Indium-phosphide Double-heterojunction Bipolar Transistor Research Articles

A Novel Design Method of SOF for InP DHBT ECL and CML Static Frequency Dividers

In this letter, we present a novel analysis and design approach of self-oscillation frequency (SOF) for 0.8-μm indium phosphide (InP) double-heterojunction bipolar transistor (DHBT) emitter-coupled logic (ECL) and current-mode logic (CML) static frequency dividers. SOF of ECL and CML dividers is designed to be the maximum value after theoretical analysis and multiparameter optimization. The results show that the SOF of the ECL and CML divider is 62 and 37.5 GHz, respectively. With sinusoidal waveform input, the operating frequency range of the ECL divider is from 0.1 to 65 GHz, and CML is from 0.1 to 55 GHz, while the cut-off frequency f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> is 150 GHz. For ECL, the f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> utilization of SOF (SOF /f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> ) is 0.413, and CML is 0.25. These are the maximum SOF results that can be designed for the two dividers under the same design conditions.

106‐GHz bandwidth InP DHBT linear driver with a 3‐V ppdiff swing at 80 GBd in PAM‐4

This Letter reports the design, fabrication and characterisation of a new differential linear driver, fabricated in the III-V Lab 0.7- emitter width indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. Large-signal electrical characterisation shows 80-GBd symbol-rate four-level pulse amplitude (PAM-4) modulation conjugated with a driver output swing of 3-Vppdiff and a 0.74-W power consumption. Thus resulting in a 1.22-GBd driving efficiency, the highest in over 70-GBd drivers' state-of-the-art, at that date. Accordingly, S-parameter measurements of the standalone linear driver exhibit the highest gain-bandwidth product of 556 GHz, in that current state-of-the-art.

A 110–170-GHz Multi-Mode Transconductance Mixer in 250-nm InP DHBT Technology

A novel full D-band (110–170 GHz) multi-mode transconductance down-converter mixer is realized in a 250-nm indium–phosphide double heterojunction bipolar transistor technology. A single-balanced topology is chosen and an active power combiner for the RF and the local oscillator (LO) signals’ combination is used. The designed mixer is feasible to work at $\, \times \,$ 1, $\, \times \,$ 2, $\, \times \,$ 3, $\, \times \,$ 4 subharmonically LO-pumped mixing modes with relatively low LO powers of 0, ${-}{\hbox{1}}$ , 5, and 6 dBm, respectively. The measured conversion gain achieves typical values of ${-}{\hbox{3}}$ , ${-}{\hbox{1}}$ , ${-}{\hbox{5}}$ , and ${-}{\hbox{4}}$ dB over the full D-band while the best noise figures of 12, 13.5, 18.5, and 19 dB are obtained, respectively. Through the multi-mode operation in terms of subharmonic LO-pump-frequency, the designer can make a tradeoff between LO frequency, LO power, and noise figure.

Polymer enabled 100 Gbaud connectivity for datacom applications

Polymers hold the promise for ultra-fast modulation of optical signals due to their potential for ultra-fast electro-optic (EO) response and high EO coefficient. In this work, we present the basic structure and properties of an efficient EO material system, and we summarize the efforts made within the project ICT-POLYSYS for the development of high-speed transmitters based on this system. More specifically, we describe successful efforts for the monolithic integration of multi-mode interference (MMI) couplers and Bragg-gratings (BGs) along with Mach–Zehnder modulators (MZMs) on this platform, and for the hybrid integration of InP active elements in the form of laser diodes (LDs) and gain chips (GCs). Using these integration techniques and the combination of the hybrid optical chips with ultra-fast indium phosphide double heterojunction bipolar transistor (InP-DHBT) electronics, we develop and fully package a single 100Gb/s transmitter and a 2×100Gb/s transmitter that can support serial operation at this rate with conventional non-return-to-zero on-off-keying (NRZ-OOK) modulation format. We also present the experimental evaluation of the devices, validating the efficiency of the monolithic and hybrid integration concepts and confirming the potential of this technology for single-lane 100Gb/s optical connectivity in data-center network environments. Results from transmission experiments to this end include the achievement of BER close to 6·10−9 in B2B configuration, the achievement of BER lower than 10−7 for propagation over standard single-mode fiber (SSMF) with total length up to 1000m, and the achievement of BER at the level of 10−5 after 1625m of SSMF. Finally, plans for the use of the EO polymer system in a more complex hybrid integration platform for high-flexibility/high-capacity transmitters are also outlined.

Fully Integrated D-Band Direct Carrier Quadrature (I/Q) Modulator and Demodulator Circuits in InP DHBT Technology

This paper presents design and characterization of D-band (110–170 GHz) monolithic microwave integrated quadrature up- and down-converting mixer circuits with on-chip RF and local oscillator (LO) baluns. The circuits are fabricated in 250-nm indium–phosphide double heterojunction bipolar transistor technology. The mixers require an external LO signal and can be used as direct carrier quadrature modulator and demodulator to implement higher order quadrature amplitude modulation formats. The up-converter has a single-sideband (SSB) conversion gain of 6 dB with image and LO suppression of 32 and 27 dBc, respectively. The chip can provide maximum output RF power of 2.5 dBm, a third-order output intercept point of 4 dBm, and consumes 78-mW dc power. The down-converter exhibits 14-dB SSB conversion gain with 25-dB image rejection ratio, and 11.5-dB SSB noise figure. The chip consumes 74-mW dc power and can deliver maximum output IF power of 4 dBm. Both chips have the same size with active area of 560 $\mu$ m $\,\times\,$ 440 $\mu$ m including the RF and LO baluns.