A Triple-Tuned Ultra-Wideband VCO

• Published in: IEEE transactions on microwave theory and techniques 2008-02, Vol.56 (2), p.346-354
• Main Authors: Tsuru, M., Kawakami, K., Tajima, K., Miyamoto, K., Nakane, M., Itoh, K., Miyazaki, M., Isota, Y.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bandwidth; Broadband communication; Circuit optimization; Circuit properties; Circuits; Design. Technologies. Operation analysis. Testing; Devices; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Emittance; Equivalent circuits; Exact sciences and technology; flip-chip devices; Heterojunction bipolar transistors; Integrated circuits; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave devices; Microwave oscillators; Microwaves; Noise levels; Oscillations; Oscillators, resonators, synthetizers; radar applications; RLC circuits; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Simulation; Tunable circuits and devices; Ultra wideband technology; varactors; Voltage-controlled oscillators; voltage-controlled oscillators (VCOs); Wideband
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2007.913377

We have already proposed a triple-tuned voltage-controlled oscillator (VCO) for achieving an ultra-wideband characteristic. The triple-tuned VCO consists of an active device and three tuned circuits. The fabricated VCO has achieved the oscillation bandwidth of 5.6-16.8 GHz and the phase noise of -114.9 dBc/Hz +/-2.9 dB at 1-MHz offset from the carrier. In this paper, for the first time, the conditions that the VCO achieves the ultra-wideband characteristic are clarified by formulation and simulation. It is also clarified that a transistor of the larger emitter size is suitable for the wideband VCO. In addition, the performances of the proposed VCO are compared with other reported wideband VCOs. As a result, it is shown that the proposed VCO has achieved the lowest figure of merit in the C-Ku-band.