Dietmar Kissinger

245-GHz Transmitter Array in SiGe BiCMOS for Gas Spectroscopy

A 245-GHz transmitter (TX) array with an integrated antenna-array for a gas spectroscopy system has been realized. It consists of a push-push VCO with a 1/64 frequency divider, power amplifiers, frequency doublers, and on-chip antennas with localized backside etching. The TX-frequency is tunable in the range from 238 to 252 GHz. The TX-array has been fabricated in a 0.13- μm SiGe:C BiCMOS technology with f T /f max of 300 GHz/500 GHz. Its output power is approximately 7 dBm at 245 GHz, and the effective isotropically radiated power (EIRP) reaches 18 dBm at 245 GHz. The main components of the gas spectroscopy system are a TX and a receiver (RX) in SiGe BiCMOS as well as a gas absorption cell. The sensitivity of this spectroscopy system is demonstrated by measuring the high-resolution absorption spectrum of gaseous methanol ( CH3OH). Due to the increased power provided by the TX-array, the sensitivity of the spectrometer can be increased significantly.

Gas Spectroscopy System for Breath Analysis at mm-wave/THz Using SiGe BiCMOS Circuits

The unique fingerprint spectra of volatile organic compounds for breath analysis and toxic industrial chemicals make an mm-wave (mmW)/THz gas sensor very specific and sensitive. This paper reviews and updates results of our recent work on sensor systems for gas spectroscopy based on integrated transmitter (TX) and receiver (RX), which are developed and fabricated in IHP’s <inline-formula> <tex-math notation=LaTeX>

Sensor system in SiGe BiCMOS at 245 and 500 GHz for gas spectroscopy

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Gas spectroscopy with 245 GHz circuits in SiGe BiCMOS and Frac-N PLL for frequency ramps

</tex-math></inline-formula> SiGe BiCMOS technology. In this paper, we present an mmW/THz spectroscopic system including a folded gas absorption cell of 1.9 m length between the TX and RX modules. We discuss the results and specifications of our sensor system based on integrated TX and RX. We demonstrate TXs and RXs with integrated antennas for spectroscopy at 238–252 GHz and 494–500 GHz using integer-<inline-formula> <tex-math notation=LaTeX>

A 220–275 GHz Direct-Conversion Receiver in 130-nm SiGe:C BiCMOS Technology

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Gas Spectroscopy by Voltage-Frequency Tuning of a 245 GHz SiGe Transmitter and Receiver

</tex-math></inline-formula> phase-locked loops (PLLs). We present a compact system by using fractional-<inline-formula> <tex-math notation=LaTeX>

Gas spectroscopy system with 245 GHz transmitter and receiver in SiGe BiCMOS

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Gas detection with sub-ppm sensitivity based on a 245 GHz SiGe BiCMOS transmitter and receiver

</tex-math></inline-formula> PLLs allowing frequency ramps for the TX and RX, and for TX with superimposed frequency shift keying or reference frequency modulation. In another configuration, the voltage controlled oscillators of the TX and RX local oscillator are tuned directly without PLLs by applying external voltages. Further developments of our system are aimed at realizing an even wider frequency span by switching between frequency bands, and to use a more compact gas absorption cell.

216–256 GHz fully differential frequency multiplier-by-8 chain with 0 dBm output power

This paper reviews our recent work on transmitter (TX) and receiver (RX) circuits in SiGe BiCMOS technology for gas spectroscopy in the frequency ranges around 245 GHz and 500 GHz. The 245 GHz TX consists of a 122 GHz local oscillator (LO) and a frequency doubler, and the 245 GHz RX consists of a low noise amplifier (LNA), a LO, and an active subharmonic mixer. A 245 GHz TX-array increases significantly the sensitivity of the sensor system. The 500 GHz system includes a TX-array, and a subharmonic RX with a transconductance mixer. The 500 GHz TX contains a frequency quadrupler, and the RX uses a frequency doubler for the LO. The LOs of the RX and the TX are controlled by two external phase-locked loops (PLLs). The reference frequency of the TX-PLL is frequency-modulated. The performance of the sensor system is demonstrated by using a gas absorption cell with dielectric lenses between the TX- and RX-modules, and measuring the 2f high-resolution absorption spectrum (second harmonic detection) of gaseous methanol (CH3OH) and acetonitrile (CH3CN).

Gas Sensing around 245 GHz with a SiGe Transmit/Receive System

A compact gas spectroscopy system is presented, which contains a 245 GHz transmitter (TX) and a subharmonic receiver (RX) in SiGe BiCMOS technology, as well as a gas absorption cell. The local oscillators (LOs) of the RX and the TX are controlled by two external Fractional-N phase-locked loops (Frac-N PLLs) allowing fast frequency ramps with superimposed frequency shift keying (FSK) or analog frequency modulation. The sensitivity of this spectroscopic system is evaluated by measuring the high-resolution absorption spectrum of gaseous methanol (CH3OH). Spectra of CH3OH with a high signal-to-noise ratio (SNR) are shown for the range 241–242 GHz.