压控振荡器(VCO)技术综述文献翻译

压控振荡器（VCO）技术综述 1. 前言

压控振荡器(voltage-controlled oscillator, VCO) 是一种以电压输入来用来控制振荡频率的电子振荡电路,是现代无线电通信系统的重要组成部分课题。在当今集成电路向尺寸更小、频率更高、功耗更少、价格更低发展的趋势下，应用标准工艺设计生产高性能的压控振荡器已是射频集成电路中的一个重要课题。环形振荡器易于集成，可调频率范围大，但相位噪声不如性能不如LC振荡器。LC压控振荡器要求高品质因素的无源器件，需要片上电感和变容管器件才能集成集成。

振荡器自其诞生以来就一直在通信、电子、航海航空航天及医学等领域扮演重要的角色，具有广泛的用途。在无线电技术发展的初期，它就在发射机中用来产生高频载波电压，在超外差接收机中用作本机振荡器，成为发射和接收设备的基本部件。随着电子技术的迅速发展，振荡器的用途也越来越广泛，例如在无线电测量仪器中，它产生各种频段的正弦信号电压:在热加工、热处理、超声波加工和某些医疗设备中，它产生大功率的高频电能对负载加热;某些电气设备用振荡器做成的无触点开关进行控制;电子钟和电子手表中采用频率稳定度很高的振荡电路作为定时部件等。尤其在通信系统电路中，压控振荡器(VCO)是其关键部件，特别是在锁相环电路、时钟恢复电路和频率综合器电路等更是重中之重，可以毫不夸张地说在电子通信技术领域，VCO几乎与电流源和运放具有同等重要地位。

2. 主题

2.1 VCO的发展过程

上世纪初，Armstrong发明了电子管振荡器，经Hartley改进电路设计并开发成功电

子管VCO。电子管VCO的振荡频率是通过改变振荡电路中电感器或电容器的参数值来进行调节。当时人们对电子管振荡电路开展了大量的研究，今天仍在沿用的Hartley，Colpitts，Clapp，Armstrong，Pierce等经典振荡电路结构，就是当时的研究成果。

上世纪中叶，晶体管问世并很快取代电子管成为振荡电路的有源器件。特别是变容二极管的应用对VCO的发展具有重要意义。变容二极管的电容随外加电压的改变而变化，用变容二极管作压控器件，改变其控制电压就可实现VCO振荡频率的调节。这样，晶体管、变容二极管和其他无源元件就构成了分立式的晶体管VCO。这种晶体管VCO实现了振荡频率的电子调谐，这是变容二极管对VCO发展的重大贡献。与电子管VCO相比较，晶体管VCO具有电子调谐、体积小、成本低、功耗小、质量好、调频范围设置简便等优点。晶体管VCO的发展也是是电视技术能在当时迅速推广的重要原因。1960年至1980年，晶体管VCO被电子系统设计所广泛采用。到了1980年，情况发生了变化，混合集成的VCO组件和单片集成的VCO IC出现了。这两种新技术对VC0的发展产生了重要的影响。VCO从此就开始步入现代VCO技术的发展时期。各种VCO技术的寿命期与时间的关系示于图l。该图简要地说明了VCO技术在过去80多年里的发展历程。

图1 各种VCO技术寿命期

变容二极管、电容器、电感器等元器件的小型化为制造VCO组件创造了条件。VCO

组件是一种混合集成电路器件，具有封装和外引线。虽然分立元件的晶体管VCO具有按用户要求设计工作频率和调谐范围的灵活性，但一般在生产中都需要耗费大量的人工对确定频率的元件进行调试，以消除元件误差对频率的影响。此外，分立元件VCO需要良好的屏蔽，其尺寸也比较大。分立元件的VCO已不能完全满足现代无线电子系统发展的要求。

