S. Yoo

RF power amplifier integration in CMOS technology

This paper explores different levels of integration for CMOS RF power amplifiers, including integration fully on chip, integration with LTCC passive components, and integration with off-chip components. At 1.9 GHz, the fully on-chip integrated CMOS PA can deliver 20 dBm output power with 16% efficiency. Because the LTCC inductors have much higher Q than the on-chip inductors, the CMOS PA integrated with passive components embedded in LTCC can improve the output power and efficiency to 24 dBm and 32% at 1.9 GHz, respectively. The 2.4 GHz Bluetooth PA with discrete passive components for output matching exhibits 22 dBm output power and 44% efficiency. To our knowledge, this paper reports the first development of fully on-chip integrated and LTCC hybrid CMOS power amplifiers.

Broadband highly integrated LTCC front-end module for IEEE 802.11a WLAN applications

This paper presents the design, development and measurement of a highly-integrated and high linearity RF front-end module with integrated filter for IEEE 802.11a wireless LAN applications. The developed front-end MMIC includes LNA, PA, and SPDT switch integrated on a single chip in a commercial GaAs MESFET process. An embedded 3-D band pass filter has been integrated on the front-end module using LTCC technology. The performance of the front-end module is compliant to the HiPERLAN-I and IEEE 802.11a RF standards. The LNA exhibits 16.5 dB of gain, 2.1 dB of noise figure and IIP3 of 2.8dBm. The PA shows the 24 dBm output power and IM3 of better than 25dBc. The SPDT switch demonstrates 1.2 dB of insertion loss and 28dBm of input P1dB. To the best of our knowledge, this is the first report on C-band PA-LNA-Switch integrated on a single chip with embedded LTCC filter.

A C-band low power high dynamic range GaAs MESFET low noise amplifier

A low power high dynamic range C-band GaAs MESFET low noise cascode amplifier is presented. An accurate small signal model and a noise model of the device based upon measurement are developed for the LNA design. At 5 GHz, a 50 /spl Omega/ noise figure of 1.9 dB and an IIP3 of 5 dBm are measured at a power consumption of 13.2 mW from a 3 V DC supply. The measurement results show good agreement with simulation results. This design has the highest IIP3 compared to other GaAs MESFET LNAs at this frequency range.

Development of an integrated Bluetooth RF transceiver module using multi-layer system on package technology

We present the development of an integrated Bluetooth transceiver module using a commercial low temperature co-fired ceramic (LTCC) process. The developed module contains a power amplifier (PA), low noise amplifier (LNA), mixer, balun, band select filter and integrated antenna. The MMICs and passives are developed using a commercial 0.24 /spl mu/m CMOS process and LTCC respectively. The power amplifier is capable of providing an output power of 20 dBm for the Bluetooth class 1 specification. To the best of our knowledge, this work presents the first report of module with integrated antennas.

A 2.4-GHz radio front end in RF system-on-package technology

Voltage-controlled oscillators (VCOs) are critical components for signal generation and frequency selection in RF/microwave transceivers. Recently, there has been considerable interest in monolithic integration of inductance-capacitance (LC) tank oscillators for highly integrated RF transceivers [1]. Technologies such as Si complimentary metal-oxide-semiconductor (CMOS) and Si/SiGe BiCMOS are of interest in light of the potential for integration with digital functions. The operation of an oscillator can be described using the concept of “negative resistance.” In an oscillator, an active network with negative transconductance, −GM, is connected to an LC-tank circuit with an equivalent parallel resistance, RP. The equivalent negative resistance (1/−GM) looking back into the transconductor is chosen to cancel the equivalent parallel resistance of the tank circuit. RP is obviously related to the quality factor Q of the L and C components. In Si technologies, the Q of the inductor is usually the limiting factor. Differential topologies are advantageous in integrated circuits (ICs) because they offer common-mode rejection. Therefore, differential circuits are less susceptible to supply noise present in on-chip power rails. Many RF integrated circuits (RFICs) utilize double-balanced Gilbert-cell mixers because they offer conversion gain while minimizing local oscillator (LO)/intermediate frequency (IF) feedthrough and even-order mixing products. Differential VCO topologies avoid the need for single-ended to differential conversion circuitry for the LO drive of a Gilbert-cell mixer. Figure 1 shows a differential CMOS complementary −GM oscillator [2], [3]. In this case, the negative resistance seen by the tank is given by

Temperature dependent MOSFET RF large signal model incorporating self heating effects

We present a new temperature dependent large signal model with self heating and ambient temperature effects for power MOSFETs developed from on-wafer pulse I-V measurements at different ambient temperatures. The MOSFET channel current equation in the model has temperature parameters and continuity in high order derivatives to predict temperature effects and harmonics accurately. The data from the model with self heating effects demonstrates good agreement with measured S parameters and power characteristics including gain, efficiency, harmonic components and intermodulation powers in class AB operation.

A high efficiency 0.25 /spl mu/m CMOS PA with LTCC multi-layer high-Q integrated passives for 2.4 GHz ISM band

We present the first high efficiency CMOS power amplifier utilizing fully integrated multi-layer Low Temperature Co-fired Ceramic (LTCC) high-Q passives for 2.4 GHz ISM band applications. The inductor and capacitor library was built in a multi-layer LTCC board using a compact topology. An inductor Q-factor as high as 110 with a self-resonant-frequency (SRF) as high as 12 GHz was demonstrated. Measured results of the CMOS-LTCC PA show 45% power added efficiency, 23 dBm output power and 18 dB gain at 2.4 GHz with a low 2.5 V drain supply voltage. This result is the first significant step toward a compact transceiver module development utilizing fully integrated multi-layer LTCC high-Q passives and a deep submicron (0.25 /spl mu/m) CMOS technology.

An improved deep sub-micron MOSFET RF nonlinear model with new breakdown current model and drain to substrate nonlinear coupling

An improved deep sub-micron (0.25 /spl mu/m) MOSFET RF large signal model that incorporates a new breakdown current model and drain to substrate nonlinear coupling was developed and investigated with various experiments. An accurate breakdown model is required for a deep submicron MOSFET due to its relatively low breakdown voltage. For the first time, this improved RF nonlinear model incorporates the breakdown voltage turnover behavior into a continuously differentiable channel current model, and the new nonlinear coupling network between the drain and lossy substrate. The robustness of the model was verified with measured pulsed I-V, S-parameters, power characteristics and inter-modulation distortions at different input and output matching conditions, operating biases, and frequencies.

A 5.8 GHz OFDM GaAs MESFET MMIC chip set

This paper presents the implementation of a 5.8 GHz GaAs MESFET MMIC transceiver chip set compatible with the OFDM standard. The receiver is designed for low noise figure and high IIP3. The transmitter is designed to satisfy high peak-to-average power ratio. This design matches closely with the requirements for 5.8 GHz wireless LAN applications. To the best of our knowledge, this research represents the first reported implementation of the OFDM standard at 5.8 GHz.

A highly-integrated low-power direct conversion receiver MMIC for broadband wireless applications

In this paper, we present a highly integrated low-power direct conversion receiver MMIC for broadband wireless applications at C-band. This receiver chip is fabricated in a 0.6 /spl mu/m commercial GaAs MESFET process and operates on only 90 mW of dc power consumption. Using an integrated switched LNA and direct-coupled baseband amplifiers, this receiver demonstrates a conversion gain of 25 dB, NF of 6.7 dB, dc offset below -70 dBm, IIP2 of +20 dBm, and IIP3 of -15 dBm in the high-gain mode and +15 dBm in the low-gain mode at 5.8 GHz.