Browsing by Author "Hsu, MT"

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A systematic approach for low phase noise CMOS VCO design
(2003-08-01)
Kao, YH
;
Hsu, MT
;
Hsu, MC
;
Wu, PA
;
傳播研究所
The fully integrated LC voltage controlled oscillator by 0.35 mum CMOS technology is demonstrated. It has 2 GHz oscillation frequency, 23.58 mW power consumption under 3 V biased and 9.1% frequency tuning. The layout optimization method of inductor to increase quality factor and also to reduce phase noise is used. A general method is proposed which is capable of making an effective prediction of F, device excess noise number, and acquiring the phase noise of oscillators accurately. From this proposed method, the low phase noise by calculation is. attained. The phase noise of measured value which shows good match with calculating data is about -115.5dBc/Hz at off set frequency 600 kHz.
Extraction of noise source from noise parameters with RF CMOS devices
(2001)
Kao, YH
;
Hsu, MT
;
Hsu, YM
;
傳播研究所
;
Institute of Communication Studies
The noise source extraction with two-port network of RF COMS devices is presented. We descried the correlation property with three different models. The correlation of noise source with the Y model and H model show the inductive characteristics, and the ABCD (transmission matrix) shows the capacitive characteristic. All the noise parameters are measured from 0.6G-6.0GHz.
One-pass GPKS and IMS authentication procedure for UMTS
(2005-06-01)
Lin, YB
;
Chang, MF
;
Hsu, MT
;
Wu, LY
;
資訊工程學系
Universal Mobile Telecommunications System (UMTS) supports Internet protocol (IP) multimedia services through IP multimedia core network subsystem (IMS). Since the IMS information is delivered through the general packet radio service (GPRS) transport network, a UMTS mobile station (MS) must activate GPRS packet data protocol (PDP) context before it can register to the IMS network. In the Third-Generation Partnership Project (3GPP) specifications, authentication is performed at both the GPRS and the IMS networks before an MS can access the IMS services. We observe that many steps in this 3GPP "two-pass" authentication procedure are identical. Based on our observation, this paper proposes an one-pass authentication procedure that only needs to perform GPRS authentication. At the IMS level, authentication is implicitly performed in IMS registration. Our approach may save up to 50% of the IMS registration/authentication traffic, as compared with the 3GPP two-pass procedure. We formally prove that the one-pass procedure correctly authenticate the IMS users.
Theoretical analysis of low phase noise design of CMOS VCO
(2005-01-01)
Kao, YH
;
Hsu, MT
;
傳播研究所
;
Institute of Communication Studies
A theoretical analysis on low phase noise of voltage-controlled oscillators (VCOs) based on complementary cross-coupled LC VCO by 0.35-mum complementary metal oxide semiconductor technology is demonstrated. From the procedure of optimization steps, the excess noise factor of the amplifier coming from the active device has been determined. The proposed VCO operates at 2 GHz with phase noise of -116 dBc/Hz at offset frequency 600 kHz. The power consumption is 22.62 mW under 3 V bias with 9.1% frequency tuning. The achievement of low phase noise is also matched with prediction by formula in the frequency domain.