A low phase noise, small power dissipation and small sized K-band cascode differential voltage-controlled oscillator (VCO) with capacitive feedback topology using 0.18 μm CMOS technology is described. The VCO operated can be tuned between 19.1 GHz and 20.9 GHz and has low phase noise of -108.67 dBc/Hz at a 1 MHz offset. The output power of the 20.7 GHz is about -21.12 dBm. The Figure of merit (...

In this paper, a 24 GHz transformer-coupled VCO is presented for a wide linear tuning range in the 0.13-μm CMOS process. The measured results of the proposed VCO show that the center frequency is 23.5 GHz with 7.4% frequency tuning range. The output frequency curve has wide linear tuning region (5.5%) at the middle of the curve. Also, the VCO exhibits good phase noise of −110.23 dBc/Hz at an of...

This paper presents a novel wide tuning range CMOS Voltage Controlled Oscillator (VCO). VCO uses an on-chip variable inductor as an additional variable element to extend the tuning range of VCO. The fabricated variable inductor achieves the variable range of 35%. The VCO was fabricated using 0.35 μm standard CMOS process, and can be tuned continuously from 2.13 GHz to 3.28 GHz (tuning range of ...

So far, oscillators have been designed to perform a specific task while the key parameters such as phase-noise and power consumption are set by the hardware design and not by the communication system in an adaptive way. As the communication channel is often subject to changes, the conditions under which the oscillator operates should be changed as well. Therefore, the concept of design for adap...

This paper proposes a novel wideband voltage-controlled oscillator (VCO) for multi-band transceivers. The proposed oscillator has a core VCO and a tuning-range extension circuit, which consists of an injection-locked frequency divider (ILFD) and flip flop dividers. The two-stage differential ILFD generates quadrature outputs and realizes two, three, four, and six of divide ratio with very wide ...

A wide-tuning range QVCO with a novel complimentary-coupling scheme is presented. Two NMOS-only VCOs are coupled via complimentary PMOS injection transistors. This shifts the injection current away from the zerocrossings of the output voltage, thereby reducing the sensitivity of the VCO to injection noise, which results in significant phasenoise improvement. Phase-shift is achieved without freq...

This paper describes 3-GHz and 7-GHz tunableinductance LC-tank voltage-controlled oscillators (VCOs) implemented in 0.18-μm CMOS technology. Unlike the traditional tuning method by a varactor, a tunable inductor is employed in the VCO by using a transformer to compensate for the energy loss. The VCO facilitates the tuning frequency and low noise of the output signals, together with a variable i...

A novel capacitor bank is proposed to implement a wide-band CMOS voltage-controlled oscillator(V CO) with linearized tuning characteristics. Taking advantage of the Ohms law, the tuning voltage is replaced by the product of the current and resistance, which provides one more freedom degree for tuning than the conventional V CO. This novel voltage equivalent capacitance array(V ECA) is clearly d...

A 1.25GHz monolithic CMOS PLL clock synthesis unit was designed for data communications. The monolithic PLL consists of a ring oscillator, divider, phase/frequency detector, charge pump and on-chip loop filter. The voltage controlled oscillator incorporates a quadrature output ring structure with sub-feedback loop embedded to speed up the circuit. The design accommodates process, supply voltage...

PLL Basics A phase-locked loop is a feedback system combining a voltage controlled oscillator and a phase comparator so connected that the oscillator frequency (or phase) accurately tracks that of an applied frequencyor phase-modulated signal. Phase-locked loops can be used, for example, to generate stable output frequency signals from a fixed low-frequency signal. The phase locked loop can be ...