The Q-band low noise reference oscillator based on bipolar transistor designed for the pulse ESR spectrometer
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The construction of the low noise Q-band reference oscillator based on the voltage controlled bipolar GaAs transistor for the transmitter of pulse microwave (MW) bridge designed for the pulse electron spin resonance (ESR) spectrometer has been presented. The application of the reference MW oscillator, which consists of a quartz crystal oscillator, frequency synthesizer and a low-noise GaAs bipolar transistor, instead of klystron or Gunn oscillator, results in the improvement of the phase and frequency noise of the pulse ESR spectrometer, which makes it well suited for the dating and diagnostics of the biomaterials by pulse ESR methods.Keywords:
Klystron
Crystal oscillator
A 200MHz high frequency crystal oscillator is developed.The composition and principle of the crystal oscillator are introduced and detailed design is presented.Simulation and test results show that this oscillator not only possesses excellent phase noise,but also achieves the expected antivibration design requirements.
Crystal oscillator
Pierce oscillator
Crystal oven
Crystal (programming language)
RC oscillator
Injection locking
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100.450 MHz 5th overtone temperature compensated crystal oscillator is developed. The oscillator is made up of 450 kHz ceramic oscillator, 100 MHz 5th overtone crystal oscillator, mixer and crystal filter. The output frequency of ceramic oscillator is mixed with that of crystal oscillator, and then the sum frequency is got by crystal filter. In this way, the 100 MHz crystal oscillator is compensated directly by the 450 kHz ceramic oscillator. Experiment results show that at 0～70℃ the frequency-temperature stability achieve ±7×10 -7, and its phase noise is -119 dBc@1 kHz.
Crystal oscillator
Overtone
Pierce oscillator
Crystal (programming language)
Crystal oven
RC oscillator
Oscillator phase noise
dBc
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A new type of frequency-modulation receiving system is described in which a continuously operating local oscillator is frequency-modulated by the received signal. In an embodiment of the system which is described, the oscillator is locked in with the received signal at one fifth the intermediate frequency. With this 5:1 relationship between the intermediate frequency and the oscillator frequency, an equivalent reduction in the frequency variations of the local oscillator is obtained. Received signal-frequency variations of ±75 kilocycles are reproduced as ±15-kilocycle variations in the oscillator frequency. The frequency-modulated signal derived from the oscillator is applied to a discriminator which is designed for this reduced range of frequencies. The oscillator is designed to lock in only with frequency variations which occur within the desired-signal channel. The oscillator is, therefore, prevented from following the frequency variations of a signal on an adjacent channel. A substantial improvement in selectivity is thus obtained. The voltage required to lock in the oscillator with a weak signal is approximately one twentieth of the voltage applied to the discriminator. Since this voltage gain is obtained at a different and lower frequency than the intermediate frequency, the stability of the receiver from the standpoint of over-all feedback is materially improved. Other performance advantages and the factors affecting the operation of the sytem are discussed.
SIGNAL (programming language)
Discriminator
Frequency deviation
Frequency multiplier
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본 논문에서는 100㎓ 대역 우주전파 수신시스템의 국부발진시스템에 대한 설계연구를 다루었다. 이 시스템의 기본 발진기로는 온도변화에 따른 주파수 및 위상 안정도가 좋고, 컴퓨터 제어가 용이한 디지털 드라이버를 사용하는 YIG 발진기를 사용하였다. 전체 시스템은 YIG 발진기, 3체 배기, 고조파 믹서 및 triplexer 등의 부품을 사용하는 발진부와 정확하고 안정된 국부발진 주파수를 만들어 믹서로 인가될 수 있도록 하는 PLL 시스템으로 구분하여 설계되었다. 본 연구에서 설계된 국부발진 시스템은 PC를 사용해 자동 혹은 수동으로 국부발진 주파수를 lock 할 수 있도록 설계되었으므로 밀리미터파 대역의 단일 픽셀 수신기나 다중 픽셀 수신기에 활용될 수 있다. In this paper, we make a design study for a local oscillator system of the 100 ㎓ band cosmic radio receiving system. We use the YIG oscillator with digital driver which is the main oscillator. This oscillator has a good frequency and phase stability at some temperature variation, and the easy computer aided control characteristics. This total system designed to two subsystem, first is the oscillator system include YIG oscillator, tripler, harmonic mixer and triplexer etc., second is the PLL system to supply the precise and stable local oscillator frequency to mixer. The proposed local oscillator system in this paper can be used in a single or multi pixel receiver because this system can be lock the local oscillator frequency automatically using PC.
