This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

The thermal behavior of trench-isolated bipolar transistors is thoroughly investigated. Fully 3D numerical simulations are performed to analyze the impact of all technological parameters of interest. Based on numerical results, a novel strategy to analytically evaluate the temperature field is proposed, which accounts for the heat propagation through the trench and the nonuniform heat flux distribution over the interface between the silicon box surrounded by trench and the underlying substrate. The resulting model is proved to compare with numerical simulations more favorably than the other approaches available from the literature. As a consequence, it can be employed for an accurate, yet fast evaluation of the thermal resistance of a trench-isolated device as well as of the temperature gradients within the silicon box.

Analytical modeling and numerical simulations of the thermal behavior of trench-isolated bipolar transistors

Evaluation of thermal balancing techniques in InGaP/GaAs HBT power arrays for wireless handset power amplifiers

Multi-finger power SiGe heterojunction bipolar transistors (HBTs) with emitter ballasting resistor and non-uniform finger spacing are fabricated, and temperature profiles of them are measured. Experimental results show that both of them could improve the temperature profile compared with an HBT which has uniform finger spacing. For the HBT with emitter ballasting resistor, the ability to lower the peak temperature is weakened as power increases. However, for the HBT with non-uniform finger spacing, the ability to improve temperature profile is kept over a wide biasing range. Therefore, the experimental results directly prove that the technique of non-uniform finger spacing is a better method for enhancing the thermal stability of power HBTs over a wide biasing range.

Multi-finger power SiGe HBTs for thermal stability enhancement over a wide biasing range

Structure optimization of multi-finger power SiGe HBTs for thermal stability improvement

A design methodology of broadband LNA (low noise amplifier) for convenient cascade application is proposed. This method solved two main problems in cascade LNA, i.e. the impedance match between two same modules and the stability after cascade. The single stage LNA has a good performance with over 10 dB of S21, the typical 2.5-2.7 dB of the NF (noise figure) in 1-4 GHz band, and it is unconditionally stable in the whole band. Especially, S11 is approximately equal to S22 at any frequency point. This characteristic can make a good match between two same modules. The simulation results show that the LNA with directly cascade of two same single modules can also achieve good performance in 1-4 GHz, the NF keeps nearly unchanged, S22 is two times larger than the single one, and the whole LNA is unconditionally stable, S11 and S22 decrease, and Sn is also almost equal to S22 at any frequency point.

A 1-4GHz LNA for Convenient Cascade Application

For power bipolar transistors, the emitter-ballasting-resistor is usually used to improve the thermal stability. However, the ballasting-resistors degrade the output power, power gain, power-added-efficiency (PAE) of the transistor. In this paper, the thermal stability can be improved substantially by adjusting either the spacing or length of the emitter fingers without using ballasting resistors. The temperature rise at the device center of the space-adjusted HBT is suppressed by reducing heat flow from adjacent fingers, and that of the length-adjusted HBT is suppressed by reducing heat generation in the region

Improvement of thermal stability of multi-finger power SiGe HBTs using emitter-ballasting-resistor-free designs

An effective method for enhancing thermal stability of a multi-emitter power heterojunction bipolar transistor (HBT) has been presented. The method employs the segmented emitter structure rather than the traditional non-segmented structure to suppress the junction temperature rise and reduce the thermal resistance. A suitable thermal model, which includes various thermal resistances of the different components, is built for the segmented multi-emitter HBT. Using this model, the thermal simulation for a ten-finger power SiGe HBT with segmented emitter structure is performed by ANSYS software. Considering the precision of the simulation and the restriction of ANSYS software, this study proposes two steps simulation method: first substrate simulation and second active region simulation. The three-dimensional temperature distribution on emitter fingers is obtained. Compared with non-segmented structure, the maximum junction temperature, thermal resistance of the power HBT with improved structure is significantly lower as expected, and the thermal stability is enhanced.

Thermal Analysis of Power SiGe Heterojunction Bipolar Transistor with Novel Segmented Multi-emitter Structure

A multi-finger power SiGe heterojunction bipolar transistor (HBT) with non-uniform finger spacing was fabricated to improve thermal stability.Experimental results show that the peak temperature is reduced by 22K compared with that of an HBT with uniform finger spacing in the same operating conditions.The temperature profile across the device can be improved at different biases for the same HBT with non-uniform finger spacing.Because of the decrease in peak temperature and the improvement of temperature profile,the power SiGe HBT with non-uniform spacing can operate at higher bias and hence has higher power handling capability.

Wang Yang

Papers

Multi-finger power SiGe HBTs for thermal stability enhancement over a wide biasing range

A 1-4GHz LNA for Convenient Cascade Application

Improvement of thermal stability of multi-finger power SiGe HBTs using emitter-ballasting-resistor-free designs

Thermal Analysis of Power SiGe Heterojunction Bipolar Transistor with Novel Segmented Multi-emitter Structure

Multi-Finger Power SiGe HBT with Non-Uniform Finger Spacing