20世纪80年代末、90年代初，移动电话迅速发展，对带封装的振荡器组件的需求也日益增长。这为VCO组件的发展提供了难得的市场机遇。随着新型无线应用领域的不断发展，各VCO组件厂商开发了适合不同应用领域所需频率的产品。由于表面安装元件的不断小型化(1206，0805，0603，0402和0201)，新开发的VCO组件的尺寸也越来越小，成本也越来越低。图2说明了现代商用VCO组件尺寸随时间减小的变化情况。目前，VCO组件达到了新的水平，其体积已减小到4 mm×5mm×2mm，大批量供货VCO的销售单价已降至1美元左右。VCO组件在15年中其尺寸急剧减小，满足了蜂窝电话等新型无线移动装置对小型化的要求。

VCO组件体积变化过程图2

20世纪90年代末期，出现了一种尺寸更小、成本更低的VCO技术，这就是单片集成VCO技术。单片集成VCO是一种半导体集成电路器件，其全部电路元件均集成在同一芯片上。这种器件像VCO组件一样，是一个完整的VCO，具有封装和外引线。首批单片集成VCO采用2英寸GaAs IC工艺和单片微波集成电路(MMIC)技术制造，是为卫星接收

机和雷达系统研制的。其工作频率高达数GHz，但成本高昂。大多数早期单片GaAs VCO的研究工作都是针对军事应用展开的，很少涉及民用领域。在20世纪80年代，Si-IC技术还是一种低频技术，不能为单片集成VCO提供上千兆赫兹的工作频率和所需的带宽。

经过研究与开发，1990年Si-IC技术在高频化和无源元件集成方面获得重大进展，开发成功工作频率很高的晶体管、变容二极管和单片集成的高Q值电感器与高频电容器。这为高频硅单片集成VCO的研究与开发奠定了技术基础。无线移动通信系统的发展，要求大批量提供成本低、体积小、工作在800～2500MHz频段的VCO。人们为此开展了大量的研究与开发工作。1992年，美国California大学首先报道了硅单片VCO IC的研究成果。其后，对硅单片VCO IC的研究进入繁荣期，采用不同技术方案的硅单片VCO IC相续问世。

硅单片VCO IC由高频双极晶体管IC技术和SiCMOS-IC技术研制而成。在硅单片VCO IC的研制过程中，学术研究机构通常采用获得广泛应用的SiCMOS-IC技术，而工业界则采用RFIC专用的BiCMOS技术。硅单片集成VCO体积更小、成本更低并适合大批量生产的产品，而且可以采用RF收发前端的工艺技术进行制造。这表明，VCO可以与混频器、低噪声放大器、锁相环等其他RF收发前端的功能电路模块实现集成。正是由于VCO IC具备这些潜在的优势，尽管早期产品性能欠佳，但人们对它的研究工作一直没有停顿。通过不断改进，其产品已广泛应用于无绳电话、蓝牙装置、WLAN、GPS、DBS等无线装置与系统之中。表1列出了一些单片集成VCO的应用实例。

表1 含有单片集成VCO的商用RFIC实例

目前，单片集成VCO还不能用于对相位噪声要求很高的应用领域。像GSM、CDMA等具有高数据速率的移动电话系统，还只能使用VCO组件。

2.2 VCO技术的发展趋势

今后，VCO技术的研究与开发工作将继续围绕VCO组件和单片集成VCO展开。但是，全集成单片VCO技术是研究工作的重点，也是未来VCO技的发展方向为了适应现代无线系统发展的要求，VCO组件不断向小型、高频、宽带、高输出化和特性多样化方向发展。将采用新的超小型元件和更先进的薄膜技术与表面安装技术，继续推进VCO组件封装的微型化和表面安装化。通过晶体管的改进及振荡电路的开发，解决好小型化带来的谐振器Q值降低的问题和低功耗引起的特性劣化问题。移动电话以及其他工作在微波频段高端的无线系统需要VCO组件进一步提高工作频率，实现VCO组件高频化。开发工作频率更高的微波VCO组件是未来十分重要的研究课题。

SiGe BiCMOS等RF IC基础工艺技术正在不断发展与进步。半导体工艺制造有源器件与无源器件将具有更好的性能。现在，即使用Si工艺技术，也可制得 超过50GHZ的晶体管和高Q值，大电容变比，低串联电阻的优质便容二极管。这类工艺技术还具有衬底损耗低，金属化层厚，器件寄生元件少，工作频率高，工作电流小的单片集成VCO。

