Stefan Malz

A Fully Integrated 240-GHz Direct-Conversion Quadrature Transmitter and Receiver Chipset in SiGe Technology

This paper presents a fully integrated direct-conversion quadrature transmitter and receiver chipset at 240 GHz. It is implemented in a 0.13-μm SiGe bipolar-CMOS technology. A wideband frequency multiplier (×16) based local-oscillator (LO) signal source and a wideband on-chip antenna designed to be used with an external replaceable silicon lens makes this chipset suited for applications requiring fixed and tunable LO. The chipset is packaged in a low-cost FR4 printed circuit board resulting in a complete solution with compact form-factor. At 236 GHz, the effective-isotropic-radiated-power is 21.86 dBm and the minimum single-sideband noise figure is 15 dB. The usable RF bandwidth for this chipset is 65 GHz and the 6-dB bandwidth is 17 GHz. At the system level, we demonstrate a high data-rate communication system where an external modem is operated in its two IF-bandwidth modes (250 MHz and 1 GHz). For the quadrature phase-shift keying modulation scheme, the measured data rate is 2.73 Gb/s (modem 1-GHz IF) with bit-error rate of 10-9 for a 15-cm link. The estimated data rate over the 17-GHz RF bandwidth is, hence, 23.025 Gb/s. Also, higher order modulation schemes like 16 quadrature amplitude modulation (QAM) with a data rate of 0.677 Gb/s and 64-QAM with a data rate of 1.0154 Gb/s (modem 250-MHz IF) is demonstrated. A second application demonstrator is presented where the wide tunable RF bandwidth of the chipset is used for material characterization. It is used to characterize an FR4 material (DE104) over the 215-260-GHz range.

A 240-GHz circularly polarized FMCW radar based on a SiGe transceiver with a lens-coupled on-chip antenna

A 240-GHz monostatic circular polarized SiGe frequency-modulated continuous wave radar system based on a transceiver chip with a single on-chip antenna is presented. The radar transceiver front-end is implemented in a low-cost 0.13 µm SiGe HBT technology version with cut-off frequencies f T /f max of 300/450 GHz. The transmit block comprises a wideband ×16 frequency multiplier chain, a three-stage PA, while the receive block consists of a low-noise amplifier, a fundamental quadrature down-conversion mixer, and a three-stage PA to drive the mixer. A differential branch-line coupler and a differential dual-polarized on-chip antenna are added on-chip to realize a fully integrated radar transceiver. All building blocks are implemented fully differential. The use of a single antenna in the circular polarized radar transceiver leads to compact size and high sensitivity. The measured peak-radiated power from the Si-lens equipped radar module is +11 dBm (equivalent isotropically radiated power) at 246 GHz and noise figure is 21 dB. The characterization bandwidth of the radar transceiver is 60 GHz around the center frequency of 240 GHz, and the simulated Tx-to-Rx leakage is below −20 dB from 230 to 260 GHz. After system calibration the resolution of the system to distinguish between two targets at different distance of 3.65 mm is achieved, which is only 21% above the theoretical limit.

Active Multiple Feed On-Chip Antennas with Efficient In-Antenna Power Combining Operating at 200-320 GHz

The design and measurement of active multiple-feed on-chip antennas realized in a SiGe seven metal layer backend process are presented for millimeter-wave applications. To prevent the excitation of surface waves, the principle of an integrated lens antenna (ILA) is used. In-antenna power-combining is realized by using a novel concept in which the outputs of two or more parallel differential amplifiers are directly combined in the radiating element itself. The proof-of-concept is shown by characterizing the antennas directly without the amplifiers being connected and by using adequate feeding networks capable of demonstrating high ILA bandwidths. Further, the power-splitting is realized through distributed transformer circuits, which offer high bandwidths at low losses. Different antennas are evaluated in order to attain reflection coefficients better than −10 dB over the entire frequency band of 200–320 GHz. Finally, the power-combining capabilities of such antennas are demonstrated by connecting a four-feed differential antenna to four single stage cascode amplifiers in parallel.

