• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.11
• /
• pp.2451-2456
• /
• 2011

This paper is a study on the high power amplifier to fulfill standards of the MOPS. VDR's frequency band is 117.975~137MHz, and CSMA(Carrier Sense Multiple Access), D8PSK(Differential Eight Phase Shift Keyed), 25KHz's channel bandwidth use. It also stated in DO-281A MOPS output power, symbol constellation error, spurious emissions, adjacent channel power must be met. We designed and measured the performance. The 38dB of the IM3 satisfies the MOPS standard.

• ETRI Journal
• /
• v.31 no.4
• /
• pp.478-480
• /
• 2009

The design of a CMOS clamped-clamped beam resonator along with a full custom integrated differential amplifier, monolithically fabricated with a commercial 0.35 ${\mu}m$ CMOS technology, is presented. The implemented amplifier, which minimizes the negative effect of the parasitic capacitance, enhances the electrical MEMS characterization, obtaining a $48{\times}10^8$ resonant frequency-quality factor product ($Q{\times}f_{res}$) in air conditions, which is quite competitive in comparison with existing CMOS-MEMS resonators.

• ETRI Journal
• /
• v.29 no.4
• /
• pp.421-429
• /
• 2007

This paper presents a direct-conversion CMOS transceiver for fully digital DS-UWB systems. The transceiver includes all of the radio building blocks, such as a T/R switch, a low noise amplifier, an I/Q demodulator, a low pass filter, a variable gain amplifier as a receiver, the same receiver blocks as a transmitter including a phase-locked loop (PLL), and a voltage controlled oscillator (VCO). A single-ended-to-differential converter is implemented in the down-conversion mixer and a differential-to-single-ended converter is implemented in the driver amplifier stage. The chip is fabricated on a 9.0 $mm^2$ die using standard 0.18 ${\mu}m$ CMOS technology and a 64-pin MicroLead Frame package. Experimental results show the total current consumption is 143 mA including the PLL and VCO. The chip has a 3.5 dB receiver gain flatness at the 660 MHz bandwidth. These results indicate that the architecture and circuits are adaptable to the implementation of a wideband, low-power, and high-speed wireless personal area network.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.12
• /
• pp.90-95
• /
• 2014

This paper presents a VHF/UHF-band variable gain low noise amplifier for multi-standard mobile TV tuners. A proposed VHF-band variable gain amplifier is composed of a resistive shunt-feedback low noise amplifier to remove external matching components, a single-to-differential amplifier with input PMOS transcoductors to improve low frequency noise performance, a variable shunt-feedback resistor and an attenuator to control variable gain range. A proposed UHF-band variable gain amplifier consists of a narrowband low noise amplifier with capacitive tuning to improve noise performance and interference rejection performance, a single-to-differential with gm gain control and an attenuator to adjust gain control range. The proposed VHF-band and UHF-band variable gain amplifier were designed in a $0.18{\mu}m$ RF CMOS technology and draws 22 mA and 17 mA from a 1.8 V supply voltage, respectively. The designed VHF-band and UHF-band variable gain amplifier show a voltage gain of 27 dB and 27 dB, a noise figure of 1.6-1.7 dB and 1.3-1.7 dB, OIP3 of 13.5 dBm and 16 dBm, respectively.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.4 no.4
• /
• pp.2-12
• /
• 1967

A pair of insulated-gate metal-oxide-semiconductor field-effect transistor has been used to measure the direct current produced from the ionization chamber in the range of to A. An analisis of direct-current differential amplifier giving the expressions of the common-mode rejection ratio and the rralization of the constant-current generator to give very large effective source resistance has been presented. Voltage gain is 6.6, drift at the room temperature is 1.5mv per day. The common-mode rejection ratio is obtained maximum 84db. These facts give the feasibility of small direct-current measurements by utilizing this type transistors.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.19 no.1
• /
• pp.14-19
• /
• 1982

A differential amplifier has been designed and fabricated using aluminum-gate PMOS technology, Only enhaneement-mode MOSFET's are used in the circuit and the dimensions of transistors have been determined using simulation program MSINC. The fabricated integrated circuit with +15V and -l5V power supplies shows an open-loop DC voltage gain of 42 dB, a common mode rejection ratio (CMRR) of 50 dB, and a Power consumption of 20mW.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.4 no.3
• /
• pp.28-33
• /
• 1967

The analysis of differential amplifier is simplified by the extention of bisection theorem. In order to reduce the thermal and porwor drifts, a self compensating circuit is employed. The optimum conditions of the self compensating circuit are: the base-emitter voltage of one transistor should be equal to the other's base-emitter voltage for basic self compensating circuit, the tempereature coefficients of base-emitter voltage of one transistor equal to the others for thermal compensation. By regarding the thermal and power drifts the experiments were performed were performed and the numerical results were consistent with the measured values.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.479-482
• /
• 1993

A fully balanced differential amplifier can achieve high-gain wide-bandwidth characteristics. And also, Offset PSRR, CMRR and Noise performance of that are excellent, but these merits can be achieved only when the architecture holds fully balanced. Commonly, the fully balanced differential amplifier has a common mode feedback(CMFB) circuit in order to maintain the balance. This paper presents improved characteristics of the CMFB circuit and designs the wide-bandwidth CMOS Op-amp. The unity gain bandwidth of this Op-amp is 50MHz with the load capacitor 2pF, and the value of phase margin is $85^{\circ}$.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.667-670
• /
• 1998

Novel bipolar transresistance amplifier(TRA) for high-accuracy current-mode signal processing is described. The TRA consists of two current follower for the current inputs, a current summer for curent-differential, and a voltage follower for the voltage output. The simulation results show that the impedence of the current input and the voltage output is 0.5 $\Omega$ and the 3-dB cutoff frequency when used as a current to voltage converter extends beyond 40 MHz.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.1009-1010
• /
• 2008

This paper presents a real-time aging measurement and feasible compensation system for the prolonged lifetime of OLED panel. The proposed system is composed of four parts, a PC with a man-machine interface, a measurement block, an adaptive amplifier block, and a compensation block. We apply a tree algorithm for less complexity and convenience of measurement on the degree of aging. An adaptive multi-stage differential amplifier is also implemented to deal with a various range of input voltages at the same spot.