现代无线系统，尤其是现代无线移动通信系统，不仅要求VCO自身小型化和低成本化，而且希望VCO能同频率合成器与收发机的其他单元电路进行单片集成，以达到减少整机体积和成本的目的。此外，单片集成VCO的设计理论也在深化，设计技术也越来越先进。差分放大器，幅度控制，二次谐波抑制器，IC耦合变压器，复合振荡器，高频结构设计等技术正不断被纳入单片集成VCO的设计之中。利用单片集成VCO技术把优质VCO同收发机电路集成在一起的新产品不断问世。例如在WLAN和蓝牙装置中，最新的收发机就把高质量的VCO同RF收发前端IC集成在一起，使其尺寸大大减小。 WLAN系统（2.4GHZ 802.11b型和5GHZ 802.11a型）要求VCO具有很低的相位噪声。

由于RF IC VCO技术的不断发展，卫星接收机，CATV机顶盒，无线数据装置，无绳电话，移动电话等商用RF系统与装置越来越多地采用集成化频率源。显然，在大规模商业应用领域中，单片集成VCO占有的市场份额将不断增大，而分立元件VCO和VCO组件占有市场将逐步减小。单片集成VCO在大规模商用无线系统中占主导地位的时代很快就会到来。VCO技术已经实现了从笨重的电电子管VCO电路到面积小于1平方毫米Si IC的跨越。

3. 总结

VCO是频率源的关键器件，已广泛应用于各种电子系统之中。VCO的性能对电子系统有决定性的影响。现代无线移动通信系统的发展促进VCO高频化，形成了新一代微波VCO。VCO组件和单片集成VCO是微波VCO的主要结构形式，是目前无线系统采用的主流产品。虽然，在总体性能水平方面，单片集成VCO目前还不如VCO组件好，但它具

有集成优势，仍然是VCO未来发展的方向。在RF IC工艺技术中，SiGe BiCMOS技术是单片集成VCO最有前途的制造技术。

摘自：ISO/IEC JTC1/SC29/WG1 (ITU-SG8) N2058, \"JPEG2000 is now an International Standard\

voltage controlled oscillator

1 Preface

Voltage controlled oscillator ( voltage-controlled oscillator, VCO ) is a kind of voltage input to control the oscillation frequency of the oscillating circuit, is a modern radio communication system is an important part of task [1] [2]. In the integrated circuit to the smaller size, less power consumption, higher frequency, lower price trends, application standard process design and production of high performance voltage controlled oscillator RF integrated circuit is an important subject in the. The ring oscillator is easy to be integrated, the adjustable frequency range, but better performance than LC oscillator phase noise. LC VCO

requirements quality factors of passive devices, need the on-chip inductor and varactor devices to integrate [3].

Oscillator since its birth has been in communication, electronics, aerospace and other fields of medicine navigation plays an important role, has a wide range of uses. In radio technology in the initial stage of development, it is in the transmitter to generate high frequency carrier wave voltage, the heterodyne receiver is used as a local oscillator, a transmitting and receiving equipment basic

components. With the rapid development of electronic technology, the oscillator uses more and more widely, for example in radio measurement instruments, it produces various frequency sinusoidal signal voltage: in the heat processing, heat treatment, ultrasonic machining and some medical equipment, it produces high power high frequency electric power of load heating; some electrical equipment oscillator. The contactless switch control; electronic clock and electronic watches using frequency stability high oscillation circuit as a timing component. Especially in the communication system circuit, a voltage controlled oscillator ( VCO ) is one of the key parts, especially in the phase-locked loop circuit, clock recovery circuit and frequency synthesizer circuit is Chongzhongzhi is heavy, it is no exaggeration to say in electronic communication technology, VCO almost with the current source and the operational amplifier has the same important position.

2.theme

2.1The development of 1.VCO process

At the beginning of the last century, Armstrong invented electronic oscillator, the improved Hartley circuit design and the successful development of VCO tube. Electronic tube VCO oscillation frequency is changed by the oscillation circuit inductor or capacitor parameter values to adjust. At that time the people to the electronic tube oscillation circuit to carry out a great deal of research, today is still in use in the Hartley, Colpitts, Clapp, Armstrong, Pierce and other classical oscillating circuit structure, was the research results.