J-band amplifier design using gain-enhanced cascodes in 0.13 μm SiGe

This paper presents two J-band amplifiers in different 0.13 μm SiGe technologies: a small signal amplifier (SSA) in a technology in which never before gain has been shown over 200 GHz; and a low noise amplifier (LNA) design for 230 GHz applications in an advanced SiGe HBT technology with higher fT/fmax, demonstrating the combination of high gain, low noise, and low power in a single amplifier. Both circuits consist of a four-stage pseudo-differential cascode topology. By employing series–series feedback at the single-stage level the small-signal gain is increased, enabling circuit operation at high-frequencies and with improved efficiency, while maintaining unconditional stability. The SSA was fabricated in a SiGe BiCMOS technology by Infineon with fT/fmax values of 250/360 GHz. It has measured 19.5 dB gain at 212 GHz with a 3 dB bandwidth of 21 GHz. It draws 65 mA from a 3.3 V supply. On the other hand, a LNA was designed in a SiGe BiCMOS technology by IHP with f T /f max of 300/450 GHz. The LNA has measured 22.5 dB gain at 233 GHz with a 3 dB bandwidth of 10 GHz and a simulated noise figure of 12.5 dB. The LNA draws only 17 mA from a 4 V supply. The design methodology, which led to these record results, is described in detail with the LNA as an example.

A lens-integrated 430 GHz SiGe HBT source with up to −6.3 dBm radiated power

This paper presents a 430 GHz source implemented in a 0.13-µm SiGe BiCMOS technology with fT/fmax of 300 GHz/450 GHz. The source comprises a fundamental differential Colpitts cascode oscillator at 215 GHz driving a balanced common-collector doubler that utilizes inductive 2nd-harmonic feedback at the emitter output in order to boost the generated 2nd-harmonic current. The doubler is co-designed with a lens-coupled on-chip circular slot antenna providing the appropriate input impedance to the doubler output. In combination with a 3-mm diameter silicon-lens, the total peak radiated power is −6.3 dBm at a power dissipation of 165 mW. To the authors knowledge, the presented source shows the highest reported power for any silicon-based single-element radiator beyond 350 GHz.

30 Gbps wireless data transmission with fully integrated 240 GHz silicon based transmitter

In this paper we present communication measurements with a fully integrated 240 GHz transmitter based on a single SiGe RF chip in 0.13µm Bi-CMOS technology. For an improved transmitter gain the on-chip antenna is built up using in-antenna power combining in conjunction with a dielectric 12mm silicon lens. The measurement results show that data rates of up to 30 Gbps are possible for 8-PSK modulated signals. For more robust communication with bit error ratio below 10−3, data rates of 24 Gbps could be achieved using QPSK modulated signals, without any error correction.

Real100G.RF: A Fully Packaged 240 GHz Transmitter with In-Antenna Power Combining in 0.13 μm SiGe Technology

Abstract This paper reports on the research activities during the first phase of the project Real100G.RF, which is part of the German Research Foundation (DFG) priority programm SPP1655. The project’s main objective is to research silicon-based wireless communication above 200 GHz to enable data rates in excess of 100 gigabit per second (Gbps). To that end, this paper presents a fully packaged 240 GHz RF transmitter front-end with power combining antenna in 0.13 μ

SiGe Transmitter and Receiver Circuits for Emerging Terahertz Applications

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A 240 GHz circular polarized FMCW radar based on a SiGe transceiver with a lens-integrated on-chip antenna

m SiGe technology. The design of circuit building blocks, passives, antenna and high-speed packaging is discussed. Communication measurements show data rates of 8 Gbps with an EVM of 12.4% using 16-QAM, 24 Gbps with 26.5% EVM using QPSK and 30 Gbps with 27.9% EVM using 8-PSK.

A 233-GHz low noise amplifier with 22.5dB gain in 0.13μm SiGe

This paper presents recent developments on transmitter and receiver circuit in advanced SiGe technologies for emerging applications in the sub-millimeter wave region of the electromagnetic spectrum. This includes high-power harmonic oscillators, multiplier chains, and heterodyne I/Q transmitters for terahertz signal generation, as well as direct detectors, heterodyne receivers and Radar transceivers for wide-band signal detection. The circuits are attached to a secondary silicon lens and packaged on low-cost FR4 printed circuit boards.