45 research outputs found
A 0.8 V T Network-Based 2.6 GHz Downconverter RFIC
A 2.6 GHz downconverter RFIC is designed and implemented using a 0.18 μm CMOS standard process. An important goal of the design is to achieve the high linearity that is required in WiMAX systems with a low supply voltage. A passive T phase-shift network is used as an RF input stage in a Gilbert cell to reduce supply voltage. A single supply voltage of 0.8 V is used with a power consumption of 5.87 mW. The T network-based downconverter achieves a conversion gain (CG) of 5 dB, a single-sideband noise figure (NF) of 16.16 dB, an RF-to-IF isolation of greater than 20 dB, and an input-referred third-order intercept point (IIP3) of 1 dBm when the LO power of -13 dBm is applied
High Dynamic Range RF Front End with Noise Cancellation and Linearization for WiMAX Receivers
This research deals with verification of the high dynamic range for a heterodyne radio frequency (RF) front end. A 2.6 GHz RF front end is designed and implemented in a hybrid microwave integrated circuit (HMIC) for worldwide interoperability for microwave access (WiMAX) receivers. The heterodyne RF front end consists of a low-noise amplifier (LNA) with noise cancellation, an RF bandpass filter (BPF), a downconverter with linearization, and an intermediate frequency (IF) BPF. A noise canceling technique used in the low-noise amplifier eliminates a thermal noise and then reduces the noise figure (NF) of the RF front end by 0.9 dB. Use of a downconverter with diode linearizer also compensates for gain compression, which increases the input-referred third-order intercept point (IIP3) of the RF front end by 4.3 dB. The proposed method substantially increases the spurious-free dynamic range (DRf) of the RF front end by 3.5 dB
Compensating for the Threshold Voltages of Both the Driving Thin-Film Transistor and the Organic Light-Emitting Diode for Active-Matrix Organic Light-Emitting Diode Displays
This paper proposes a novel pixel circuit design and driving method for active-matrix organic light-emitting diode (AM-OLED) displays that use low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) as driving element. The automatic integrated circuit modeling simulation program with integrated circuit emphasis (AIM-SPICE) simulator was used to verify that the proposed pixel circuit, which comprises five transistors and one capacitor, can supply uniform output current. The voltage programming method of the proposed pixel circuit comprises three periods: reset, compensation with data input, and emission periods. The simulated results reflected excellent performance. For instance, when Δ TH = ±0.33 V, the average error rate of the OLED current variation was low (< 0.8%), and when Δ TH OLED = +0.33 V, the error rate of the OLED current variation was 4.7%. Moreover, when the × (current × resistance) drop voltage of a power line was 0.3 V, the error rate of the OLED current variation was 5.8%. The simulated results indicated that the proposed pixel circuit exhibits high immunity to the threshold voltage deviation of both the driving poly-Si TFTs and OLEDs, and simultaneously compensates for the × drop voltage of a power line
DIMENSION REDUCTION FOR POWER SYSTEM MODELING USING PCA METHODS CONSIDERING INCOMPLETE DATA READINGS
Principal Component Analysis (PCA) is a popular method for dimension reduction that can be used in many fields including data compression, image processing, exploratory data analysis, etc. However, traditional PCA method has several drawbacks, since the traditional PCA method is not efficient for dealing with high dimensional data and cannot be effectively applied to compute accurate enough principal components when handling relatively large portion of missing data. In this report, we propose to use EM-PCA method for dimension reduction of power system measurement with missing data, and provide a comparative study of traditional PCA and EM-PCA methods. Our extensive experimental results show that EM-PCA method is more effective and more accurate for dimension reduction of power system measurement data than traditional PCA method when dealing with large portion of missing data set
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Existence and uniqueness of solution for multidimensional parabolic PDAEs arising in semiconductor modeling
This paper concerns with a compact network model combined with distributed models for semiconductor devices. For linear RLC networks containing distributed semiconductor devices, we construct a mathematical model that joins the differential-algebraic initial value problem for the electric circuit with multi-dimensional parabolic-elliptic boundary value problems for the devices. We prove an existence and uniqueness result, and the asymptotic behavior of this mixed initial boundary value problem of partial differential-algebraic equations
Electromagnetic Compatibility Research in Wire Harnesses and CAN Transceivers
This dissertation develops methods how to design wire harnesses reducing common mode components and to analyze the conversion from differential mode to common mode. The three chapters presented are design methods how to figure out the impact of the common-mode components, not only describe the test results but provide important insight as to how the design related to radiated emissions. In the first chapter of this dissertation, the method designing wire harnesses has been presented to match the electrical balance of the circuit board (PCB). This is accomplished via calculating the current division factor (CDF) of the wire harnesses and the PCB, which provides us with the electrical balance of a transmission line. To reduce the amount of common-mode currents induced on the harness, matching the imbalance of the wire harness to the imbalance of its source and termination is essential. The second chapter explores Controller Area Network (CAN) characteristics. Unintentional common-mode components of the CAN transceivers are analyzed and evaluated to determine how much common-mode voltage they produce in various circumstances. The final chapter provide valuable understanding such that ground proximity impacts on the common-mode currents of wire harnesses. The electrical balance change of the wire harness depending on the distance from ground structures is highlighted. It is also analyzed that losing the ground wire impacts on the common-mode excitation