Introduction A key circuit used in modern communication systems is the voltage controlled oscillator (VCO). The VCO's output is an AC waveform whose frequency is dependent upon the input voltage. In today's wireless communication systems, a greater maximum frequency range is required by VCOs. With respect to the digital phones that use these circuits, low power consumption, small size and low f...

This note will review the process by which VCO (Voltage Controlled Oscillator) designers choose their oscillator’s topology and devices based on performance requirements, components types and DC power requirements. Basic oscillator design specifications often require a given output power into a specified load at the design frequency. The drive level and bias current set the fundamental output c...

A 2.4GHz frequency synthesizer is proposed as a part of a low cost RF front end for ISM band applications. The frequency synthesizer employed a new dual loop architecture to improve the settling time, while keeping a fine frequency resolution. With a settling time of 30µs, the frequency synthesizer is able to hop at 2k hop/s with less than 10% overhead. When utilized in a digital wireless syste...

This thesis report presents system specification, such as frequency and output power level, and selection topology of an oscillator circuit suitable for a CMOS Integrated Doppler radar application, in order to facilitate short range target detection within 5-15 m range, using a 0.35 μm CMOS process. With this selected CMOS process, the frequency band at 2.45 GHz or 5 GHz, with a maximum output ...

In this paper we present a study on the design optimization of voltage-controlled oscillators. The phase noise of LC-type oscillators is basically limited by the quality factor of inductors. It has been experimentally shown that higher-Q inductors can be achieved at higher frequencies while the oscillation frequency is limited by parasitic capacitances. In this paper, the minimum transistor siz...

An ultra-low-power K-band LC-VCO (voltage-controlled oscillator) with a wide tuning range is proposed in this paper. Based on the current-reuse topology, dynamic back-gate-biasing technique utilized to reduce power consumption and increase range. With technique, small dimension cross-coupled pairs are allowed, reducing parasitic capacitors consumption. Implemented SMIC 55 nm 1P7M CMOS process, ...

Modern consumer electronics are designed as Analog/Mixed-Signal Systems-onChip (AMS-SoCs). In an AMS-SoC, the analog and mixed-signal portions have not received systematic attention due to their complex nature and the fact that their optimization and simulation consume significant portions of the design cycle time. This paper presents a new approach to reduce the design cycle time by combining ...

This paper presents a temperature compensation voltage controlled oscillator (VCO) based on Cross-Coupled pair and Colpitts structures which is suitable for military fields. Also, two inductors have been used for increasing the negative conductance. By using this method, start-up condition has been improved. Two varactors and a simple capacitor bank are applied for covering a wide tunning range...