Yong-Kuk Park

A Low Power Fully CMOS Integrated RF Transceiver IC for Wireless Sensor Networks

A fully CMOS integrated RF transceiver for ubiquitous sensor networks in sub-gigahertz industrial, scientific, and medical (ISM)-band applications is implemented and measured. The integrated circuit is fabricated in 0.18-mum CMOS technology and packaged in leadless plastic chip carrier (LPCC) package. The fully monolithic transceiver consists of a receiver, a transmitter, and an RF synthesizer with on-chip voltage-controlled oscillator. The chip fully complies with the IEEE 802.15.4 wireless personal area network in sub-gigahertz mode. The cascaded noise figure of the overall receiver is 9.5 dB and the overall transmitter achieves less than 6.3% error vector magnitude for 40 kb/s mode. The chip uses 1.8-V power supply and the power consumption is 25 mW for reception mode and 29 mW for transmission mode

System Design Considerations for a ZigBee RF Receiver with regard to Coexistence with Wireless Devices in the 2.4GHz ISM-band

At the present time the task of designing a highly integrated ZigBee radio frequency (RF) receiver with an excellent coexistence performance is still very demanding and challenging. This paper presents a number of system issues and design considerations for a ZigBee RF receiver, namely IEEE 802.15.4, for coexistence with wireless devices in the 2.4-GHz ISM-band. With regard to IEEE 802.15.4, the paper analyzes receiver performance requirements for; system noise figure (NF), system third-order intercept point (system-IIP3), local oscillator phase noise and selectivity. Based on some assumptions, the paper illustrates the relationship between minimum detectable signal (MDS) and various situations that involve the effects of electromagnetic interference generated by other wireless devices. We infer the necessity of much more stringent specification requirements than the published standard for various wireless communication field environments

Performance enhancement of DVB-RCT systems for interactive wireless broadcasting

Orthogonal frequency-division multiple access (OFDMA), which is a combination of orthogonal frequency division multiplexing (OFDM) with frequency-division multiple access (FDMA), is regarded as a promising solution for enhancing the performance of interactive broadcasting wireless systems. This paper presents our investigation for the impacts of symbol timing errors and peak-to-average power ratio (PAR) on OFDMA-based interactive broadcasting systems. Under the condition of the same side information bits, the selective mapping (SLM) approach can be implemented by decimating OFDM samples, which is less complex compared to the ordinary SLM incurring a slight degradation of the PAR performance. Including the effects of clipping operation and symbol timing misalignment, the bit error rate (BER) performance is investigated for a typical OFDMA uplink scenario.

A CMOS continuous-time Gm-C filter and programmable gain amplifier for WPAN receivers

This paper describes a low-voltage and low-power channel selection analog front end with continuous-time low pass filters and highly linear programmable-gain amplifier(PGA). The filters were realized as balanced Gm-C biquadratic filters to achieve low current consumption. High linearity and constant wide bandwidth are achieved by using a new transconductance(Gm) cell. The POA has a voltage gain varying from 0 to 65 dB, while maintaining a constant bandwidth. A filter tuning circuit that requires an accurate time base but no external components is presented. Both the filter and PGA were implemented in a 0.18um 1P6M n-well CMOS process. They consume 3.2 mW from a 1.8 V power supply and occupy an area of 0.19 mm2.

A Fully CMOS Integrated RF Transceiver for Ubiquitous Networks in Sub-GHz ISM-band

A fully CMOS integrated radio frequency (RF) transceiver for wireless sensor networks in sub-GHz ISM-band applications is implemented and measured. The IC is fabricated in 0.18-mum CMOS technology and packaged in LPCC package. The fully monolithic transceiver consists of a receiver, a transmitter and a RF synthesizer with on-chip VCO. The chip fully complies with the IEEE 802.15.4 WPAN standard in sub-GHz mode. The receiver sensitivity is -98 dBm and the transmitter achieves less than 6.3% error vector magnitude (EVM) for 40 kbps mode. The chip uses 1.8 V power supply and the current consumption is 14 mA for reception mode ad 16 mA for transmission mode

A Novel Modeling and Performance Analysis of Imperfect Quadrature Modulator in RF Transmitter

In a wireless communication RF transmitter, the output of a quadrature modulator (QM) is distorted by not only the linear imperfection features such as in/quadrature-phase (I/Q) input gain imbalance, local phase imbalance, and local gain imbalance but also the nonlinear imperfection features such as direct current (DC) offset and mixer nonlinearity related to in-band spurious signal. In this paper, we propose the unified QM model to analyze the combined effects of the linear and nonlinear imperfection features on the performance of the QM. The unified QM model consists of two identical nonlinear systems and modified I/Q inputs based on the two-port nonlinear mixer model. The unified QM model shows that the output signals can be expressed by mixer circuit parameters such as intercept point and gain as well as the imperfection features. The proposed approach is validated by not only simulation but also measurement.

A Single Sideband RF-Modulator for Digital-IF Transmitter

The limitation of the single-sideband rejection ratio (SSRR) performance of transmitters based on I/Q mismatching due to high frequency signals has been investigated. The proposed single-sideband radio frequency-modulator (SSM) is capable of generating a single sideband frequency without implementing a quadrature local oscillator which displaces a phase of a local oscillating signal by 90deg at a high frequency. This technique is promising for radio transmission with a SSRR of more than 60 dBc. Also, the architecture of digital-intermediate frequency transmitter using the proposed SSM can be applied for a future software-defined radio solution supporting multiband and multimode wireless communications.

Analysis of Power Amplifier Nonlinear Response Based on Practical Circuit Parameters

In this paper, a novel analysis on the nonlinear response of a power amplifier (PA) with the intermodulation distortion (IMD) asymmetry is proposed based on the mutislice behavioral model. The coefficients of the odd-order and even-order polynomial of that model are represented with the PA practical circuit parameters such as intercept points, gain and amplitudes of excitation inputs. We also develop the analytic expressions to distinguish baseband frequency effect from second harmonic effect on the IMD asymmetry. We also validate the derived analytic expressions through measurements.

A ully CMOS Integrated R Transceiver for biquitous Sensor etworks in Sub- z ISM-band

A fully CMOS integrated radio frequency (RF) transceiver for wireless sensor networks in sub-GHz ISM-band applications is implemented and measured. The IC is fabricated in 0.18-mum CMOS technology and packaged in LPCC package. The fully monolithic transceiver consists of a receiver, a transmitter and a RF synthesizer with on-chip VCO. The chip fully complies with the IEEE 802.15.4 WPAN standard in sub-GHz mode. The receiver sensitivity is -98dBm and the transmitter achieves less than 6.3% error vector magnitude (EVM) for 40kbps mode. The chip uses 1.8V power supply and the current consumption is 14mA for reception mode and 16mA for transmission mode

RF Receiver Specifications of Ubiquitous Network for Coexistence with Various Wireless Devices in 2.4GHz ISM-band

This paper describes the analysis for implementation of a radio frequency (RF) receiver for low-rate wireless personal area networks (LR-WPANs), namely IEEE 802.15.4, for coexistence with various wireless devices in 2.4 GHz ISM-band. With IEEE 802.15.4 standard specification, it provides analysis of receiver performance requirements containing the system noise figure (NF), system third-order intercept point (IIP3 ), local oscillator phase noise and selectivity. With some assumption, it illustrates the relationship between minimum detectable signal (MDS) and various situations considering for the effects of noise generated from other wireless devices according to communication distance. Here, we can infer the necessity of much tighter specification requirements than that of the standards for various communication field environments