Digitally controlled oscillator
Lock (firearm)
RC oscillator
Pierce oscillator
Colpitts oscillator
Crystal oscillator
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The importance of maintaining constant the frequency of radio transmitters has been universally recognized and the investigation of methods of frequency stabilization was left as a pending question after the first meeting of the C.C.I.R. The quartz-control system with thermostatic temperature control of the quartz crystal should be utilized when the highest precision (of the order of 0.001 per cent) is required in the constancy of the transmitted frequency. However, the system necessitates a complicated and expensive installation and at the same time the frequency of transmitters is not so flexible. When the highest precision is not of primary importance the following methods devised by the writers may be applied with the advantages of simplicity and lower cost of installation. These methods, fully described in the present paper, may readily be applied to a master oscillator so as to give a frequency stability of the order of 0.01 per cent. (a) Constant-frequency oscillator. In an ordinary self-oscillator, the effect of the variation in supply voltages may be minimized by simple means. Two methods have been developed for the purpose: 1. Resistance-stabilized oscillator. 2. Phase-compensated oscillator. (b) Quartz-stabilized oscillator. A quartz crystal is introduced in the grid circuit of an oscillator in such a manner that it is very loosely coupled to the oscillator but still retains its stabilizing function. Power output of the oscillator can be obtained up to 100 watts or more and thus the number of stages of amplifiers to be used in a transmitter can be reduced.
Crystal oscillator
Pierce oscillator
Crystal oven
RC oscillator
Parametric oscillator
Colpitts oscillator
Digitally controlled oscillator
Frequency standard
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The cavity stabilized microwave fundamental oscillator shown in Fig. 1 is conveniently used in IF heterodyne repeater systems for the receiver local oscillator. The frequency stability of the transmitter local oscillator is nearly the same as the receiver local oscillator, and shift oscillator stability determines the overall frequency stability of the transmitter. Harmonics of the shift oscillator do not affect either local signal.
Superheterodyne receiver
Colpitts oscillator
Repeater (horology)
Injection locking
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A sub-1-V low-complexity crystal oscillator (XTO) is fabricated in 65-nm CMOS. The proposed crystal oscillator has lower power dissipation and better frequency accuracy performance than reported ones. The crystal oscillator is based on the conventional three-point Colpitts architecture. The oscillator core consists of a constant gm gain stage, a quartz crystal and two load capacitors, followed by a single-ended self-biased band-passed amplifier. Experimental results show that the presented XTO generates a 12-MHz reference clock, achieving the phase noise of -95 dBc/Hz at 100-Hz offset frequency and the frequency inaccuracy of 1.2 ppm. The proposed crystal oscillator has an active area of 0.01 mm 2 and the power dissipation is 32 μW from a 0.8-V supply.
Colpitts oscillator
Crystal oscillator
Pierce oscillator
Crystal oven
RC oscillator
dBc
Crystal (programming language)
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Crystal oscillator
Variable capacitor
Varicap
Colpitts oscillator
Crystal oven
Superheterodyne receiver
SIGNAL (programming language)
Pierce oscillator
Digitally controlled oscillator
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Recent research shows that stable frequency is required to improve efficiency in the high frequency range. A high frequency oscillator has been required for the development of radio communications, measurement equipment, etc. Generally, the crystal oscillator is excellent in short-term frequency stability, and is being applied to telecommunication equipment, information technology, etc. On the other hand, the quartz resonator, which was developed for high frequency range, is aimed at being used in systems for the next generation. The quartz resonator with the high frequency range requires a steady oscillator to oscillate in high frequency range. Therefore, it is very difficult to use a Colpitts-type crystal oscillator in the high frequency range. It requires more negative resistance on the crystal oscillator circuit. In this paper, we suggest a method to decrease Miller capacitance of the transistor used for the conventional Colpitts-type crystal oscillator. Next, we show a new Colpitts-type crystal oscillator, which can obtain a negative resistance value in a gigahertz frequency band. Analyzing the equivalent circuit clarifies the effects of the proposed circuit compared to the conventional Colpitts-type crystal oscillator
Colpitts oscillator
Pierce oscillator
Crystal oscillator
Crystal oven
Crystal (programming language)
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A simplified model of the transistor sustaining stage employed in common quartz-crystal oscillators is presented. Examination of the model, including associated noise sources, provides an explanation for general differences observed in the output-frequency spectra of several types of widely used self-limiting crystal oscillator circuits. A self-limiting quartz-crystal oscillator circuit configuration is described that has been specifically designed to exhibit simultaneously each of the three important circuit characteristics necessary for improved oscillator short-term frequency/phase stability: large value of oscillator resonator loaded Q, adequate suppression of 1/f flicker-of-phase type noise, and improvement in oscillator ultimate signal-to-noise ratio. Several models of the oscillator circuit have been constructed employing high quality third overtone 5-MHz AT- and BT-cut quartz resonators. Measurement of oscillator short-term frequency stability using conventional phase lock and sampling techniques confirm attainment of substantial improvement in oscillator short-term frequency stability when compared to conventional self-limiting oscillator circuits.
Crystal oscillator
Crystal oven
Pierce oscillator
Oscillator phase noise
Flicker noise
Overtone
Digitally controlled oscillator
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Citations (26)