The middle of the last century, the first transistor and quickly replace the tube

becomes oscillatory circuit of the active device. In particular the varactor applications on the VCO has important significance to the development of. Variable capacitance diode capacitance as a function of the applied voltage change, using varactor diode voltage controlled device, change the control voltage can be achieved VCO oscillation frequency regulation. In this way, the transistor, varactor diodes and other passive components form the vertical transistor VCO. This transistor VCO implementation of the oscillation frequency of the electronic tuning varactor diode, it is the significant contribution of VCO development. Electronic tube with VCO compared to VCO, transistor with electronic tuning, small volume, low cost, small power consumption, good quality, easy FM range setting. Transistor VCO is the development of television technology at that time rapid promotion of important reasons. From 1960 to1980, VCO transistors are widely used in electronic system design. By 1980, the situation has changed, hybrid integrated VCO module and monolithic integrated VCO IC appeared. These two kinds of new technology to the development of VC0has produced important influence. VCO has started to enter the modern VCO technology development period. A variety of VCO technology life cycle and the time relation shown in Figure L. The graph, a brief description of the VCO technology in the past 80 years development course.

Fig 1VCO technology life cycle

Variable capacitance diodes, capacitors, inductors and other components of the miniaturization for the manufacture of VCO components to create the conditions. VCO component is a hybrid integrated circuit device, a package and the outer lead wires. Although discrete transistor VCO according to user

requirements with the design and operating frequency tuning range and flexibility, but generally in the production need to consume a large amount of artificial to determine the frequency components for debugging, in order to eliminate the element error on the frequency effect. In addition, discrete components VCO needs good shielding, its size is relatively large. Discrete element VCO can not satisfy the requirements of the development of modern wireless electronic system.

At the end of nineteen eighties, the early 90's, the rapid development of the mobile phone, with a package of oscillator components growing demand. This is a VCO component development offerred rare market opportunity. Along with the new wireless application development, each VCO component manufacturers developed for different applications in the field of desired frequency products. Due to the small surface mount components (1206080506030402 and0201), the

new development of the VCO component size is more and more small, cost more and more low. Figure 2 illustrates the modern commercial VCO component size with reduced variation. At present, the VCO component has reached a new level, its volume is reduced to 4mm * 5mm * 2mm, supply large quantities VCO sales price has dropped to about $1. VCO component in the15 years of its size reduced sharply, to meet the new wireless mobile devices such as cellular phones on the miniaturization requirement.

The VCO component volume change process of2

Nineteen ninties stage, the emergence of a smaller size, lower cost of the VCO technology, which is monolithically integrated VCO technology. Monolithic integrated VCO is a semiconductor integrated circuit device, all the circuit

components are integrated on the same chip. This device like the VCO module, is a complete VCO, with packaging and outer lead. The first batch of monolithic integrated VCO uses 2 inches of GaAs IC technology and the monolithic microwave integrated circuit ( MMIC ) manufacturing technology, is for the satellite receiver and radar system. Its high working frequency of GHz, but the high cost. Most of the early single GaAs VCO 's research work is aimed at the military application of unfolding, rarely involved in civil field. In the nineteen eighties, Si-IC

technology is a kind of low frequency technology, not for the monolithic integrated VCO with Giga Hertz frequency and bandwidth required for.

Through research and development, in 1990 the Si-IC technique in high frequency and passive components integration has achieved significant progress, the successful development of the work with very high frequency transistor, variable capacitance diode and monolithic integration of high Q value of the inductor and the high frequency capacitor. The high frequency silicon monolithic integrated VCO research and development laid a technological basis. Wireless mobile communication system development, requirements in large quantities to provide low cost, small volume, work in the 800 ~2500MHz band VCO. It carried out a great deal of research and development work. In 1992, American California University was first reported by Silicon Monolithic VCO IC research. Thereafter, the silicon monolithic VCO IC research to enter prosperous period, using different techniques for Silicon Monolithic VCO IC continued publication.

