Low phase noise heterojunction bipolar transistor oscillator

A low phase noise, heterojunction bipolar transistor (HBT) oscillator has been designed and fabricated for operation at X-band. The common emitter oscillator employs a high-Q dielectric resonator as the parallel feedback element between the base and collector terminals. Series capacitive feedback is used in the emitter to enhance the oscillator's negative output impedance. Single-sideband FM noise levels of -76 dBc/Hz and -102 dBc/Hz have been achieved at 1 kHz and 10 kHz frequency offsets, respectively, for an 11.06 GHz carrier frequency. This is one of the lowest phase noise levels ever reported for an X-band solid-state transistor oscillator.<>     

X波段介质谐振器振荡器和缓冲放大器的研究

微波振荡器代表所有基本微波通信系统的能源来源。研究设计8．95GHz的低噪声砷化镓场效应管并联反馈介质谐振器振荡器,为了放大输出功率和提高负载牵引,在介质谐振器振荡器后一级加缓冲放大器,最终的输出功率是＋13．33dBm。测试证明输出信号的相位噪声偏离中心频率100kHz可达-116．49dBc／Hz,偏离中心频率10kHz可达-91．74dBc／Hz。     

A Ka-band micromachined low-phase-noise oscillator

A low-phase-noise 28.65 GHz oscillator has been demonstrated using a planar resonator. The resonator is micromachined close to the transistor and has an unloaded Q of 460. The oscillator uses a commercially available high electron mobility transistor (HEMT) for the active device, and results in an output power of 0.6 dBm with a 5.7% DC-RF efficiency. The measured phase noise is -92 dBc/Hz at a 100 kHz offset frequency and -122 dBc/Hz at 1 MHz offset frequency. This is compared with a low-Q planar design showing a 10 dB improvement in phase noise. The micromachined resonator is competitive with other hybrid nonplanar technologies, such as dielectric resonators     

A 22-GHz-band low-noise down-converter for satellite broadcastreceivers

A simple low-cost and high-performance 22 GHz band down-converter developed for a direct-to-home satellite broadcasting system is discussed. The down-converter consists of a low-noise high electron mobility transistor (HEMT) preamplifier, an image recovery mixer with a particular structure using dielectric resonator filters, a 21.4 GHz GaAs FET oscillator stabilized by a dielectric resonator, and an IF amplifier. These components are fully integrating using microwave integrated circuit technology into a small size. A total noise figure of less than 2.8 dB is obtained over the 22.5-23.0 GHz frequency range. The local oscillator achieves a frequency variation of less than 600 kHz_p-p over a temperature range of -20° to +60°C     

Low Phase-Noise Planar Oscillators Employing Elliptic-Response Bandpass Filters

In this paper, a low phase-noise planar oscillator employing an elliptic bandpass filter as a frequency stabilization element within its feedback loop is presented. The oscillator phase noise is significantly reduced by taking advantage of the group-delay peaks formed at the passband edges of the elliptic filter. A filter optimization technique for low phase-noise oscillator designs is introduced and applied to a four-pole bandpass elliptic filter. An $X$-band oscillator using the optimized filter in the feedback loop is designed and tested. At the oscillation frequency of 8.05 GHz, the measured phase noise is $-$143.5 dBc/Hz at 1-MHz offset frequency. The oscillator exhibits an output power of 3.5 dBm with an dc–RF efficiency of 10%. To the authors' best knowledge, this is the lowest phase noise performance for an $X$-band planar microwave oscillator.      

Design of a 5.305 GHz Dielectric Resonator Oscillator with Simulation and Optimization

The design of a 5.305 GHz series feedback free running dielectric resonator oscillator （DRO） is presented. Its simulation and optimization are realized by obtaining the unloaded Q factor of the cavity dielectric resonator （DR） and analyzing the linear and nonlinear models of the DRO. CAD packages of DR_Rez and Agilent Advance Design System （ADS） are used and the best tradeoff among the output power, phase noise, and frequency stability is achieved. With the result of simulation, a physical oscillator prototype is constructed. The measured results show the good agreement with those of simulation.     

