Joonho Gil

A simple wide-band on-chip inductor model for silicon-based RF ICs

In this paper, we developed a simple wide-band inductor model that contains lateral substrate resistance and capacitance to model the decrease in the series resistance at high frequencies related to lateral coupling through the silicon substrate. The model accurately predicts the equivalent series resistance and inductance over a wide-frequency range. Since it has frequency-independent elements, the proposed model can be easily integrated in SPICE-compatible simulators. The proposed model has been verified with measured results of inductors fabricated in a 0.18-/spl mu/m six-metal CMOS process. We also demonstrate the validity of the proposed model for shielded inductors. The proposed model shows excellent agreement with measured data over the whole frequency range.

The impact of semiconductor technology scaling on CMOS RF and digital circuits for wireless application

The impact of CMOS technology scaling on the various radio frequency (RF) circuit components such as active, passive and digital circuits is presented. Firstly, the impact of technology scaling on the noise and linearity of the low-noise amplifier (LNA) is thoroughly analyzed. Then two new circuits, i.e., CMOS complementary parallel push-pull (CCPP) circuit and vertical-NPN (V-NPN) circuit for direct-conversion receiver (DCR), are introduced. In CCPP, the high RF performance of pMOS comparable to nMOS provides single ended differential RF signal processing capability without the use of a bulky balun. The use of parasitic V-NPN bipolar transistor, available in triple well CMOS technology, has shown to provide more than an order of magnitude improvement in 1/f noise and dc offset related problems, which have been the bottleneck for CMOS single chip integration. Then CMOS technology scaling for various passive device performances such as the inductor, varactor, MIM capacitor, and switched capacitor, is discussed. Both the forward scaling of the active devices and the inverse scaling of interconnection layer, i.e., more interconnection layers with effectively thicker total dielectric and metal layers, provide very favorable scenario for all passive devices. Finally, the impact of CMOS scaling on the various digital circuits is introduced, taking the digital modem blocks, the various digital calibration circuits, the switching RF power amplifier, and eventually the software defined radio, as examples.

A simple parameter extraction method of spiral on-chip inductors

Accurate measurement and parameter extraction for spiral inductors are very important in monolithic microwave integrated circuit (MMIC) design. In this paper, we have proposed an easy and simple model parameter extraction method of wide-band on-chip inductor. The simple extraction methodology is applied to extract parameters from the measured S-parameters of spiral inductors fabricated with 0.18-/spl mu/m CMOS technology. Model prediction shows excellent agreement with the measured data over a wide frequency region. Also, the model can be easily integrated in SPICE-compatible simulators because all the elements are frequency independent. This method will provide practical and useful circuit parameters for MMIC design.

Complete high-frequency thermal noise modeling of short-channel MOSFETs and design of 5.2-GHz low noise amplifier

Taking a velocity saturation effect and a carrier heating effect in the gradual channel region, complete thermal noise modeling of short-channel MOSFETs including the induced gate noise and its correlation coefficients is presented and verified extensively with experimentally measured data. All of the four noise models have excellently predicted experimental data with maximal error less than 10% for the deep-submicron MOSFETs. Using these models and a simultaneous matching technique for both optimal noise and power, a low noise CMOS amplifier optimized for 5.2-GHz operation has been designed and fabricated. Experiments using an external tuner show that both NF/sub 50/ and NF/sub min/ are very close to 1.1 dB, which is an excellent figure of merit among reported LNAs.

A high speed and low power SOI inverter using active body-bias

We propose a new high speed and low power SOI inverter that can operate with efficient body-bias control and free supply voltage. The performance of the proposed circuit is evaluated by both the BSIM3SOI circuit simulator and the ATLAS device simulator, and then compared with other reported SOI circuits. The proposed circuit is shown to have excellent characteristics. At the supply voltage of 1.5V, the proposed circuit operates 27% faster than the conventional SOI circuit with the same power dissipation.

A -119.2 dBc/Hz at 1 MHz, 1.5 mW, fully integrated, 2.5-GHz, CMOS VCO using helical inductors

This letter presents an implementation to reduce area occupation in designing voltage-controlled oscillators (VCOs) using a filtering technique. We applied a helical inductor to the noise filter in a 2.5-GHz CMOS VCO to reduce area occupation. Because a helical inductor has less area occupation, a small silicon area was achieved. This VCO operates in the 2.5-GHz band with power consumption of 1.5 mW and phase noise of -119.2 dBc/Hz at 1-MHz. Our VCO displays an excellent performance of phase noise in relation to power consumption.

Simple Wide-Band Metal-Insulator-Metal (MIM) Capacitor Model for RF Applications and Effect of Substrate Grounded Shields

In this paper, we propose a simple wide-band metal-insulator-metal (MIM) capacitor model incorporating the skin effect in the gigahertz regions. The proposed model accurately describes the frequency-dependent series resistance over a wide range of frequencies and hence enables the quality factor of the MIM capacitor to be predicted with high accuracy in the multi-GHz frequency regime. Since the proposed model consists of frequency-independent lumped elements, it can be easily implemented in simulation program with integrated circuit emphasis (SPICE)-compatible simulators. We also demonstrate the scalability of the proposed model for different device geometries. In addition, we present the characterized results for MIM capacitors under various substrate conditions including different shield materials.

A Fully Integrated Low-Power High-Coexistence 2.4-GHz ZigBee Transceiver for Biomedical and Healthcare Applications

A fully integrated low-power high-coexistence 2.4-GHz ZigBee transceiver implemented in 90-nm CMOS technology is demonstrated. The two-point direct-modulation with a fractional- N synthesizer is adopted in the transmitter architecture. The transmitter can provide high output power of +9 dBm and excellent error vector magnitude of 5.1%. The direct conversion is used in receiver for simplicity and -97-dBm minimum receiver sensitivity is achieved. Current consumptions for a TX at +9-dBm output power and for an RX are 28.4 and 15.4 mA, respectively. Excellent coexistence is presented through wireless local area network interferer rejection performance.

A miniaturized low-power wireless remote environmental monitoring system using microfabricated electrochemical sensing electrodes

In this paper we report a miniaturized low-power wireless remote environmental monitoring system. This system has been developed for the on-site monitoring of water pollution by heavy metal ions. The system is composed of an electrochemical sensor module using microfabricated electrodes for detecting heavy-metal contamination in sample water; a custom potentiostat module (including readout circuitry, analog-to-digital converter and microcontroller); and an RF module for sending detected signals to a base station through wireless communication.

Active and Passive RF Device Compact Modeling in CMOS Technoloies

A new method for extracting pi-type substrate resistance model of RF MOSFETs based on 3-port measurement is presented. Using NQS and macro-model with extracted substrate components, it is verified that the new substrate resistance model is accurate. Also, temperature dependent macro model is developed. An analytical high frequency thermal noise model for short-channel MOSFETs which covers all operating regions is developed. A simple wide-band model for on-chip inductors on silicon is presented. Finally, an RF model of an accumulation-mode MOS varactor is presented