Design of a negative conductance dielectric resonator oscillator for X-band applications

An X-band tunable microwave low-phase noise planar oscillator employing a novel-fed dielectric resonator (DR) with a single transistor has been investigated and realized. A ZrSnTi oxide composite ceramic-based DR with dielectric permittivity of 95 enclosed in a metallic cavity with an unloaded Q factor of 5,000 at 10 GHz is proposed. The resonant frequency affinity with respect to geometric parameters is established by using the compensation technique based on dual negative conductance feedback, the outputs of which are combined via a Wilkinson power divider (WPD). The feedback parallel-coupled DR oscillator is incorporated into a laminate microwave board using the photolithographic technique. The oscillator includes a pseudomorphic low noise amplifier based on a high-electron-mobility transistor. Hence, the proposed oscillator with mechanic tuning is measured, and the results show that DR resonates at TE _01δ mode with frequency of 10 GHz. The measured phase noise of the oscillator is –81.03 dBc/Hz at a 100 kHz offset.     

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.     

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     

一个8GHz高功率AlGaN/GaN HEMT VCO

基于中科院微电子所的AlGaN/GaN HEMT工艺研制了一个X波段高功率混合集成压控振荡器（VCO）。电路采用源端调谐的负阻型结构,主谐振腔由开路微带和短路微带并联构成,实现高Q值设计。在偏置条件为VD=20V, VG=-1.9V, ID=150mA时,VCO在中心频率8.15 GHz处输出功率达到28 dBm,效率21%,相位噪声-85 dBc/Hz@100 KHz,-128 dBc/Hz@1 MHz。调谐电压0~5V时,调谐范围50 MHz。分析了器件闪烁噪声对GaN HEMT基振荡器相位噪声性能的主导作用。测试结果显示了AlGaN/GaN HEMT工艺在高功率低噪声微波频率源中的应用前景。     

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.     

Noise property of a quadrature balanced VCO

A quadrature balanced voltage controlled oscillator (B-VCO) with current source switching is proposed and analyzed. This letter shows analytically that the switching improves the phase noise. A switched transistor is also used as a coupling transistor to generate quadrature signals without degrading the phase noise. To investigate the effect of quadrature coupling on the phase noise, a single B-VCO and a quadrature B-VCO are implemented with identical components in an 0.18-/spl mu/m CMOS process. Both VCO cores draw about 8.8mA under a low bias voltage of 1.8V. The oscillation frequencies are 10.21GHz and 10.81GHz. The measured phase noises of the single at an offset frequency of 1MHz VCO is -114.83 dBc/Hz while that of the quadrature VCO is -116.67 dBc/Hz. The quadrature B-VCO is superior to the single B-VCO with respect to phase noise and oscillation frequency in the X-band.     

An 8 GHz high power AlGaN/GaN HEMT VCO

A high power X-band hybrid microwave integrated voltage controlled oscillator(VCO) based on Al-GaN /GaN HEMT is presented.The oscillator design utilizes a common-gate negative resistance structure with open and short-circuit stub microstrip lines as the main resonator for a high Q factor.The VCO operating at 20 V drain bias and-1.9 V gate bias exhibits an output power of 28 dBm at the center frequency of 8.15 GHz with an efficiency of 21%.Phase noise is estimated to be -85 dBc/Hz at 100 kHz offset and -1...     

射频MEMS封装振荡器的稳定性研究

文章介绍了一种由MEMS圆盘谐振器和低噪声反馈电路构成的射频振荡器。MEMS谐振器具备高Q值,使得振荡器表现出良好的频率稳定性和低相位噪声。采用低成本的金锡键合工艺对双端口谐振器封装后,进一步提升了频率稳定性。低噪声电路由两级放大组成,在提供足够增益的情况下,提升了相位噪声性能。之后测试得到的相位噪声分别是在1 kHz 频偏处为-96 dBc/Hz,噪底 -128 dBc/Hz 。中期稳定性和阿伦方差的测试结果分别为±4 ppm和10 ppb。这些结果均表明,该振荡器在新一代无线通信中有广阔的应用前景。     

Cavity coupling structure for planar oscillators showing DR-likereflective characteristics

