A novel defected ground structure to improve the output power of a VCO.

Authors :: Liu, H. W.
Sun, X. W.
Cheng, Z. Q.
Li, Z. F.
Source :: Microwave & Optical Technology Letters. 8/20/2003, Vol. 38 Issue 4, p279-281. 3p. 1 Color Photograph, 1 Black and White Photograph, 1 Diagram, 2 Graphs.
Publication Year :: 2003
Abstract: In this paper, a novel defected ground structure (DGS), connected in parallel to two periodic structures with different center frequencies of the stopband, is proposed for increasing the output power of a voltage-controlled oscillator (VCO) in microstrip circuits. To evaluate the effects of DGS on the output power, two GaAs field-effect transistor (FET) VCOs have been designed and fabricated. One of them has a 50Ω microstrip line with DGS at the output section, while the other has only a 50Ω straight line. Measured results show that DGS rejects the second harmonic at the output and yields improved output power by 1–5%. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 279–281, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11038 [ABSTRACT FROM AUTHOR]