2.6 A 190.5GHz mode-switching VCO with 20.7% continuous tuning range and maximum power of −2.1dBm in 0.13µm BiCMOS

Wideband mm-Wave and terahertz (THz) applications, including high data-rate communications, high-resolution radar and spectroscopy, require wideband signal sources. Nevertheless, low quality factor of varactors and lossy switches in addition to relatively large parasitic capacitors of transistors have been limiting the tuning range of voltage controlled oscillators (VCO) at these frequencies. To overcome these challenges, harmonic VCOs using high harmonic numbers and switched-capacitor banks at much lower fundamental frequencies were reported [1]. The drawback to this approach is the limited output power since the extracted harmonic number is typically high. Other tuning techniques such as phase/delay control between coupled oscillators and tuning boosting using transformer-based resonators were also reported [2-4]. However, the highest reported tuning range for VCOs above 150GHz is not more than 12.5%, which covers a small portion of the bandwidth available at high mm-Wave and THz frequencies.

[1]  Ehsan Afshari,et al.  14.8 A 247-to-263.5GHz VCO with 2.6mW peak output power and 1.14% DC-to-RF efficiency in 65nm Bulk CMOS , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[2]  Zheng Wang,et al.  A Silicon-Based 0.3 THz Frequency Synthesizer With Wide Locking Range , 2014, IEEE Journal of Solid-State Circuits.

[3]  Ehsan Afshari,et al.  High Power Terahertz and Millimeter-Wave Oscillator Design: A Systematic Approach , 2011, IEEE Journal of Solid-State Circuits.

[4]  Ehsan Afshari,et al.  A 260GHz broadband source with 1.1mW continuous-wave radiated power and EIRP of 15.7dBm in 65nm CMOS , 2013, 2013 IEEE International Solid-State Circuits Conference Digest of Technical Papers.

[5]  Songcheol Hong,et al.  Design and Analysis of 239 GHz CMOS Push-Push Transformer-Based VCO With High Efficiency and Wide Tuning Range , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[6]  Jing Zhang,et al.  85-to-127 GHz CMOS Signal Generation Using a Quadrature VCO With Passive Coupling and Broadband Harmonic Combining for Rotational Spectroscopy , 2015, IEEE Journal of Solid-State Circuits.

[7]  Ehsan Afshari,et al.  A 283-to-296GHz VCO with 0.76mW peak output power in 65nm CMOS , 2012, 2012 IEEE International Solid-State Circuits Conference.