Technique for Flicker Noise Up-Conversion Suppression in Differential LC Oscillators

A novel technique for the suppression of the flicker noise up-conversion in a differential LC oscillator topology is proposed. Relaxation mechanism and tunable noise filtering of the relaxation thresholds provide simultaneous suppression of differential pair and bias transistor flicker noise contributions. The proposed technique is validated on a fully monolithic oscillator architecture and 0.35-mum standard CMOS process by Cadence SpectreRF for the frequency range of 2.9-5.9 GHz. The phase noise improvement at 10 kHz offset versus a single-differential-pair LC oscillator is 6-15 dB across the tuning range.     

基于CST与ADS的介质谐振振荡器的设计

分析了介质谐振振荡器的起振和稳频的原理,研究了一种低相位噪声的介质谐振振荡器的设计方法。以X波段为例,利用CST Microwave Studio 2010软件仿真了微带线与介质谐振器耦合的模型,将仿真得到的结果导入S2P文件中。再利用Agilent ADS 2011软件仿真介质谐振振荡器的完整电路,采用S参数仿真和谐波仿真分析等方法设计介质谐振振荡器,结合理论分析,调整和修改实验电路的参数值,使模型达到最好的优化结果。最后通过测试验证仿真结果。采用NEC公司的2SC5508芯片作为放大器,得出微波振荡器的输出频率为10.6 GHz,输出功率为5.19 dBm和较低的相位噪声,其在偏离中心频率10 kHz处小于-121 dBc/Hz。     

A 0.5–2.5 GHz 910 uW complementary LNA employing positive–negative feedback

A 0.5–2.5 GHz ultra low power differential resistive feedback common gate low noise amplifier (RFCGLNA) without the use of inductor is presented. The proposed RFCGLNA adopts the NMOS and PMOS complementary topology to reduce the power consumption by half. Based on common-gate topology, the proposed RFCGLNA employs capacitive cross-coupling (CCC) and resistive feedback techniques. The CCC technique can further reduce the power consumption by half. The resistive feedback technique can constrain the common mode voltages of the proposed RFCGLNA and meanwhile, improve the third-order input intercept point (IIP3). The DC path is supplied by the current source transistor which forms a positive feedback loop to improve the gain at low frequency. Implemented with 65 nm standard complementary metal oxide semiconductor (CMOS) technology, the measured performance achieves 15 dB gain with S₁₁ < ?10 dB in the 0.5–2.5 GHz band. The noise figure (NF) is 3.9–5.0 dB and the IIP3 is 3.1–3.6 dBm. The power consumption is only 910 uW.     

A 20-GHz InP-HBT voltage-controlled oscillator with wide frequencytuning range

This paper presents the design and implementation of a 20-GHz-band differential voltage-controlled oscillator (VCO) using InP heterojunction-bipolar-transistor process technology. Aimed at 20- or 40-Gb/s fiber-optic applications, the design is based on a single-stage feedback amplifier with no intentional L or C. The salient features of the proposed VCO are wide frequency tuning range compared to LC oscillators, and low power consumption and transistor count compared to ring-oscillator counterparts. The implemented VCO has an adjustable frequency range from 13.75 to 21.5 GHz and provides two complementary outputs. Total power consumption at 18.6 GHz is 130 mW, while the phase noise is -90.0 dBc/Hz measured at 1-MHz offset frequency     

A Highly Stabilized GaAs FET Oscillator Using a Dielectric Resonator Feedback Circuit in 9-14 GHz

A new type of highly stabilized GaAs FET oscillator using a dielectric resonator and a stabilization resistor in the feedback circuit has been developed. The oscillator fabricated with a microwave integrated circuit has a high external quality factor Q/sub ex/ for more than1000 with no hysteresis phenomena. The microwave characteristics of the GaAs FET oscillator has revealed 1) high efficiency of 20 percent with 70-mW output power at 11.85 GHz, 2) a wide tuning range more than1000 MHz, 3) a wide oscillation frequency from 9 to 14 GHz with same MIC pattern by using five dielectric resonators of different sizes, 4) a high-frequency stability as low as /spl plusmn/ 150kHz in the tempature range from -20 to + 60/spl deg/ C, and 5) low FM noise of 0.07 Hz/ /spl radic/Hz at off-carrier frequency of 100kHz.     

