Oscillators – Solid state active element oscillator – Transistors
Reexamination Certificate
2001-09-28
2003-10-07
Cunningham, Terry D. (Department: 2816)
Oscillators
Solid state active element oscillator
Transistors
Reexamination Certificate
active
06630871
ABSTRACT:
BACKGROUND
1. Field of the Invention
The present invention generally relates to micro-electromechanical (MEM) structures, and in particular, to MEM resonators.
2. Description of the Related Art
Communication systems generally require partitioning of the electromagnetic frequency spectrum. Communication transceiver devices therefore must be capable of high frequency selectivity, i.e., capable of selecting a given frequency band while rejecting all others. Frequency-selective devices, such as filters, oscillators and mixers are therefore some of the most important components within a transceiver and the quality of the devices generally dictates the overall architecture of a given transceiver.
In wireless communication devices (e.g., radio frequency (RF) devices and cellular communication devices), resonators are typically used for signal filtering and generation purposes. Currently, discrete crystals are often used to make the resonators. Such off-chip resonators are typically implemented at the board level and therefore impede the ultimate miniaturization of portable transceivers.
To miniaturize portable transceivers, micro-electromechanical (MEM) resonators have been contemplated, for example, for use in bandpass filters and reference oscillators. However, the existing MEM resonators may not provide adequate resonance frequencies high enough for wireless communication applications.
REFERENCES:
patent: 5914553 (1999-06-01), Adams et al.
patent: 5976994 (1999-11-01), Nguyen et al.
patent: 6278337 (2001-08-01), Chan et al.
patent: 6391675 (2002-05-01), Ehmke et al.
patent: 6424074 (2002-07-01), Nguyen
patent: 2002/0074897 (2002-06-01), Ma et al.
patent: 2002/0096967 (2002-07-01), Ma et al.
patent: WO 00/71981 (2000-11-01), None
patent: WO 01/61846 (2001-08-01), None
U.S. patent application Ser. No. 09/894,334, Ma et al., filed Jun. 27, 2001.
Nguyen, Clark T.-C., “High-Q Micromechanical Oscillators and Filters for Communications”, 1977 IEEE Int'l Symposium on Circuits and Systems, Jun. 9-12, 1997 Hong Kong, pp. 2825-2828.
PCT International Search Report mailed Apr. 4, 2003 regarding co-pending PCT application No. PCT/US 02/31157 filed Sep. 27, 2002.
Cheng Peng
Ma Qing
Blakely , Sokoloff, Taylor & Zafman LLP
Cunningham Terry D.
Intel Corporation
Tra Quan
LandOfFree
Center-mass-reduced microbridge structures for ultra-high... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Center-mass-reduced microbridge structures for ultra-high..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Center-mass-reduced microbridge structures for ultra-high... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3142107