James F. Buckwalter
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View article: Analog coherent link with expanded link budget from integrated lasers and transmission through an O-band wavelength selective switch
Analog coherent link with expanded link budget from integrated lasers and transmission through an O-band wavelength selective switch Open
We report what is believed to be the first unamplified analog coherent link using heterogeneously integrated lasers in both the TX and RX. The link achieves a 10 dB fiber-to-fiber link budget while operating with BER below the KP-4 FEC thr…
View article: Dual-Polarization Optical Costas Loop for DSP-Free Homodyne Short-Reach Links
Dual-Polarization Optical Costas Loop for DSP-Free Homodyne Short-Reach Links Open
View article: Dynamic Power Splitting in a Hybrid Common-Emitter/Common-Base Doherty Amplifier for High Average Efficiency Above 100 GHz Using an InP HBT Process
Dynamic Power Splitting in a Hybrid Common-Emitter/Common-Base Doherty Amplifier for High Average Efficiency Above 100 GHz Using an InP HBT Process Open
View article: Dual-polarization O-band silicon photonics transmitter with an integrated tunable laser, Mach-Zehnder modulators, and SOAs
Dual-polarization O-band silicon photonics transmitter with an integrated tunable laser, Mach-Zehnder modulators, and SOAs Open
Presented is an O-band silicon photonics dual-polarization coherent/IMDD modulator integrated with semiconductor optical amplifiers and tunable laser to enhance the short-reach link budget. The laser demonstrated output power >6 dBm and a …
View article: Mixed domain coherent link with electrically reconfigurable IMDD and coherent modes for O-band data center applications
Mixed domain coherent link with electrically reconfigurable IMDD and coherent modes for O-band data center applications Open
We report the first O-band link with electrically reconfigurable intensity-modulation direct-detection (IMDD) and coherent operation using custom silicon photonic chips packaged with commercial electronic chips. Transmission below the KP4-…
View article: Free Space Dielectric Techniques for Diamond Composite Characterization
Free Space Dielectric Techniques for Diamond Composite Characterization Open
Compact millimeter-wave arrays demand novel packaging solutions that feature low-cost dielectric materials with significant thermal conductivity (100 W/m ⋅ K). To characterize the permittivity and loss tangent of the dielectric materials a…
View article: A Monolithic O-Band Coherent Optical Receiver for Energy-Efficient Links
A Monolithic O-Band Coherent Optical Receiver for Energy-Efficient Links Open
A 1310-nm (O-band) coherent optical Link is demonstrated for short-range optical interconnects that operate to 56-GBd symbol rate (SR) (112 Gbps) with FEC-acceptable BER. The coherent optical receiver (CORX) leverages a monolithic 45-nm CM…
View article: Guest Editorial Introduction to the Special Section on the 2023 IEEE International Solid-State Circuits Conference (ISSCC)
Guest Editorial Introduction to the Special Section on the 2023 IEEE International Solid-State Circuits Conference (ISSCC) Open
This Special Section of IEEE JOURNAL OF SOLID-STATE CIRCUITS (JSSC) highlights outstanding papers presented at the 2023 IEEE International Solid-State Circuits Conference (ISSCC), which was held from February 19 to 23, 2023, in San Francis…
View article: A Survey of GaN HEMT Technologies for Millimeter-Wave Low Noise Applications
A Survey of GaN HEMT Technologies for Millimeter-Wave Low Noise Applications Open
This article presents a set of measured benchmarks for the noise and gain performance of six different millimeter-wave (mm-wave) gallium nitride (GaN) high electron mobility transistor (HEMT) technologies fabricated at four different found…
View article: Integrated SOAs enable energy-efficient intra-data center coherent links
Integrated SOAs enable energy-efficient intra-data center coherent links Open
Coherent optical links are becoming increasingly attractive for intra-data center applications as data rates scale. Realizing the era of high-volume short-reach coherent links will require substantial improvements in transceiver cost and p…
View article: High-Efficiency 200-GHz Neutralized Common-Base Power Amplifiers in 250-nm InP HBT
High-Efficiency 200-GHz Neutralized Common-Base Power Amplifiers in 250-nm InP HBT Open
The analysis, design, and measurement of two Indium Phosphide (InP) heterojunction bipolar transistor (HBT) power amplifier (PA) designs are presented at G-band with record efficiency. A pseudo-differential common-base (CB) stage with neut…
View article: Technical Committee 14 Report [MTT-S Society News]
Technical Committee 14 Report [MTT-S Society News] Open
Provides society information that may include news, reviews or technical notes that should be of interest to practitioners and researchers.