S波段低相噪同轴介质压控振荡器设计

运用串联反馈振荡器理论设计了一个工作于S波段的低相噪同轴介质压控振荡器。首先分析了同轴介质谐振器的理论以及串联反馈振荡器的工作原理,然后在高频电磁仿真软件HFSS和ADS中进行仿真和设计。为了实现电调谐,将变容管合理地加入振荡器,最终设计完成了一个S波段的低相噪同轴介质压控振荡器。通过对实物成品的测量和调试表明,此压控振荡器达到了预定的技术指标,各项性能良好。测试结果:工作频率为2.075~2.250 GHz,调谐范围为1.75 GHz,输出功率≥11 dBm,谐波抑制度≥23 dBc,相位噪声优于-133 dBc/Hz@100kHz。     

Tunable magnetostatic-wave oscillator employing a single GaAs MMIC chip

A microwave tunable magnetostatic surface-wave delay-line oscillator which employs a single GaAs monolithic amplifier chip in the feedback loop has been developed. No directional coupler is needed, and a single-mode oscillation can be tuned continuously from 4.82 to 6.39 GHz without frequency jumping. At 6.1 GHz, an output power of 4.4 dBm was measured with a phase noise of -100 dBc/Hc at 10 kHz offset from the oscillation frequency.<>     

基于高次谐波体声波谐振器的微波振荡器设计

基于高次谐波体声波谐振器(HBAR)的高品质因数(Q)值和多模谐振特性,设计了Colpitts和Pierce两种形式的微波振荡器。采用HBAR与LC元件组成谐振回路的方法,与放大电路构成反馈环路直接基频输出微波频段信号。Colpitts振荡器输出信号频率为980 MHz,信号输出功率为-4.92dBm,信号相位噪声达-119.64dBc/Hz@10kHz;Pierce振荡电路输出信号频率达到2.962GHz,信号输出功率为-9.77dBm,信号相位噪声达-112.30dBc/Hz@10kHz。     

A Highly Stabilized Low-Noise GaAs FET Integrated Oscillator with a Dielectric Resonator in the C Band

A GaAs FET integrated oscillator stabilized with a BaO--TiO/sub 2/ system ceramic dielectric resonator provides a high-frequency-stabilized low-noise compact microwave power source. The newly developed ceramic has an expansion coefficient and dielectric constant temperature coefficient that offset each other and result in a small resonant frequency temperature coefficient. A stabilized oscillator output of 100 mW with a 17-percent efficiency and a frequency temperature coefficient as low as 2.3 ppm//spl deg/C are obtained at 6 GHz. FM noise level is reduced more the 30 dB by the stabilization. The dynamic properties of the oscillator and resonator are precisely measured to determine equivalent circuit representations. A large-signal design theory based on these equivalent circuit representations is presented to realize the optimal coupling condition between the oscillator and stabilizing resonator. The stabilized oscillator performance is sufficient for application to microwave communications systems.     

