Transmission-line stabilized monolithic oscillators

A novel technique for frequency stabilization and phase-noise reduction of monolithic oscillators is presented in this paper. It employs simple transmission-line resonators, which are many wavelengths long to increase the oscillator quality factor. Monolithic oscillators at 20 and 40 GHz are realized for the application of this technique. Phase noise reduction of more than 20 dB was achieved for both oscillators. The single-sideband phase noise obtained was -100 dBc/Hz at 100-kHz offset for the 20-GHz oscillator and -90 dBc/Hz at 1-MHz offset for the 40-GHz oscillator. The approach is implemented by using readily available transmission lines, which are open- or short-circuited at one end and connected to the monolithic-microwave integrated-circuit (MMIC) oscillator at the other end. Thus, it presents significant potential in the development of low-cost MMIC oscillators with enhanced noise performance     

Magnetostatic wave resonators and oscillators

The purpose of this paper is to describe the current status of magnetostatic wave tunable resonators operating between 2 and 12GHz and their applications to microwave oscillators, the wave propagating in a pure yttrium-iron-garnet epi-layer. The first section deals with magnetostatic surface wave (MSSW) resonators consisting of a pair of reflective grooved gratings and two microstrip-transducers set between the gratings. Results on insertion loss, off-resonance frequency rejection andQ value are presented. However MSSW cavities suffer several disadvantages such as the small saturation power level at low frequencies and the difficulty to temperature compensate MSSW devices. These problems are overcome with magnetostatic forward volume waves (MSFVW). Then the second section is devoted to MSFVW resonators. A peculiar folded geometry made of five grooved gratings and two microstrip-transducers has been designed to provide a sufficient out-of-band rejection. The experimental characteristics of these resonators are given. In the last section of this paper are reported the features of tunable oscillators implemented with MSSW and MSFVW resonators in a hybrid configuration. Results about tunability, output power,FM phase noise are reported. MSFVW resonator stabilized oscillators are very promising and magnetostatic wave resonators seem a challenge to YIG spheres.This work was supported by the Direction des Recherches, Etudes et Techniques (France).     

Planar oscillators for monolithic integration

Planar oscillators for monolithic millimeter-wave integrated circuits are considered, and a design based on a coplanar-waveguide resonator is described. Design data are obtained from simulation at 1 GHz. the resonator has a Q of 195 (50 when scaled to 100 GHz) and is mechanically tunable over a range of 12%. Combining this resonator with a Gunn diode, a model oscillator is obtained. Output is obtained quasi-optically through a transmitting antenna. Twenty one milliwatts of output at 4.5 GHz are obtained with high spectral purity. A 100 GHz monolithic planar oscillator based on this design should be possible.     

Eigenpolarization theory of monolithic nonplanar ring oscillators

Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in a applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed     

Balanced monolithic oscillators at K- and Ka-band

A technique for generating accurate antiphase signals is presented in this paper. Monolithic oscillators at 20 and 40 GHz are realized using this technique. These oscillators have dual outputs that are mutually locked in antiphase. The inherent amplitude and phase balances between the output signals are verified. This is achieved by direct measurement using injection-locking polar diagrams, as well as low-frequency measurements of the down-converted oscillator outputs. The operation of the balanced oscillator as a multidevice power-combining oscillator is also investigated. Improvements of phase noise reduction and frequency stabilization are demonstrated at the combined oscillator output. This new oscillator topology shows significant potential in balanced circuits like mixers, multipliers, and modulators where circuit performance relies on the precise generation of the balanced signals     

Performance of monolithic GaAs FET oscillators at J-band

Monolithic GaAs FET oscillators were demonstrated at J-band frequencies. Output power up to 160 mW with 23-percent efficiency at 12 GHz was achieved. With a discrete tuning varactor, a 300-µm gate-width FET monolithic oscillator was tuned from 16 to 20 GHz. The average output power was l0 mW.     

定制振荡器的比较

设计师可以为他们的应用选择三种不同类型的振荡器。各种类型均有其优势和局限，要视其应用决定最佳选择。     

Compact and broad-band millimeter-wave monolithic transformer balanced mixers

Three broad-band miniature monolithic transformer singly balanced diode mixers for operation in the microwave and millimeter-wave bands are reported in this paper. The coupled-line equivalent models are used to synthesize the initial design of these transformers up to 50 GHz. The first one is a broad-band spiral transformer mixer, and the second one is a 21-GHz Marchand-type transformer mixer. These two mixers with chip sizes around 0.29 mm/sup 2/ exhibit bandwidths of 105% and 54.5%, respectively. We also propose a 30-GHz single-coiled transformer mixer, which has comparable performance with the first two mixers and reduced chip size. The single-coiled transformer mixer achieves a bandwidth of 100% with the chip size smaller than 0.25mm/sup 2/. In order to save chip area, all these transformers provide broad-band matching to the diodes directly. To the authors' knowledge, these mixers achieve the widest bandwidths with the smallest chip sizes among all passive balanced mixers using monolithic-microwave integrated-circuit processes in dc-40-GHz frequency range.     

