Telecommunications – Receiver or analog modulated signal frequency converter – Noise or interference elimination
Reexamination Certificate
2005-07-25
2008-03-04
Le, Thanh Cong (Department: 2618)
Telecommunications
Receiver or analog modulated signal frequency converter
Noise or interference elimination
C455S339000, C327S552000
Reexamination Certificate
active
07340237
ABSTRACT:
The present invention discloses a dual-band active filter having filtering response and positive pass-band gain. The dual-band active filter includes an input match unit for gain match of the dual-band active filter and for having a band-pass filtering response; a first gain stage electrically connected to the first input match unit for providing the flat gain of the dual-band active filter; an inter-stage unit electrically connected to the first gain stage for matching gain and for having a band-stop filter response; a second gain stage electrically connected to the inter stage unit for providing the flat gain of the dual-band active filter; and an output unit electrically connected to the second gain stage for matching the dual-band active filter and for having a low-pass filtering response. The dual-band active filter according to the present invention uses the cascade connection of multiple filter stages to have band-pass filtering response at two different frequency bands and obtain high stop-band attenuation by providing plural transmission zeros in the stop-band.
REFERENCES:
patent: 5995814 (1999-11-01), Yeh
patent: 7245186 (2007-07-01), Chang et al.
patent: 2005/0186935 (2005-08-01), Kawama et al.
Article entitled “An Original Topology of Dual-Band Filter with Transmission Zeros” by C. Quendo et al., 2003 IEEE MTT-S Digest, pp. 1093-1096.
Article entitled “Dual-Band Step-Impedance Bandpass Filter For Multimode Wireless LANs” by Sheng-Fuh Chang et al., published in Electronics Letters, Jan. 8, 2004, vol. 40, No. 1.
Albert Chen
Hung-Cheng Chen
Sheng-Fuh Chang
Shu-Fen Tang
Wen-Lin Chen
Cong Le Thanh
Integrated System Solution Corp.
Pillsbury Winthrop Shaw & Pittman LLP
Sheng-Fuh Chang
LandOfFree
Dual-band active filter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dual-band active filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dual-band active filter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3961375