A new cavity coupling structure has been developed for low-phase noise oscillator applications. Unlike the conventional cavity coupling structures that show absorption at the resonant frequency, the new structure shows high reflection at resonance similar to dielectric resonators, making it suitable for the reflective oscillators. The fabricated cavity resonator showed a loaded Q-factor of 1200 and the X-band oscillator using the new resonator showed phase noise proper-ties of -57 and -83 dBc/Hz at 1 and 10 kHz offset, respectively. This is comparable to the best results of dielectric resonator oscillators using HEMTs at this frequency range     

A Low Phase-Noise X-Band MMIC VCO Using High-Linearity and Low-Noise Composite-Channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN HEMTs

A low phase-noise X-band monolithic-microwave integrated-circuit voltage-controlled oscillator (VCO) based on a novel high-linearity and low-noise composite-channel Al_0.3Ga_0.7N/Al_0.05Ga_0.95 N/GaN high electron mobility transistor (HEMT) is presented. The HEMT has a 1 mumtimes100 mum gate. A planar inter-digitated metal-semiconductor-metal varactor is used to tune the VCO's frequency. The polyimide dielectric layer is inserted between a metal and GaN buffer to improve the Q factor of spiral inductors. The VCO exhibits a frequency tuning range from 9.11 to 9.55 GHz with the varactor's voltage from 4 to 6 V, an average output power of 3.3 dBm, and an average efficiency of 7% at a gate bias of -3 V and a drain bias of 5 V. The measured phase noise is -82 dBc/Hz and -110 dBc/Hz at offsets of 100 kHz and 1 MHz at a varactor's voltage (V_tune)=5 V. The phase noise is the lowest reported thus far in VCOs made of GaN-based HEMTs. In addition, the VCO also exhibits the minimum second harmonic suppression of 47 dBc. The chip size is 1.2times1.05 mm²     

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。     

An X‐Band Carbon‐Doped InGaP/GaAs Heterojunction Bipolar Transistor MMIC Oscillator

This paper addresses a fully‐integrated low phase noise X‐band oscillator fabricated using a carbon‐doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves ?127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X‐band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a 0.8 mm × 0.8 mm die area.     

基于基片集成波导谐振器的压控振荡器设计

设计了一种基于基片集成波导谐振器的X波段压控振荡器。首先分析了串联反馈式振荡器以及基片集成波导谐振器的理论,然后在高频电磁仿真软件ADS中进行仿真和设计,并通过将变容管合理地引入谐振器,实现了电调谐的目的。最终设计完成了一个工作于X波段的基片集成波导压控振荡器。此压控振荡器与传统的介质压控振荡器(DRO)相比,具有稳定性高、平面化以及成本低的优点。由于采用了ADS中的联合仿真功能进行振荡器的设计,仿真结果的准确性得到了提高,减小了实物的调试工作量。测试结果为:工作频率为7 GHz,调谐范围为30 MHz,输出功率≥7 dBm,谐波抑制度≥22 dBc,相位噪声优于-106 dBc/Hz@100 kHz。     

Low phase noise IP VCO for multistandard communication using a 0.35-/spl mu/m BiCMOS SiGe technology

In this letter, we report that a commonly used 0.35-/spl mu/m, 60-GHz-F/sub MAX/ BiCMOS SiGe monolithic microwave integrated circuit (MMIC) technology is able to provide very low phase noise signal generation in the X-band frequency range. This statement has been demonstrated using a differential LC voltage-controlled oscillator (VCO) in which varactors are realized with metal-oxide semiconductor (MOS) transistors and inductors with a patterned ground shield technology. This VCO features an output power signal in the range of -5 dBm and exhibits a phase noise of -96 dBc/Hz at a frequency offset of 100kHz from carrier and -120 dBc/Hz at a frequency offset of 1 MHz. The VCO features a tuning range of 430 MHz or 4.3% of its operating frequency. Its power consumption is in the range of 70 mW (200 mW with buffers circuits) for a chip size of 800/spl times/1000 /spl mu/m/sup 2/ (including RF probe pads).     

