A Novel Dual-Band Six-Phase Voltage-Control Oscillator.

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• RF Engineering

Background:

• Single-ended delay cells offer advantages like lower power consumption and smaller chip area compared to differential delay cells.
• Conventional ring-type VCOs with even-phase outputs cannot be implemented using single-ended delay cells, limiting their application in sensor circuits.
• Existing VCOs often struggle to meet the diverse frequency requirements of modern sensor systems.

Purpose of the Study:

• To present a novel dual-band six-phase ring-type voltage-controlled oscillator (VCO) that integrates the benefits of single-ended delay cells.
• To overcome the limitation of even-phase outputs in conventional single-ended delay cell VCOs.
• To enhance VCO performance, particularly jitter, through a proposed band-switching delay cell.

Main Methods:

• Development of a novel single-ended delay cell with integrated band-switching functionality.
• Implementation of a six-phase ring-type VCO architecture utilizing the proposed delay cell.
• Fabrication and testing of the VCO in a United Microelectronics Corporation 0.18 μm RF CMOS process.

Main Results:

• The proposed dual-band six-phase VCO operates effectively between 890–1080 MHz.
• Achieved peak-to-peak jitter of 35.5 ps and root mean square (RMS) jitter of 2.8 ps at 1 GHz.
• Demonstrated maximal power consumption of approximately 6.4 mW at 1.8 V supply, with a chip area of 0.195 × 0.208 mm².

Conclusions:

• The novel single-ended delay cell successfully enables a dual-band six-phase ring-type VCO, combining advantages of both single-ended and differential architectures.
• The proposed VCO design addresses the need for efficient, compact, and high-performance oscillators in sensor circuit systems.
• The band-switching capability of the delay cell contributes to improved jitter performance, making the VCO suitable for demanding applications.