Wide Tuning Range VCO Research Articles

Low phase noise and wide tuning range VCO using switchable weakly coupled VCO-cores

Low phase noise and wide tuning range VCO using switchable weakly coupled VCO-cores

A 330-GHz Wide Tuning Range VCO Based on Common-Base Cross-Coupled Topology in SiGe BiCMOS Technology

A 330-GHz Wide Tuning Range VCO Based on Common-Base Cross-Coupled Topology in SiGe BiCMOS Technology

A Wide Tuning-Range CMOS VCO with a Tunable Active Inductor

This study describes a wide tuning-range VCO using tunable active inductor (TAI) topology and cross-coupled pair configuration for radio frequency operation. The TAI used two feedback loops to form a cascode circuit to obtain more degrees of freedom for inductance value. The TAI-VCO was fabricated using a 0.18 μm CMOS technology. The coarse frequency tuning is achieved by TAIs while the fine tuning is controlled by varactors. The fabricated circuit provides an output frequency range from 0.6 to 7.2 GHz (169%). The measured phase noise is from −110.38 to −86.01 dBc/Hz at a 1 MHz offset and output power is from −11.11 to −3.89 dBm within the entire frequency range under a 1.8 V power supply.

IC design of low power, wide tuning range VCO in 90 nm CMOS technology

A low power VCO with a wide tuning range and low phase noise has been designed and realized in a standard 90 nm CMOS technology. A newly proposed current-reuse cross-connected pair is utilized as a negative conductance generator to compensate the energy loss of the resonator. The supply current is reduced by half compared to that of the conventional LC-VCO. An improved inversion-mode MOSFET (IMOS) varactor is introduced to extend the capacitance tuning range from 32.8% to 66%. A detailed analysis of the proposed varactor is provided. The VCO achieves a tuning range of 27–32.5 GHz, exhibiting a frequency tuning range (FTR) of 18.4% and a phase noise of −101.38 dBc/Hz at 1 MHz offset from a 30 GHz carrier, and shows an excellent FOM of −185 dBc/Hz. With the voltage supply of 1.5 V, the core circuit of VCO draws only 2.1 mA DC current.

A wide-range VCO with an automatic frequency, amplitude and gain calibration loop

This paper presents a wide tuning range VCO with an automatic frequency, amplitude and gain calibration loop. To cover the wide tuning range, the automatic frequency calibration (AFC) loop is used. In addition, to provide the optimum Negative-Gm to the LC tank in a wide frequency range, the number of active Negative-Gm circuits is designed to be switched digitally based on the target frequency. Also, the VCO gain should be calibrated digitally to compensate for the gain variation. The VCO tuning range is 2.6 GHz, from 1.7 to 4.3 GHz, and the power consumption is 2---4 mA from a 1.8 V supply. The measured VCO phase noise is ?120 dBc/Hz at 1 MHz offset.

A Wide Band VCO with Automatic Frequency, Gain, and Two-Step Amplitude Calibration Loop for DTV Tuner Application

This paper presents a wide tuning range VCO with an automatic frequency, gain, and two-step amplitude calibration loop for Digital TV (DTV) tuner applications. To cover the wide tuning range, the fully digital automatic frequency calibration (AFC) loop is used. In addition to the AFC loop, a two-step negative-Gm tuning loop is proposed to provide the optimum negative-Gm to the LC tank in a wide frequency range with a fine resolution. In the coarse negative-Gm tuning loop, the number of active negative-Gm cells is selected digitally based on the target frequency. In the fine negative-Gm tuning loop, the negative-Gm is tuned finely with the bias voltage of the VCO. Also, the digital VCO gain calibration scheme is proposed to compensate for the gain variation in a wide tuning range. The VCO tuning range is 2.6GHz, from 1.7GHz to 4.3GHz, and the power consumption is 2mA to 4mA from a 1.8V supply. The measured VCO phase noise is -120dBc/Hz at 1MHz offset.

Coarse–fine, wideband distributed voltage controlled oscillator for wireless applications

A new distributed voltage controlled oscillator (DVCO) is presented. The proposed topology allows a very wide tuning range VCO and fine-coarse tuning. The design of a prototype DVCO is discussed and measurements are reported showing improved performance in terms of phase noise, tuning range and power consumption.