推–推振荡器共用谐振器分析与低相位噪声设计

为实现低相位噪声平面振荡器,对推-推振荡器的共用谐振器与相位噪声优化方法进行了研究。提出一种基于多环式开口谐振环的差分传输线,通过加载一对耦合谐振环的方式实现2个单元振荡器之间的弱耦合,提高了共用谐振器的频率选择特性。基于该结构设计并实现了一种X波段推-推振荡器,在设计中采用一种基于振荡器有源品质因子的相位噪声优化方法。测试结果表明：该振荡器在输出二次谐波9.52 GHz处的相位噪声为-115.48 dBc/Hz@100 kHz,基波抑制度达到-54.55 dBc。     

A low-noise K-Ka band oscillator AlGaAs/GaAsheterojunction bipolar transistors

The design considerations, fabrication process, and performance of the first K-Ka-band oscillator implemented using a self-aligned AlGaAs/GaAs heterojunction bipolar transistor (HBT) are described. A large-signal time-domain-based design approach has been used which applies a SPICE-F simulator for optimization of the oscillator circuit parameters for maximum output power. The oscillator employs a 2×10-μm² emitter AlGaAs/GaAs HBT that was fabricated using a pattern inversion technology. The HBT has a base current 1/f noise power density lower than 1×10^-20 A²/Hz at 1 kHz and lower than 1×10^-22 A/²/Hz at 100 kHz for a collector current of 1 mA. The oscillator, which is composed of only low-Q microstrip transmission lines, has a phase noise of -80 dBc/Hz at 100 kHz off carrier when operated at 26.6 GHz. These results indicate the applicability of the HBTs to low-phase-noise monolithic oscillators at microwave and millimeter-wave frequencies, where both Si bipolar transistors and GaAs FETs are absent     

Small-Size X-Band Active Integrated Antenna With Feedback Loop

A small-sized active integrated antenna (AIA), consisting of a transmission feedback oscillator loaded with a microstrip antenna is presented in this paper. The oscillator antenna, which consists of a NEC super low noise high frequency field effect transistor (HF FET) integrated into the center of a segmented patch antenna, was designed for X-band at 8.50 GHz, and occupies a 5 times 6 mm² area. The active integrated antenna demonstrates stable oscillations and excellent radiation patterns at X-band design frequencies. When biased using a single 1.5 volt battery connected between the source and drain and with the gate terminal open, the antenna effective isotropic radiated power (EIRP) and direct current (DC)-to-radiated radio frequency (RF) conversion efficiency are +11.2 dBm and 10.5%, respectively. The radiated power level and directivity are +4.5 dBm and 6.7 dBi, respectively. The phase noise at 100 kHz offset from the carrier is -87.5 dBc/Hz, which is a notable improvement over existing AIA designs. The AIA features compact size and simple geometry, yet provides radiated power levels and radiation efficiencies that are comparable to values typically obtained using circuits that occupy larger areas, and use thicker substrates with much lower dielectric constant values.     

基于Phase-Refining技术的微波宽带频率合成器

为改善宽带频率合成器的相位噪声,提出一种基于Phase-Refining技术的微波宽带频率合成器结构与一种对其相位噪声的准确分析方法。首先,根据线性传递函数与叠加原理得到该频率合成器的相位噪声解析模型,通过对振荡器实测相位噪声谱型进行曲线拟合并带入模型中来准确预测其相位噪声性能。分析表明,在级联偏置锁相环中,整个输出频率范围内都可通过将反馈分频比最小化来改善其环路带宽内的相位噪声。实验结果表明,该频率合成器的输出频率范围为2.1~5.6 GHz,频率步进为1 Hz,当输出为2.1 GHz与5.6 GHz时,在频偏10 kHz处的相位噪声分别为-114.7 dBc/Hz与-108.2 dBc/Hz,其相位噪声测试结果与分析计算结果相吻合。     

A Q-band low phase noise monolithic AlGaN/GaN HEMT VCO

A Q-band 40-GHz GaN monolithic microwave integrated circuit voltage controlled oscillator (VCO) based on AlGaN/GaN high electron mobility transistor technology has been demonstrated. The GaN VCO delivered an output power of +25dBm with phase noise of -92dBc/Hz at 100-KHz offset, and -120dBc/Hz at 1-MHz offset. To the best of our knowledge, this represents the state-of-the-art for GaN VCOs in terms of frequency, output power, and phase noise performance. This work demonstrates the potential for the use of GaN technology for high frequency, high power, and low phase noise frequency sources for military and commercial applications.     

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.