Switched resonators and their applications in a dual-band monolithic CMOS LC-tuned VCO

A switched resonator concept, which can be used to reduce the size of multiple-band RF systems and which allows better tradeoff between phase noise and power consumption, is demonstrated using a dual-band voltage-controlled oscillator (VCO) in a 0.18-/spl mu/m CMOS process. To maximize Q of the switched resonator when the switch is on, the mutual inductance between the inductors should be kept low and the switch transistor size should be optimized. The Q factor of switched resonators is /spl sim/30% lower than that of a standalone inductor. The dual-band VCO operates near 900 MHz and 1.8 GHz with phase noise of -125 and -123dBc/Hz at a 600-kHz offset and 16-mW power consumption. Compared to a single-band 1.8-GHz VCO, the dual-band VCO has almost the same phase noise and power consumption, while occupying /spl sim/37% smaller area.     

Investigation of the noise characteristics of oscillators based on composite acoustic resonators

It is shown that composite acoustic resonators are promising microwave frequency-control components. It is found that, for a detuning from a carrier frequency exceeding 1 kHz, the phase noise of an oscillator stabilized by a composite resonator is lower than that of oscillators with surface-acoustic-wave crystal resonators and with AT-cut crystal resonators.     

Large signal design of broadband monolithic microwave frequencydividers and phase-locked oscillators

This paper presents a design method for phaselocked devices such as frequency dividers or injection-locked oscillators. The method requires a full nonlinear analysis of the circuit. This analysis relies upon harmonic balance techniques and is suitable for monolithic circuits simulation. First, a modified formulation of the general harmonic balance equation is proposed which includes the presence of probes. These probes allow us to suppress the degenerated solution of the HB equation in autonomous cases. Moreover, a global stability analysis of phaselocked regimes is carried out. It provides invaluable information on the nonlinear behavior of the device. In particular, synchronization bandwidths as well as power ranges for which the circuit can be synchronized are obtained from the stability loci drawn in the parameter space. All these features have been used to design a broadband monolithic frequency divider, and the simulated and experimental results have been compared with very good accuracy. Therefore, the method proposed is a very useful tool for the design of potentially unstable circuits     

High-sensitivity capacitive sensing interfacing circuit for monolithic CMOS M/NEMS resonators

A simple and high-sensitivity 0.35 mum CMOS readout circuit for resonant M/NEMS with capacitive sensing is presented. The proposed readout scheme presents an equivalent transimpedance gain of 140 dB Omega (at 1 MHz) and an input referred noise of 29 nV/Hz^1/2. Detection of submicrometre-scale cantilever vibrations in the MHz range is demonstrated with a displacement resolution of 33 ffn/Hz^1/2.     

Using parallel resonators to create improved maximally flatquarter-wavelength transformer impedance-matching networks

This paper presents a general approach for designing maximally flat quarter-wave transformer impedance-matching networks (QWT-IMNs) used in conjunction with parallel resonators. The approach used finds a maximally flat form by setting lower order terms of the general form to zero. This general form is found using ABCD matrices. The resulting maximally flat form is identical to the form for quarter-wavelength-coupled filters. Using parallel resonators improves QWT-IMN designs in three ways. First, adding parallel resonators to a QWT-IMN improves the poor stopband rejection from which QWT-IMN's suffer. Second, for a given load-to-source mismatch, a QWT-IMN has a fixed response, i.e., a fixed total Q. By using more than one parallel resonator, numerous response realizations, i.e., values of total Q, can be achieved for a given load-to-source mismatch. Third, using parallel resonators requires one less quarter-wave transformer to achieve the same order of response     

Wideband LC balun transformer using coupled LC resonators embedded into organic substrate

In this paper, wideband LC balun using coupled LC resonator has been newly designed, simulated, and fabricated. The proposed balun has a novel scheme which consists of two pairs of coupled embedded LC resonators which share one resonator with each other. The coupled resonators are applied to provide a precise phase difference of 180° and an identical magnitude between two balanced ports and DC isolation characteristic with impedance transformation. Furthermore, proposed resonators have relatively small inductance values which can be easily embedded into the organic package substrate. In order to reduce the size of embedded capacitors, BTO composite high dielectric film was applied to increase their capacitance densities. The measured results of fabricated wideband balun exhibited an insertion loss of 1.8 dB, a return loss of 10 dB, a phase imbalance of 0.5°, and magnitude imbalance of 0.7 dB at frequency bandwidth of 700 MHz ranged from 1.8 to 2.5 GHz, respectively. They agreed well with the simulated ones. The fabricated balun has a relatively small volume of 2 mm×3.5 mm×0.66 mm (height).     

