Theoretical modeling and laboratory tests are conducted for nonlinear auto-oscillating piezoelectric ultrasonic devices coupled to reverberant elastic bodies. The devices are shown to exhibit behavior familiar from the theory of coupled auto-oscillators. In particular, these spontaneously emitting devices adjust their limit-cycle frequency to the spectrum of the body. It is further shown that t...

This paper describes the simulations performed in order to evaluate expected performance of the voltage-controlled oscillator (VCO) based on differential ring oscillator with SCFL delay cells in 0.5μm GaAs MESFET technology. The ring oscillator structures with buffer cells are also simulated. The frequency range and tuning sensitivity are extracted. Finally, jitter simulations are performed in ...

A MMIC colpitts oscillator in push-push configuration is presented using InGaP/GaAs HBTs. The output at the second harmonic enhances the frequency range while preserving the well-known advantages of the Colpitts concept. Moreover, additional features like enhanced load-pull immunity and inherent frequency divider functionality are included. The MMIC VCO reaches state-of-the-art phasenoise perfo...

The oscillators based on an active transmission line periodically loaded with RTD pairs are studied using circuit simulation with special attention to the behavior of harmonics. Generation of strong high order harmonic (9th) was observed. This is caused by the frequency locking in the high frequency passband. The harmonic oscillators based on this phenomenon are promising for high performance T...

A new electronically tunable current-mode sinusoidal oscillator with three quadrature outputs is presented. The proposed circuit employs three translinear conveyors and two grounded capacitors to realize three quadrature outputs with independent frequency control. The circuit requires no resistors and the frequency of the oscillator can be varied over a wide range by external current control. R...

A 1.2V 5GHz low-cost voltage-controlled oscillator (VCO) with active common mode feedback has been implemented in a CMOS/RF 90nm technology for a robust I/Q generation using a frequency divider-by-2 (DIV2). As the input common mode of the DIV2 affects critically its performance, a calibration method to correct the output common mode of the VCO has been proposed and validated through post-layout...

The recent rapid growth in demand for wireless communications has been a strong motivation for designing more highly integrated RF ICs like low-noise amplifiers (LNAs), upand down-frequency converters, voltagecontrolled oscillators (VCOs), and frequency synthesizers into a single die with low power consumption and cost, while meeting performance requirements for wireless communications systems....

We describe and demonstrate a new oscillator topology, the parametric feedback oscillator (PFO). The PFO paradigm is applicable to a wide variety of nanoscale devices and opens the possibility of new classes of oscillators employing innovative frequency-determining elements, such as nanoelectromechanical systems (NEMS), facilitating integration with circuitry and system-size reduction. We show ...

if , then , where is the constant oscillator amplitude, set (arbitrarily) by initial conditions. An automatic amplitude control loop can be used to adjust exactly at ‘0’ and make the final oscillator amplitude be set at a specified reference voltage . Fig. 1 illustrates this. It is known that, if stays sufficiently close to zero so that the oscillator frequency can be considered constant, then ...

In this paper, a new differential delay cell is proposed and 16-bit Digital Controlled Oscillator (DCO) based on proposed delay cell is designed. The 16-bit DCO consist of 4-stages differential delay cell in ring structure and a digital control scheme has been used to improved noise characteristics. The structure of the DCO utilizes dual delay path techniques to achieve high oscillation frequen...