Ik-Hyun Song

A compact, low loss, wideband digital step attenuator (DSA) is presented. The proposed DSA utilizes amplitude/phase-compensated T-type attenuator cells, in which the locations of poles and zeros are manipulated for minimizing variations in attenuation and phase. In addition, the reduced T-type attenuator cells that eliminate series switch transistors are used to achieve low insertion loss (IL). These techniques provide wideband (dc-20 GHz) operation for the DSA, with significantly decreased atte

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A SiGe RF low-noise amplifier (LNA) with built-in tolerance to single-event transients is proposed. The LNA utilizes an inverse-mode SiGe HBT for the common-base transistor in a cascode core. This new cascode configuration exhibits reduced transient peaks and shorter transient durations compared to the conventional cascode one. The improved SET response was verified with through-wafer two-photon absorption pulsed-laser experiments and supported via mixed-mode TCAD simulations. In addition, analy

The capability of inverse-mode (IM) silicon- germanium (SiGe) heterojunction bipolar transistors (HBTs) for the mitigation of single-event transients (SETs) under large-signal operation was investigated in an RF down-conversion single- balanced mixer using a through-wafer, two-photon absorption pulsed-laser beam experiment and TCAD heavy-ion simulations. The IM SiGe HBTs replace conventional forward-mode (FM) SiGe HBTs in the differential pair, which provides full current steering for frequency

A power divider/combiner circuit, which simultaneously achieves wide bandwidth, flat gain characteristics, and bidirectional operation, is proposed for multichannel broadband system applications. The proposed circuit utilizes cascode-based bidirectional amplifier cores, which steer the operation modes between a divider and a combiner depending on the control input, and a two-stage distributed-amplifier topology with artificial transmission lines. Implemented in a 130-nm silicon-germanium BiCMOS

Best practice in mitigation strategies for single-event transients (SETs) in radio-frequency (RF) receiver modules is investigated using a variety of integrated receivers utilizing inverse-mode silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The receivers were designed and implemented in a 130-nm SiGe BiCMOS technology platform. In general, RF switches, low-noise amplifiers (LNAs), and downconversion mixers utilizing inverse-mode SiGe HBTs exhibit less susceptibility to SETs

Abstract In this paper, design consideration of the cascode configuration in low‐noise amplifiers (LNA) using 0.13‐μm CMOS technology is presented. Performance factors of LNAs such as signal power gain, noise factor, and power consumption are analytically expressed in device parameters from its small‐signal equivalent circuit. The effect of the common‐gate transistor in each performance factor is evaluated at the target frequency of 17‐GHz ISM band. At this frequency, power gain and noise factor

A cascode configuration with inverse-mode (IM) common-emitter silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) is proposed for the mitigation of single-event transients (SETs) in low-noise amplifiers (LNAs). Conventionally, despite their SET-mitigation capability, IM SiGe HBTs have been considered to be unsuitable for active gain stages due to severe degradation in RF performance. However, with the benefits of aggressive technology scaling, the high frequency performance of IM

An asymmetric, broadside-coupled Marchand balun for wideband millimeter wave applications is presented. The balun based on the modified off-center frequency method achieves 34–110 GHz operation bandwidth and exhibits minimum insertion loss of 4.7 dB at 54 GHz. To the author's best knowledge, this is the widest operational bandwidth among the recently published millimeter wave baluns in silicon technology.

The benefits of using p-n-p silicon-germanium (SiGe) heterojuction bipolar transistors (HBTs) in radio frequency (RF) circuits for the mitigation of single-event transients (SETs) have been investigated. As a representative circuit example, p-n-p SiGe-HBT RF single-pole single-throw (SPST) switches have been designed in a complementary SiGe BiCMOS platform. The fabricated p-n-p-based RF switches provide comparable RF performance to n-p-n-based switches. In terms of SET transient peaks and durati

Single-event transient (SET)-hardened SiGe HBT RF single-pole single-throw (SPST) switches were designed and fabricated for the first time. TCAD-based heavy-ion simulations and two-photon absorption (TPA) laser-induced beam experiments were used to optimize the switch core configuration for SET mitigation. Among different configurations, the reverse-connected series and shunt device core, where both emitter terminals are connected to the output, exhibits the smallest transient peaks and shortest

The cryogenic performance of radiation-hardened radio-frequency (RF) low-noise amplifiers (LNAs) is presented. The LNA, which was originally proposed for the mitigation of single-event transients (SETs) in a radiation environment, uses inverse-mode silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) in its core cascode stages. In this prototype, the upper common-base SiGe HBT is configured in inverse mode for balanced RF performance and reduced SET sensitivity. In order to better

An active bi-directional power dividier/combiner circuit based on a distributed topology is proposed. The use of bi-directional amplifiers (BDAs) provides both dividing and combining functions within the same circuit. By utilizing a distributed topology composed of BDAs and artificial transmission lines, a wide operational bandwidth (2–22 GHz) and a large, flat power gain (9 dB) were achieved under DC power consumption of 100 mW. The maximum amplitude and phase imbalances were 0.7 dB and 3°, res

In this work, the design of a wideband low-noise amplifier (LNA) using a resistive feedback network is proposed for potential multi-band sensing, communication, and radar applications. For achieving wide operational bandwidth and flat in-band characteristics simultaneously, the proposed LNA employs a variety of circuit design techniques, including a voltage-current (shunt-shunt) negative feedback configuration, inductive emitter degeneration, a main branch with an added cascode stage, and the sh

It has been known that negative feedback loops (internal and external) in a SiGe heterojunction bipolar transistors (HBT) DC current mirrors improve single-event transient (SET) response; both the peak transient current and the settling time significantly decrease. In the present work, we demonstrate how radiation hardening by design (RHBD) techniques utilized in DC bias blocks only (current mirrors) can also improve the SET response in AC signal paths of switching circuits (e.g., current-mode l