Showing papers by "Nils Weimann published in 2016"

SciFab -a wafer-level heterointegrated InP DHBT/SiGe BiCMOS foundry process for mm-wave applications

Abstract: We present a wafer-level heterointegrated indium phosphide double heterobipolar transistor on silicon germanium bipolar-complementary metal oxide semiconductor (InP DHBT on SiGe BiCMOS) process which relies on adhesive wafer bonding. Subcircuits are co-designed in both technologies, SiGe BiCMOS and InP DHBT, with more than 300 GHz bandwidth microstrip interconnects. The 250 nm SiGe HBTs offer cutoff frequencies around 200 GHz, the 800 nm InP DHBTs exceed 350 GHz. Heterointegrated signal sources are demonstrated including a 328 GHz quadrupling source with dBm RF output power. A common design kit for full InP DHBT/SiGe BiCMOS co-design was set up. The technology is being opened to third-party customers through IHP's multi-purpose wafer foundry interface. Microphotograph of InP DHBT / SiGe BiCMOS wafer

Multifinger Indium Phosphide Double-Heterostructure Transistor Circuit Technology With Integrated Diamond Heat Sink Layer

Abstract: The RF power output of scaled subterahertz and terahertz indium phosphide double-heterostructure bipolar transistors (InP DHBTs) is limited by the thermal device resistance, which increases with the geometrical frequency scaling of these devices. We present a diamond thin-film heat sink process aimed at the efficient removal of the heat generated in submicrometer InP HBTs. The thin-film diamond is integrated in a wafer bond process. Vertical connections are facilitated by plasma-processed contact holes through the diamond layer, metallized with electroplated gold. The process is suitable for monolithic circuit integration, amenable to the realization of high-power analog circuits in the millimeter-wave region and beyond. The thermal resistance of double-finger transistors with a 0.8- $\mu \text{m}$ emitter width could be reduced to 0.7 K/mW, while reaching the gain cutoff frequencies of $f_{T}=360$ GHz and $f_{\mathrm {max}}=350$ GHz. An integrated two-stage power amplifier with four-way power combining fabricated in this technology exhibited 20-dBm power output at 90 GHz with a bandwidth of 10 GHz.

A G-Band High Power Frequency Doubler in Transferred-Substrate InP HBT Technology

Abstract: This letter presents a G-band balanced frequency doubler with high output power, realized using a 800 nm transferred-substrate InP-HBT process. The doubler delivers $5\ {\rm dBm} \pm 3$ dBm in the range 140–220 GHz. The dc consumption is only 41 mW. To the knowledge of the authors, this is the highest output power for a wideband transistor based frequency doubler in the 140–220 GHz frequency range published so far. The results show the ability to implement a high output power G-band source in transferred-substrate InP HBT technology.

A 330 GHz active frequency quadrupler in InP DHBT transferred-substrate technology

Abstract: This paper presents a wideband 330 GHz frequency quadrupler using 0.8 µm transferred substrate (TS) InP-HBT technology. The process includes a heat-spreading diamond layer, which improves the power handling capability of the circuit. The quadrupler delivers −7 dBm output power at 325 GHz, at a DC consumption of only 40 mW, which corresponds to 0.5 % of efficiency. It achieves 90 GHz bandwidth and exhibits very low unwanted harmonics. The circuit utilizes a balanced architecture. The results demonstrate the potential of the InP TS.

A 200 mW InP DHBT W-band power amplifier in transferred-substrate technology with integrated diamond heat spreader

Abstract: A power amplifier in 800 nm transferred-substrate InP DHBT technology is presented in this paper. The technology used in this work features an integrated diamond heat sink layer that has significant impact on the reduction of thermal resistance. This increases the DC-power limit as well as RF output power for the same transistor periphery. The power amplifier delivers 200 mW output power at 87 GHz, for a total emitter periphery of 96 µm, at a peak PAE of 20 % and for more than 25 GHz 3-dB bandwidth.

A 315 GHz reflection-type push-push oscillator in InP-DHBT technology

Abstract: A 315-GHz reflection-type push-push oscillator is presented. It is realized using a 0.8 μm-emitter transferredsubstrate (TS) InP-DHBT technology with an fmax of 320 GHz. The oscillator delivers −10 dBm output power. DC consumption is only 21 mW from a 1.6 volts power supply, which corresponds to 0.5 % overall DC-to-RF efficiency.

An efficient W-band InP DHBT digital power amplifier

Abstract: This paper presents for the first time a high-efficiency W-band power amplifier (PA), the design of which follows the digital PA (DPA) design concept. The PA is realized as MMIC in a 0.8 μm InP DHBT transferred-substrate (TS) process. It utilizes a double-emitter-finger DHBT unit cell with an emitter area of 2 × 0.8 × 6 μm2. In contrast to the usual W-band PAs the single-stage DPA MMIC does not apply any special reactive matching for the transistor, which leads to a very compact chip size of 0.27 mm2. It includes a band-pass filter (BPF) at the output with 0.6 dB insertion loss and 24 dB input return loss at the signal frequency of 95 GHz. Applying an overdriven sinusoidal input signal the DPA achieves a maximum output power of 14.4 dBm and a power-added efficiency (PAE) of 31%. Collector efficiencies of more than 80% demonstrate the great potential of the digital PA concept for future high-speed communications.

Process robustness and reproducibility of sub-mm wave flip-chip interconnect assembly

Abstract: The design margins for sub-mm-wave flip-chip transitions in three different topologies, coplanar-to-coplanar, stripline-to-coplanar, and stripline-to-stripline, were verified with the realization and S-parameter measurement of passive chip assemblies, which contain the same wiring architecture as our InP DHBT circuit integration. High yield was observed, and less than 2 dB insertion loss per transition was measured above 300 GHz on the stripline-to-stripline design.

A 100 GHz fundamental oscillator with 25% efficiency based on transferred-substrate InP-DHBT technology

Abstract: A 96-GHz fixed-frequency fundamental oscillator with high efficiency is presented, realized using a transferred-substrate (TS) 0.8 μm InP-DHBT process. It delivers 9 dBm output power, with phase noise values of −90 dBc/Hz and −118 dBc/Hz at 1 MHz and 10 MHz offset frequency, respectively. DC consumption is only 30 mW from a 1.6 volts power supply, which corresponds to the highest overall DC-to-RF efficiency of a millimeter-wave frequency source reported to date.

Balanced G-band Gm-boosted frequency doublers in transferred substrate InP HBT technology

Abstract: In this paper, balanced G-band Gm-boosted frequency doublers in transferred substrate (TS) InP HBT technology are reported for the first time. The Gm-boosted frequency doublers consist of a phase compensated Marchand balun, Gm-boosted doubler stage, and an optional cascode gain stage at the output. The doubler without cascode demonstrates a maximum output power of +4.7 dBm around a narrow frequency range at 200 GHz when driven with an input power of +10 dBm. A Gm-boosted frequency doubler with cascode demonstrates an output power of +5.4 dBm at 190 GHz when driven with an input power of +11 dBm. The power consumptions of the Gm-boosted frequency doubler without and with cascode are 30.9 mW and 56.4 mW, respectively. The fundamental suppression for both doublers remains better than 17.3 dB over an input frequency range of 75–110 GHz.