View article: IEEE Transactions on Terahertz Science and Technology Publication Information
IEEE Transactions on Terahertz Science and Technology Publication Information Open
View article: Coupled Embedding Networks for 7-dB Gain-per-Stage at 130–140 GHz in a 20-dBm Gallium Nitride Power Amplifier
Coupled Embedding Networks for 7-dB Gain-per-Stage at 130–140 GHz in a 20-dBm Gallium Nitride Power Amplifier Open
We propose a coupled embedding network (CEN) as a portable, robust design technique to simultaneously introduce gain boosting and loadline matching in millimeter-wave power (mm-wave) amplifiers (PAs). The approach uses directional couplers…
View article: IEEE Transactions on Terahertz Science and Technology Publication Information
IEEE Transactions on Terahertz Science and Technology Publication Information Open
View article: IEEE Transactions on Terahertz Science and Technology
IEEE Transactions on Terahertz Science and Technology Open
View article: IEEE Transactions on Terahertz Science and Technology
IEEE Transactions on Terahertz Science and Technology Open
View article: IEEE Transactions on Terahertz Science and Technology
IEEE Transactions on Terahertz Science and Technology Open
View article: A 50-GBaud QPSK Optical Receiver With a Phase/Frequency Detector for Energy-Efficient Intra-Data Center Interconnects
A 50-GBaud QPSK Optical Receiver With a Phase/Frequency Detector for Energy-Efficient Intra-Data Center Interconnects Open
This paper describes the energy-efficient realization of a QPSK optical receiver (CoRX) for short-reach intra-datacenter interconnects based on analog coherent detection. The CoRX comprises inphase and quadrature channels for each polariza…
View article: Broadband, High-Linearity Switches for Millimeter-Wave Mixers Using Scaled SOI CMOS
Broadband, High-Linearity Switches for Millimeter-Wave Mixers Using Scaled SOI CMOS Open
This work demonstrates new circuit techniques in distributed-stacked-complimentary (DiSCo) switches that enable picosecond switching speed in RF CMOS SOI switches. By using seriesstacked devices with optimized gate impedance and voltage sw…
View article: Understanding Energy Efficiency and Interference Tolerance in Millimeter Wave Receivers
Understanding Energy Efficiency and Interference Tolerance in Millimeter Wave Receivers Open
Power consumption is a key challenge in millimeter wave (mmWave) receiver front-ends, due to the need to support high dimensional antenna arrays at wide bandwidths. Recently, there has been considerable work in developing low-power front-e…
View article: Fundamental limits of high-efficiency silicon and compound semiconductor power amplifiers in 100-300 GHz bands
Fundamental limits of high-efficiency silicon and compound semiconductor power amplifiers in 100-300 GHz bands Open
This paper reviews the requirements for future digital arrays in terms of power amplifier requirements for output power and efficiency and the device technologies that will realize future energy-efficient communication and sensing electron…
View article: INTREPID program: technology and architecture for next-generation, energy-efficient, hyper-scale data centers [Invited]
INTREPID program: technology and architecture for next-generation, energy-efficient, hyper-scale data centers [Invited] Open
The INTREPID program is developing power-efficient coherent optics for package-level integration with future switch integrated circuits as a path to realizing higher-radix switches for flatter networks. The link architecture is underpinned…
View article: Session 26 Overview: RF Power-Amplifier and Front-End Techniques
Session 26 Overview: RF Power-Amplifier and Front-End Techniques Open
RF PAs and front-end building blocks are critical for the output power, noise, power-efficiency, out-of-band rejection, and antenna impedance tuning of wireless transceivers. The first three papers in this session cover mm-wave PAs with ef…
View article: IMS 2020 Guest Editorial
IMS 2020 Guest Editorial Open
This Special Issue of the IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES (TMTT) is comprised of expanded articles from the 2020 IEEE International Microwave Symposium (IEEE IMS) held virtually on August 4–6, 2020, in response to the …
View article: Towards Energy Efficient Mobile Wireless Receivers Above 100 GHz
Towards Energy Efficient Mobile Wireless Receivers Above 100 GHz Open
Wireless communication above 100 GHz offers the potential for massive data rates and has attracted considerable attention for Beyond 5G and 6G systems. A key challenge in the receiver design in these bands is power consumption, particularl…
View article: 2020: A Year to Envision the Future of the IMS
2020: A Year to Envision the Future of the IMS Open
This year provides an excellent opportunity to evaluate where the IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS) is headed. The future decade offers many exciting developments in commercial app…
View article: A Case for Digital Beamforming at mmWave
A Case for Digital Beamforming at mmWave Open
Due to the heavy reliance of millimeter-wave (mmWave) wireless systems on directional links, beamforming (BF) with high-dimensional arrays is essential for cellular systems in these frequencies. How to perform the array processing in a pow…
View article: Forward bias operation of silicon photonic Mach Zehnder modulators for RF applications
Forward bias operation of silicon photonic Mach Zehnder modulators for RF applications Open
In this paper, we demonstrate that forward bias (+0.9V) of a high-speed silicon (Si) optical Mach-Zehnder modulator (MZM) increases the radio-frequency (RF) link gain by 30 dB when compared to reverse bias operation (-8V). RF applications …
View article: Technical Program Committee
Technical Program Committee Open