A Ku band InGaP/GaAs HBT MMIC VCO with a balanced and a differential topologies

Two fully integrated voltage controlled oscillators (VCO) with low phase noise are presented. The VCOs are realized on a commercially available InGaP/GaAs heterojunction bipolar transistor (HBT) technology with an f/sub T/ of 30 GHz. The circuits are based on the balanced common base Colpitts topology and the capacitively coupled differential topology. To improve the quality factor of the LC tank, a 70-ohm microstrip line is incorporated as an inductor with a varactor. The balanced VCO provides single ended output power of 0 dBm and a phase noise of -90.5 dBc/Hz at 100 kHz offset from a carrier frequency 13.5 GHz. The differential VCO has single ended output power of -1.5 dBm and -88 dBc/Hz at 100 kHz offset from a carrier frequency of 12.2 GHz. The balanced and the differential VCOs achieve very low FOMs of -180.7 and -177.6 dBc/Hz, respectively.

[1]  C. Hedenas,et al.  Low phase noise, low power IC VCOs for 5-8 GHz wireless applications , 2000, IMS 2000.

[2]  Eduardo Artal,et al.  Low-noise monolithic Ku-band VCO using pseudomorphic HEMT technology , 1997 .

[3]  Songcheol Hong,et al.  An Isothermal Gummel-Poon Model Parameter Extraction of HBT for Self Heating Effects Using Pulsed Measurements , 2001 .

[4]  C. Plett,et al.  The effect of varactor nonlinearity on the phase noise of completely integrated VCOs , 2000, IEEE Journal of Solid-State Circuits.

[5]  D. Marchesan,et al.  A family of monolithic inductor-varactor SiGe-HBT VCOs for 20 GHz to 30 GHz LMDS and fiber-optic receiver applications , 2000, 2000 IEEE Radio Frequency Integrated Circuits (RFIC) Symposium Digest of Papers (Cat. No.00CH37096).

[6]  B.-U. H. Klepser,et al.  A 10 GHz SiGe BiCMOS phase-locked-loop frequency synthesizer , 2001, Proceedings of the IEEE 2001 Custom Integrated Circuits Conference (Cat. No.01CH37169).

[7]  C. Hedenas,et al.  Low phase noise, low power IC VCOs for 5-8 GHz wireless applications , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).

[8]  A. Hajimiri,et al.  Design issues in CMOS differential LC oscillators , 1999, IEEE J. Solid State Circuits.