Browsing by Author "Tsai"

Now showing 1 - 5 of 5

Charge pump circuit suitable for low-voltage process
(2006-12-05)
Ker
;
Ming-Dou
;
Tsai
;
Chia-Sheng
The present invention discloses a charge pump circuit suitable for a low-voltage process. The charge pump circuit is composed of stages of the voltage amplifying circuits connected each other, and the operation of two adjacent stages of voltage amplifying circuit is controlled by two opposite set of the timing signals. Each stage of the voltage amplifying circuit has a coupled pair of a first complementary MOS (CMOS) transistor and a second CMOS transistor switching in accordance with a timing signal and an inverse timing signal inputted into the first and second capacitors. Then, two diode devices guide charges to next stage, and a voltage higher than the integrated circuit voltage source is outputted. The present invention has advantage of high pumping gain, and the reliability issue of the gate oxide layer in the low-voltage process can be also solved.
Fabrication of true apodized fiber Bragg grating using a new two-beam interferometer with polarization control
(2005-11-08)
Chuang
;
Kai-Ping
;
Sheu
;
Lih-Gen
;
Tsai
The present invention provides a two-beam interference exposure system that can be simply adjusted by rotating only one mirror. By placing a half-wave plate in one of the interference arms and precisely scanning the relative fiber position, the present invention can expose true apodized fiber Bragg gratings in a single scan by simultaneously rotating the angle of the half-wave plate. By rotationally switching the fast and slow axes of the half-wave plate, the present invention can also expose n-phase-shifted fiber grating by the same system.
Fiber-optic tunable filter and intensity modulater
(2006-04-04)
Chen
;
Nan-Kuang
;
Chi
;
Sien
;
Tseng
A fiber-optic tunable filter and an intensity modulator respectively includes: a fiber having a polished surface and an evanescent-field; and a photonic crystal having plural cavities and a filler filled therein and attached to the polished surface, wherein the plural cavities and the filler decide a photonic band-gap of the photonic crystal and the photonic band-gap is adjusted to reflect a light with a specific wavelength through the evanescent interaction with the photonic crystal material. Based on the fiber side-polishing technique, all kinds of fiber active and passive devices are able to be manufactured easily, especially for a high speed intensity modulator using an EO (Electro-Optic) polymer as the filler.
Heterogeneity-projection hard-decision interpolation method for color reproduction
(2009-10-27)
Tsai
;
Chi-Yi
;
Song
;
Kai-Tai
The present invention discloses a heterogeneity-projection hard-decision interpolation method for color reproduction, which utilizes a heterogeneity-projection method to determine the optimal edge direction and then utilizes a hard-decision rule to determine the optimal interpolation direction and obtain the information of the green color elements. The high-frequency information of the plane of the green color elements is incorporated into the processing of the planes of the red color elements and the blue color elements to reduce the restoration errors of the red and blue color elements. Therefore, the present invention can decrease the interpolation-direction errors and achieve a higher PSNR and a better visual effect.
Multi-slope handoff algorithm for controlling dynamic communication quality in wireless communications
(2007-07-10)
Huang
;
Ching Yao
;
Tsai
;
Ming Yuan
;
Huang
A multi-slope handoff algorithm for controlling dynamic communication quality in wireless communications is proposed to let a mobile node adjust the handoff slope according to different communication connection situations for setting the optimum add/drop connection trigger thresholds. The algorithm comprises the following steps. First, a mobile node receives pilot strengths of its service pilot and nearby pilots to produce an aggregate strength. Next, the mobile node determines whether to perform handoff according to the magnitude of the aggregate strength. The handoff action is then controlled by multi-slope handoff operations to set an appropriate slope and to calculate the add/drop connection trigger thresholds when performing handoff. Finally, the pilot to be connected is selected based on the communication quality at that time. In this way, the quality of the communication service can be enhanced, the connection power consumption can be lowered, and the communication channel usage can be reduced.