A 25-GHz ultra-low phase noise InGaP/GaAs HBT VCO

A 25-GHz monolithic voltage controlled oscillator (VCO) has been designed and fabricated in a commercial InGaP/GaAs heterojunction bipolar transistor (HBT) process. This balanced VCO has a novel topology using a feedback /spl pi/-network and a common-emitter transistor configuration. Ultra-low phase noise is achieved: -106 dBc/Hz and -130 dBc/Hz at 100kHz and 1-MHz offset frequency, respectively. To the authors' knowledge, this is the lowest phase noise achieved in a monolithic microwave integrated circuit (MMIC) VCO at such high frequency. The single-ended output power is -1 dBm. It can be tuned between 25.33GHz and 25.75GHz using the base-collector junction capacitor of the HBT as a varactor. The dc power consumption is 90mW for a 9-V supply. An excellent figure-of-merit of -195 dBc/Hz is obtained.     

Balanced Colpitt oscillator MMICs designed for ultra-low phase noise

Balanced voltage-controlled oscillator (VCO) monolithic microwave integrated circuits (MMICs) based on a coupled Colpitt topology with a fully integrated tank are presented utilizing SiGe heterojunction bipolar transistor (HBT) and InGaP/GaAs HBT technologies. Minimum phase noise is obtained for all designs by optimization of the tank circuit including the varactor, maximizing the tank amplitude, and designing the VCO for Class C operation. Fundamental and second harmonic VCOs are evaluated. A minimum phase noise of less than -112 dBc at an output power of 5.5 dBm is achieved at 100-kHz carrier offset and 6.4-GHz oscillation frequency for the fundamental InGaP/GaAs HBT VCO. The second harmonic VCO achieves a minimum measured phase noise of -120 dBc at 100 kHz at 13 GHz. To our best knowledge, this is the lowest reported phase noise to date for a varactor-based VCO with a fully integrated tank. The fundamental frequency SiGe HBT oscillator achieves a phase noise of -108 dBc at 100 kHz at 5 GHz. All MMICs are fabricated in commercial foundry MMIC processes.     

低相噪启钥式耦合微波光电振荡器研究北大核心

针对微波通信、雷达、电子战和导航等先进电子系统的应用发展需求,为了实现具有实用价值的极低相噪耦合微波光电振荡信号产生,提出了一种基于Sigma型光纤储能环腔架构的低相噪启钥式耦合微波光电振荡器。该方案通过Sigma型光纤储能技术消除了耦合微波光电振荡器中存在的偏振衰落问题,并且通过有源光纤环腔再生增益特性极大增强了振荡器品质因数,最终实现了10 GHz耦合微波光电振荡器的开机启钥稳定运行,起振信号在10 kHz频偏处的相位噪声达到-139.26 dBc/Hz。     

5～10 GHz MMIC低噪声放大器

采用稳懋公司150 nm GaAs赝配高电子迁移率晶体管(PHEMT)工艺,设计了一款5 ～ 10 GHz单片微波集成电路(MMIC)低噪声放大器(LNA).该LNA采用三级级联结构,且每一级采用相同的偏压条件,电路的低频工作端依靠电容反馈,高频工作端依靠电阻反馈调节阻抗匹配,从而实现宽带匹配,芯片面积为2.5 mm×1 mm.测试结果表明,工作频率为5～10 GHz,漏极电压为2.3V,工作电流为70 mA时,LNA的功率增益达到35 dB,平均噪声温度为82 K,在90％工作频段内输入输出回波损耗优于-15 dB,1 dB压缩点输出功率为10.3 dBm,仿真结果与实验结果具有很好的一致性.     

Quasi-planar K-band push-push low phase noise oscillator stabilized by cavity resonator

The results of developing a K-band (24 GHz) push-push low phase noise transistor oscillator have been presented. This oscillator is stabilized by a rectangular resonant metallic cavity. The power level of output signal is ?9.5 dBm, the fundamental harmonic suppression is 21 dB. Single sideband (SSB) phase noise spectral density of ?98 dBc/Hz at 10 kHz and ?128 dBc/Hz at 100 kHz offset from the carrier frequency is at the level of dielectric resonator oscillators (DRO) scaled to the same frequency. The oscillator features a compact size, low cost quazi-planar design and it is built using commercially available off the shelf parts.