Experimental study and theoretical prediction of aging induced frequency shift of crystal resonators and oscillators

Frequency shift, due to quartz crystal resonator aging, has been identified as one of the most important quality control problems of quartz crystal products. The problem becomes more significant due to the device miniaturization and high precision standards for telecommunication applications. Since aging induced frequency shift occurs during a long time frame, it is necessary to predict the long-term behavior of the devices based on the short-term data obtained under an accelerated environment. One the other hand, frequency shift is associated with quite large random variation, and thus, a proper probabilistic theory should be used for analyzing test data and for developing a reliable prediction model. Accelerated testing was performed for various types of crystal resonators under elevated temperatures. The frequency shifts of the devices were measured at different testing periods. Markov chain model was used to characterize the frequency shift of the devices. The obtained short-term test results were used for calibrating the probabilistic transition matrix of Markov chain model. The model can then be used for predicting the long-term frequency shift. The time–temperature superposition principle in viscoelasticity was adopted to address the shift in time under different temperatures.     

The use of saw oscillators to suppress fm noise in local oscillators for on-board satellite applications

SAW oscillators can provide fundamental frequency operation to above 1·5 GHz, with stability and FM noise performance approaching that offered by bulk crystal oscillator technology. Their high fundamental frequency, small size and rugged construction gives SAW technology a unique capability at UHF and microwave frequencies. The low FM thermal noise floor associated with fundamental frequency operation can be combined with the stability and low close-to-carrier noise of multiplied bulk crystal oscillators by locking a high frequency SAW oscillator to a bulk crystal reference. SAW oscillator stability is compatible with conventional phase-locked-loop techniques and also with injection lock stabilization, and their own low close-to-carrier FM noise ensures that such locked sources exhibit minimum phase noise. Furthermore, locked oscillator phase noise is not significantly degraded when extreme operating conditions, such as those experienced in space applications, demand a reduced SAW device Q for reliable locking using either technique. Use of a PLL avoids any need for reference frequency multiplication, and provides additional design flexibility with respect to reference frequency selection and phase noise optimization. Injection locking offers design simplicity and uses fewer frequency control components, which can contribute additional noise in PLL sources.     

High-Q active resonators using amplifiers and their applications to low phase-noise free-running and voltage-controlled oscillators

This paper presents a new technique to design high-Q active resonators. The active resonators are then used in the design of low phase-noise oscillators. The proposed new technique uses an amplifier to generate a negative resistance, which compensates for the resonator losses and increases the Q factor. The active resonator using this technique shows a high loaded Q factor of 548.62 from measurement at the fixed 10-GHz resonant frequency. Considerations to design a voltage tunable active resonator is given and measurements show that the loaded Q factors exceed 500 with a 120-MHz tuning range. A low phase-noise free-running and voltage-controlled oscillator (VCO) were designed as an application of the proposed active resonators. The phase noise of the free-running oscillator using the active resonator is -114.36 dBc/Hz at 100-kHz offset, which is 14 dB lower than the phase noise of the passive resonator oscillator. In the case of a VCO using the active resonator, the phase-noise performance is below -110 dBc/Hz over the whole tuning range, which is lower 13 dB compared to the passive resonator VCO. The total dc power consumptions are approximately 500 mW.     

Dielectric resonators suitable for use in planar integratedcircuits at short millimeter wavelengths

Experimental results are presented of planar whispering-gallery-mode dielectric resonators. The three-dimensional field pattern obtained by using finite-element techniques as well as measured resonant frequencies and quality factors carried out in the Ka (26.5-40 GHz) and 90-100-GHz bands is presented. The application to millimeter-wave components is discussed     

A monolithic transformer coupled 5-W silicon power amplifier with59% PAE at 0.9 GHz

This paper presents the circuit design and application of a monolithically integrated silicon radio-frequency power amplifier for 0.8-1 GHz. The chip is fabricated in a 25-GHz-f_T silicon bipolar production technology (Siemens B6HF). A maximum output power of 5 W and maximum efficiency of 59% is achieved. The chip is operating from 2.5 to 4.5 V. The linear gain is 36 dB. The balanced two-stage circuit design is based fundamentally on three on-chip transformers. The driver stage and the output stage are connected in common-emitter configuration. The input signal can be applied balanced or single-ended if one input terminal is grounded. One transformer at the input acts as balun as well as input matching network. Two transformers acts as interstage matching network     

Analysis of bilateral coplanar waveguides printed on anisotropicsubstrates for use in monolithic MICs

The spectral-domain method is applied to the analysis of bilateral (double-sided) coplanar waveguides that are printed on electric and/or magnetic anisotropic substrates. A nondecoupling approach is used to solve the coupled differential equations for the transverse propagation constants inside the substrate. The dyadic admittance Green's function is derived for both open and shielded bilateral coplanar waveguides, taking into account the anisotropy of the material. Finally, numerical results, describing the propagation characteristics of these structures, are presented for both electric and magnetic wall symmetries