SNR value. The performance of the proposed technique is investigated and compared with other in‐service SNR estimators in digital communication channels. The simulated performance is also compared to the Cramér‐Rao bound as derived at the input of the decision circuit.     

Novel Phase Noise Reduction Method for CPW‐Based Microwave Oscillator Circuit Utilizing a Compact Planar Helical Resonator

This letter describes a compact printed helical resonator and its application to a microwave oscillator circuit implemented in coplanar waveguide (CPW) technology. The high quality (Q)‐factor and spurious‐free characteristic of the resonator contribute to the phase noise reduction and the harmonic suppression of the resulting oscillator circuit, respectively. The designed resonator showed a loaded Q‐factor of 180 in a chip area of only 40% of the corresponding miniaturized hairpin resonator without any spurious resonances. The fully planar oscillator incorporated with this resonator showed an additional phase noise reduction of 10.5 dB at a 1 MHz offset and a second harmonic suppression enhancement of 6 dB when compared to those of a conventional CPW oscillator without the planar helical resonator structure.     

Application of VSI‐EBG Structure to High‐Speed Differential Signals for Wideband Suppression of Common‐Mode Noise

In this paper, we present wideband common‐mode (CM) noise suppression using a vertical stepped impedance electromagnetic bandgap (VSI‐EBG) structure for high‐speed differential signals in multilayer printed circuit boards. This technique is an original design that enables us to apply the VSI‐EBG structure to differential signals without sacrificing the differential characteristics. In addition, the analytical dispersion equations for the bandgap prediction of the CM propagation in the VSI‐EBG structure are extracted, and the closed‐form expressions for the bandgap cutoff frequencies are derived. Based on the dispersion equations, the effects of the impedance ratio, the EBG patch length, and via inductances on the bandgap of the VSI‐EBG structure for differential signals are thoroughly examined. The proposed dispersion equations are verified through agreement with the full‐wave simulation results. It is experimentally demonstrated that the proposed VSI‐EBG structure for differential signaling suppresses the CM noise in the wideband frequency range without degrading the differential characteristics.     

High‐Speed Traveling‐Wave Photodetector with a 3‐dB Bandwidth of 410 GHz

A high‐speed traveling‐wave photodetector (TWPD) with an InGaAs absorber is designed and realized. The bandwidth of the TWPD is measured using electro‐optic sampling techniques. The bandwidth is 410 GHz, which shows that the RC limitation is overcome. While the TWPD shows a low responsivity of 0.06 A/W at 1,550 nm, this value can be improved through further optimization of the structure without a sacrifice in bandwidth.     

一种高增益低噪声5．25GHz Gilbert混频器的设计

基于Gilbert单元,本文采用0．18μm CM OS工艺设计了一个工作在5．25G Hz的高增益、低噪声下变频双平衡混频器．该混频器采用电流注入技术以减少流经开关管和负载的电流,缓解电压裕度和功耗的限制．采用谐振电感抑制寄生电容的充放电,减小流入寄生电容的电流,从而降低闪烁噪声．在跨导管的源极接入电感,形成负反馈电路,从而提高了电路的线性度．基于0．18 mm CM OS工艺与1．8V电源电压的后仿真表明,下变频混频器具有良好的250M Hz中频输出特性,电路匹配良好,测试得到的转换增益为22．65dB ,输入三阶交调点为-7．66dBm ,在中频250M Hz处的单边带噪声系数为5．58dB ,整个电路的功耗为8．64mW ．     

Low Voltage CMOS LC VCO with Switched Self‐Biasing

This paper presents a switched self‐biasing and a tail current‐shaping technique to suppress the 1/f noise from a tail current source in differential cross‐coupled inductance‐capacitance (LC) voltage‐controlled oscillators (VCOs). The proposed LC VCO has an amplitude control characteristic due to the creation of negative feedback for the oscillation waveform amplitude. It is fabricated using a 0.13 µm CMOS process. The measured phase noise is ‐117 dBc/Hz at a 1 MHz offset from a 4.85 GHz carrier frequency, while it draws 6.5 mA from a 0.6 V supply voltage. For frequency tuning, process variation, and temperature change, the amplitude change rate of the oscillation waveform in the proposed VCO is 2.1 to 3.2 times smaller than that of an existing VCO with a fixed bias. The measured amplitude change rate of the oscillation waveform for frequency tuning from 4.55 GHz to 5.04 GHz is 131 pV/Hz.     

一种低噪声快速转换频率合成器的设计与实现

介绍了一种低相位噪声、快速转换频率合成器的设计与实现,采用DDS、变带宽、频率预置等多种措施,频率转换时间〈80μs,并对实验结果进行了分析讨论。实验结果表明,该合成器相位噪声具有良好、锁定时间短,适合在超短波电台中应用。     

Simple Detection Based on Soft‐Limiting for Binary Transmission in a Mixture of Generalized Normal‐Laplace Distributed Noise and Gaussian Noise

In this letter, a simplified suboptimum receiver based on soft‐limiting for the detection of binary antipodal signals in non‐Gaussian noise modeled as a generalized normal‐Laplace (GNL) distribution combined with Gaussian noise is presented. The suboptimum receiver has low computational complexity. Furthermore, when the number of diversity branches is small, its performance is very close to that of the Neyman‐Pearson optimum receiver based on the probability density function obtained by the Fourier inversion of the characteristic function of the GNL‐plus‐Gaussian distribution.     

Wide‐Band Fine‐Resolution DCO with an Active Inductor and Three‐Step Coarse Tuning Loop

This paper presents a wide‐band fine‐resolution digitally controlled oscillator (DCO) with an active inductor using an automatic three‐step coarse and gain tuning loop. To control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. To cover the wide tuning range, a three‐step coarse tuning scheme is used. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. The DCO tuning range is 58% at 2.4 GHz, and the power consumption is 6.6 mW from a 1.2 V supply voltage. An effective frequency resolution is 0.14 kHz. The phase noise of the DCO output at 2.4 GHz is –120.67 dBc/Hz at 1 MHz offset.     

Microstrip Slow‐Wave Open‐Loop Resonator Filters with Reduced Size and Improved Stopband Characteristics

This paper presents a new class of microstrip slow‐wave open‐loop resonator filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends loaded with triangular and rectangular ends is described, leading to the invention of a microstrip slow‐wave open‐loop resonator. Two‐resonator and four‐resonator bandpass filters are designed at the operating frequency of about 2 GHz, and a bandwidth of 60 MHz. The size of the slow‐wave open‐loop resonator is optimized from the standpoint of the unloaded Q‐factor. The filters are not only compact in size due to the slow‐wave effect, but also have a wider upper stopband resulting from the dispersion effect. The filter designs of this type are described in details. The experimental results are demonstrated and discussed.