Silicon Monolithic VCO IC by high frequency bipolar transistor IC technology and SiCMOS-IC technology developed by. In Silicon Monolithic VCO IC

development process, academic and research institutions usually adopt the widely used SiCMOS-IC technology, while the industry is using RFIC special BiCMOS technology. Silicon monolithic integrated VCO smaller volume, lower cost and suitable for mass production of products, but also can be used to RF front-end technology manufacturing. This shows, VCO can be associated with a mixer, low noise amplifier, phase locked loop and other RF front-end circuit function module to realize the integrated. It is because the VCO IC with these potential advantages, although early products of poor performance, but the research work has not

stopped. Through continuous improvement, its products have been widely used in cordless phones, Bluetooth devices, WLAN, GPS, DBS and other wireless devices and systems. Table 1 lists some monolithic integrated VCO application examples [4].

Table 1 contains monolithic integrated VCO RFIC commercial examples At present, monolithic integrated VCO also cannot be used for phase noise of demanding applications. Like GSM, CDMA has a high data rate mobile phone system, also can use VCO components

2.2The development trend of 2.VCO Technology

In the future, VCO technology research and development work will continue to focus on VCO components and monolithic integrated VCO expansion. However, the monolithic integrated VCO technology is the research focus, but also the future of VCO technology development direction in order to adapt to modern wireless system development requirements, VCO components to small, high frequency, wide band, high output and characteristic development. We will adopt a new miniature components and more advanced thin film technology and surface mount technology, continue to promote the VCO package miniaturization and

mounted on the surface of. The pass transistor oscillation circuit improvement and development, solve good miniaturization brings resonator Q reduces problems and low power consumption caused by deterioration of a problem. Fourth generation mobile phones and other work in the microwave band high-end wireless systems need to further improve the working frequency of the VCO component, VCO component high frequency. Development of frequency higher microwave VCO components are very important research topic in the future.

SiGe BiCMOS RF IC basic technology is evolving with progress. Semiconductor manufacturing technology of active devices and passive components will have better performance. Now, using the Si technology, also can be used for more than 50GHZ transistors and high Q value, high capacitance ratio, low series resistance and capacitance diode quality. This technology also has a substrate of low loss, metal layer thickness of parasitic element, device is little, high working frequency, small working current monolithic integrated VCO.

Modern wireless systems, especially in modern mobile communication system, not only requires the VCO its miniaturization and low cost, but also hope that VCO with frequency synthesizer and transceiver unit circuits are monolithically integrated, so as to reduce the volume and cost of the. In addition, monolithic integrated VCO design theory also is being deepened, more and more advanced design technology. Differential amplifier, amplitude control, two harmonic suppressor, IC coupling transformer, composite oscillator, high frequency structure design technology are being incorporated into the monolithic integrated VCO design. Using monolithic integrated VCO technology to high-quality VCO transceiver circuit integrated together with the new products continue to come

out. For example, in WLAN and Bluetooth device, the new transceiver is made of high quality VCO and RF transceiver front-end IC integrated together, so that its size is greatly reduced. WLAN (2.4GHZ802.11b type and 5GHZ type 802.11a ) called VCO has very low phase noise.

Because RF IC VCO technology unceasing development, satellite receiver, CATV set-top box, wireless data device, cordless phones, mobile phones and other commercial RF systems and devices are increasingly used integrated frequency source. Obviously, in large-scale commercial application, monolithic integrated VCO market share will continue to increase, and the discrete component VCO and VCO components of market share will be reduced stage by stage. Monolithic integrated VCO in large-scale commercial wireless system is dominated by the time will soon come. VCO technology has realized from the heavy electric tube VCO circuit to the area less than 1square mm Si IC span.

3.summary

VCO is the key device of frequency source, has been widely used in various electronic systems. The performance of VCO has a decisive effect on electronic system. In modern mobile communication system to promote the development of VCO high frequency, to form a new generation of microwave VCO. The VCO components and VCO microwave monolithic integrated VCO is a main structural form, is currently the mainstream product of wireless system. Although, in the overall performance levels, monolithic integrated VCO is inferior to VCO component, but it has the integrated advantage, VCO still is the developing direction in the future [5]. In the RF IC technology, SiGe BiCMOS technology is a

monolithic integrated VCO the most promising manufacturing technology.