Christoph Scheytt

A low-cost miniature 120GHz SiP FMCW/CW radar sensor with software linearization

This paper presents an integrated mixed-signal 120GHz FMCW/CW radar chipset in a 0.13μm SiGe BiCMOS technology. It features on-chip MMW built-in-self-test (BIST) circuits, a harmonic transceiver, software linearization (SWL) circuits and a digital interface. This chipset has been tested in a low-cost package, where the antennas are integrated. Above 100GHz, our transceiver has achieved state-ofthe-art integration level and receiver linearity, and DC power consumption.

60-Ghz OFDM Systems for Multi-Gigabit Wireless LAN Applications

This paper presents the developed 60-GHz OFDM hardware demonstrators and the newly designed 60-GHz system architecture targeting for multi-gigabit wireless LAN applications. The hardware demonstrators developed so far are made up of maximum 1-Gbps OFDM baseband realized on FPGA platform and 60-GHz super-heterodyne transceivers fabricated by SiGe BieMOS technologies. Wireless transmission in 60-GHz links is successfully demonstrated in indoor office environments. The next generation 60-GHz OFDM systems are designed to provide data rate higher than 3-Gbps utilizing the channel bandwidth of 2.16-GHz. Advanced channel coding schemes including low-density-parity-check (LDPC) coding are applied to have higher coding gain. RF transceivers are based on sliding IF architecture and designed to be compatible to the channel plans defined in the 60-GHz standards.

Integrated Adjustable Phase Shifters

When examining a monthly bank account statement, it is not only the number below the bottom line that matters. Whether that number has a minus or plus in front of it is crucial. For many technical problems, the sign matters as well. In circuits, we can change the sign by means of phase shifters. Moreover, by using phase shifters, intermediate states between the signs (including complex values) can be set in circuits. Hence, phase shifters play an important role in electrical engineering. Unfortunately, this article does not give direct insights to change the sign of your bank statement. However, it aims to give a comprehensive overview of tunable phase shifters for radio frequency (RF) applications including cookbooklike design guidelines and performance comparisons. The focus of this article is put on phase shifters fully integrated in a chip.

A low-phase-noise 61 GHz push-push VCO with divider chain and buffer in SiGe BiCMOS for 122 GHz ISM applications

This paper presents a 61 GHz push-push VCO with an integrated divide-by-eight divider and an output buffer in a 130 nm SiGe BiCMOS process. The VCO core features a differential Colpitts topology with coupled inductors to improve phase noise performance. Eight sub-bands are realized by three digital tuned varicaps, which are placed in parallel with the analog tuned varicap. Its tuning range is 60.85-63.65 GHz with a measured output power of above 10 dBm. The measured phase noise is -106 dBc/Hz at 1 MHz offset with an overall VCO/buffer power dissipation of 93.6 mW. The VCO/buffer has achieved an efficiency of 14%, a figure-of-merit including output power (FOMP) of 193.1 dBc/Hz and an ITRS FOM of 185.6 dBc/Hz.

A 122 GHz Multiprobe Reflectometer for Dielectric Sensor Readout in SiGe BiCMOS Technology

In this publication a fully integrated multiprobe reflectometer at 122 GHz is presented. It can be used for readout of resonator-based dielectric sensors for measurement of chemical, biological, or medical liquids. The circuit consists of a voltage-controlled oscillator, an amplitude modulator, a capacitive tapped line, four power detectors, and a dummy sensor. The circuit is operated from a 3.75-V supply and has a power consumption of 319 mW. The readout principle of the circuit is demonstrated by comparing the S-parameters of the dummy sensor to measurements with a commercially available vector network analyzer. The circuit has been fabricated in a 190-GHz SiGe:C BiCMOS technology and occupies an area of 0.54 mm² .

A 122 GHz receiver in SiGe technology

A 122 GHz subharmonic receiver for imaging and sensing applications has been realized, which consists of a single-ended LNA, a push-push VCO with 1/32 divider, a polyphase filter, and a subharmonic mixer. It is fabricated in SiGe:C BiCMOS technology with fT/fmax of 255GHz/315GHz. The down-conversion gain of the receiver is 25 dB at 127 GHz, and the corresponding noise figure is 11 dB. The 3-dB bandwidth reaches from 125 GHz to 129 GHz. The input 1-dB compression point is at −40 dBm. The receiver consumes 139 mA at a supply voltage of 3.3 V.

A switching-mode amplifier for class-S transmitters for clock frequencies up to 7.5 GHz in 0.25µm SiGe-BiCMOS

This paper presents the first voltage mode H-bridge switching amplifier in a fast complementary SiGe-technology for frequencies in the GHz range. The amplifier is suited as a driver for a high power GaN amplifier in class-S transmitters. It can be operated with pseudo-random digital pulse trains up to 7.5 Gbit/s. The measured broadband output power for a rectangular drive signal with a 50% duty cycle and a frequency of 2 GHz is about 148 mW. The efficiency of the switching stage including its two-stage inverter driver is about 43%. Including the input current-mode-logic (CML) stage, the PAE is about 30%.

94 GHz Amplifier in SiGe Technology

A 94 GHz amplifier fabricated in 0.25 mum SiGe BiCMOS technology and using a novel transmission line structure is presented. The circuit is a two-stage cascode topology utilizing transmission lines for input, output and inter-stage matching. The amplifier is designed for high gain, minimum noise figure and low power consumption. Measurements show a gain of 16.2 dB and a noise figure of 10.6 dB at 94 GHz. The power consumption is 61 mW from a 3.5 Volt supply. The design-style with top-plate ground used in this amplifier is a good candidate for IC-designs at even higher frequencies in silicon-based technologies.

A 13.5-to-17 dBm P1dB, selective, high-gain power amplifier for 60 GHz applications in SiGe

A fully integrated differential power amplifier (PA), produced in 0.25 mum SiGe:C BiCMOS process for 60 GHz application is presented. Differential 1 dB compression point (P1dB) at the output is 13.5 dBm at 61.5 GHz and as high as 17 dBm at 65 GHz. Saturated power is 18.7 dBm at 61.5 GHz and maximum 19 dBm at 66 GHz. PA features three-stage cascade topology with measured gain of 33 dB at 61 GHz. The amplifier is selective with 20 dB image rejection at 51 GHz, which is image frequency for the targeted transmitter architecture. Compact differential design resulted in small size of 0.6 mm2 with pads. Maximum power-aided efficiency (PAE) is 7.8% for 800 mW power consumption, and 10.2% for 600 mW.

An integrated 125GHz Sensor with read-out circuit for permittivity measurement of liquids

In this publication an integrated dielectric sensor with read-out circuit in SiGe BiCMOS technology at 125GHz is presented. The sensor consist of a 500 µm shorted half-wave coplanar waveguide transmission line in the top metal layer. Read-out of the sensor is performed by measurement of its reflection coefficient with an integrated multiprobe reflectometer and signal source. The MMIC has been fabricated in a 190-GHz fT SiGe:C BiCMOS technology and assembled on a printed circuit board. Functionality of the sensor is demonstrated with a stimulus frequency from 118 to 133GHz with immersion of the sensor into a binary methanol-ethanol mixture.