Patents by Inventor Donhee Ham

Donhee Ham has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050068127
    Abstract: Methods and apparatus involving semiconductor devices based on coplanar striplines (CPS). In one example, high-speed microelectronic devices based on coplanar stripline implementations support differential signals in a range of approximately from 1 Gigahertz to at least 60 Gigahertz. In one aspect, CPS-based devices incorporate various features that dramatically increase the quality factor Q of the resulting device. In another aspect, an enhancement of the quality factor Q is achieved while at the same time reducing the phase velocity of one or more waves propagating in the device, thereby also facilitating the fabrication of relatively smaller devices. In yet another aspect, a tapered coplanar stripline configuration results in position-dependent line parameters, which may be exploited to achieve significantly high-Q devices.
    Type: Application
    Filed: July 19, 2004
    Publication date: March 31, 2005
    Applicant: President and Fellows of Harvard College
    Inventors: Donhee Ham, William Andress, Yong Liu
  • Publication number: 20050068116
    Abstract: Methods and apparatus for implementing standing wave oscillators (SWOS) using coplanar striplines (CPS). One example is given by a quarter-wavelength (?/4) coplanar stripline standing wave oscillator (SWO), while another implementation utilizes a closed-loop coplanar stripline configuration. In various aspects, SWOs are configured to optimize sinusoidal performance at high frequencies with low power dissipation by incorporating various features that dramatically increase the quality factor Q of the oscillator. In particular, in one aspect, an amplitude-dependent tailored distributed amplification scheme is employed as a mode control technique using multiple amplifiers having different gains along the length of the coplanar stripline. In another aspect, a coplanar stripline configured such that its resistance per unit length R and conductance per unit length G are discreet or continuous functions of position along the coplanar stripline is employed to reduce SWO losses.
    Type: Application
    Filed: July 19, 2004
    Publication date: March 31, 2005
    Applicant: President and Fellows of Harvard College
    Inventors: Donhee Ham, William Andress, Yong Liu