Jonathan P. Comeau

A Silicon-Germanium Receiver for X-Band Transmit/Receive Radar Modules

This work investigates the potential of commercially-available silicon-germanium (SiGe) BiCMOS technology for X-band transmit/receive (T/R) radar modules, focusing on the receiver section of the module. A 5-bit receiver operating from 8 to 10.7 GHz is presented, demonstrating a gain of 11 dB, and average noise figure of 4.1 dB, and an input-referred third-order intercept point (HP3) of -13 dBm, while only dissipating 33 mW of power. The receiver is capable of providing 32 distinct phase states from 0 to 360deg, with an rms phase error < 9deg and an rms gain error < 0.6 dB. This level of circuit performance and integration capability demonstrates the benefits of SiGe BiCMOS technology for emerging radar applications, making it an excellent candidate for integrated X-band phased-array radar transmit/receive modules.

Sources of Phase Error and Design Considerations for Silicon-Based Monolithic High-Pass/Low-Pass Microwave Phase Shifters

A comprehensive analysis of error sources in monolithic microwave phase shifters due to device size limitations, inductor parasitics, loading effects, and nonideal switches is presented. Each component utilized in the implementation of a monolithic high-pass/low-pass phase shifter is analyzed, and its influence on phase behavior is shown in detail, with an emphasis on the net impact on absolute phase variation. The design of the individual phase-shifter filter sections and the influence of bit ordering on overall performance are also addressed. An X-band 5-bit phase shifter fabricated in a 200-GHz SiGe HBT BiCMOS technology platform is used to validate this analysis and our design methodology and achieves an absolute rms phase error of 4deg and relative rms phase error of 3deg for operation from 8.5 to 10.5 GHz

Substrate Engineering Concepts to Mitigate Charge Collection in Deep Trench Isolation Technologies

Delayed charge collection from ionizing events outside the deep trench can increase the SEU cross section in deep trench isolation technologies. Microbeam test data and device simulations demonstrate how this adverse effect can be mitigated through substrate engineering techniques. The addition of a heavily doped p-type charge-blocking buried layer in the substrate can reduce the delayed charge collection from events that occur outside the deep trench isolation by almost an order of magnitude, implying an approximately comparable reduction in the SEU cross section

A 2 mW, Sub-2 dB Noise Figure, SiGe Low-Noise Amplifier For X-band High-Altitude or Space-based Radar Applications

This paper presents a low-power X-band low-noise amplifier (LNA) implemented in silicon-germanium (SiGe) technology targeting high-altitude or space-based low-power density phased-array radar systems. To our knowledge, this X-band LNA is the first in a Si-based technology to achieve less than 2 dB mean noise figure while dissipating only 2 mW from a 1.5 V power supply. The gain of the circuit is 10 dB at 10 GHz with an IIP 3 of 0 dBm. In addition to standard amplifier characterization, the LNAs total dose radiation response has been evaluated.

Single Event Upset Mechanisms for Low-Energy-Deposition Events in SiGe HBTs

Microbeam measurements and TCAD simulations are used to examine the effects of ion angle of incidence on the charge collected from events occurring in a Silicon Germanium (SiGe) Heterojunction Bipolar Transistor (HBT). The results identify the geometrically driven charge-collection mechanisms that dominate the low LET broad beam SEU response. The deep trench isolation that surrounds the transistor significantly modulates the charge transport and, therefore, the charge collected by the collector. A new way of estimating critical charge, , for upset in SiGe HBT circuits is proposed based on TCAD simulation results and measured broadbeam data.

A 28-GHz SiGe up-conversion mixer using a series-connected triplet for higher dynamic range and improved IF port return loss

This work presents a fully integrated SiGe microwave up-conversion mixer, utilizing a new circuit topology consisting of a common-base, series-connected triplet at the IF port to achieve a significant improvement in dynamic range. This circuit functions with an IF signal of 1.25 GHz, and has an input 1-dB compression point (IP/sub 1dB/) of -6.8 dBm, for an RF output at 28 GHz. The circuit operates over a frequency range from 19 to 31 GHz, with a maximum conversion gain of 1 dB. The mixer can operate over an IF range from 1 to 10 GHz, while maintaining an IF port return loss greater than 10 dB.

Comparison of Shunt and Series/Shunt nMOS Single-Pole Double-Throw Switches for X-Band Phased Array T/R Modules

This paper compares the performance of shunt and series/shunt single-pole double-throw nMOS switches designed in a 0.13 mum SiGe BiCMOS process for X-band phased array transmit/receive modules. From 8.5 to 10.5 GHz, the worst case return loss, insertion loss, and isolation are 14.5, 1.89, and 20.5 dB, respectively, for the reflective shunt switch, and 22.2, 2.33, and 22.5 dB, respectively, for the absorptive series/shunt switch. Both switches exhibit an IIP3 of about 28 dBm and dissipate no dc power. The performance of these switches are comparable to other CMOS switches found in triple well technologies, on non-standard substrates, using special device structures, or using extra dc biases

Proton tolerance of advanced SiGe HBTs fabricated on different substrate materials

The proton tolerance of SiGe heterojunction bipolar transistors (HBTs) fabricated on a variety of substrate materials is investigated for the first time. The present SiGe HBT BiCMOS technology represents only the second commercially-available SiGe process to be reported for radiation effects. SiGe HBT dc and ac performance is compared for devices fabricated on silicon-on-insulator (SOI), low resistivity, and high resistivity silicon substrates, and all are found to be total dose tolerant to multi-Mrad radiation levels. We also compare these radiation results to those previously reported for other commercially-available SiGe technologies.

A High-Linearity 5-bit, X-band SiGe HBT Phase Shifter

This work presents a fully-integrated, 5-bit, X-band phase shifter fabricated in a commercially-available 200 GHz silicon-germanium (SiGe) HBT BiCMOS technology. This SiGe phase shifter targets high-linearity for phased-array radar applications and utilizes a SiGe HBT single-pole, double-throw switch to select between high-pass and low-pass filter sections to generate the desired phase shift. The circuit achieves a 1-dB compression point of 4.4 dBm, and an input-referred third order intercept point of 18 dBm, while dissipating 248 mW from a 2.3 V supply. The absolute phase error of the shifter was less than +/- 15 degrees from 8 GHz to 12 GHz, with an average insertion loss of -16.2 dB

A Monolithic 5-Bit SiGe BiCMOS Receiver for X-Band Phased-Array Radar Systems

This work presents a 5-bit receiver for X-band phased-array radar applications based on a commercially-available silicon-germanium (SiGe) BiCMOS technology. The receiver achieves a gain of 11 dB, an operational bandwidth from 8.0 to 10.7 GHz, an average noise figure of 4.1 dB, and an input-referred third-order intercept point (IIP3) of-13 dBm, while only dissipating 33 mW of power. The receiver also provides 32 distinct phase states from 0 to 360deg, with an rms phase error < 9deg. This level of circuit performance and integration capability demonstrates the benefits of SiGe BiCMOS technology for emerging radar applications, making it an excellent candidate for integrated X-band phased-array radar transmit/receive modules.