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The implementation of backhauling links poses several challenges to the designers which are requested to limit the hardware costs in the framework of complex millimeter wave radio systems. This work presents a monolithically integrated E-band I/Q receiver covering the whole bandwidth from 71 to 86 GHz. The chip was implemented in a 55 nm SiGe BiCMOS technology which allows reaching a high level of integration. The receiver is based on a Low Noise Amplifier (LNA) stage and a Variable-Gain Amplifier (VGA) which provide a −11 dBm IP1dB. A double balanced mixer provides I/Q baseband outputs through a reduced-size differential phase shifter which allows to contain the chip size to 1.8 mm2. [ABSTRACT FROM AUTHOR]

Maximum oscillation frequency (${f}_{\textit {MAX}}$) of mm-wave transistors is one of the key figures of merit (FOMs) for evaluating the HF-performance of a given technology. However, accurate measurements of ${f}_{\textit {MAX}}$ are very difficult. Determination of ${f}_{\textit {MAX}}$ is significantly affected by the measurement uncertainties in the admittance (${y}$) parameters. In order to get rid of the random measurement error and to obtain a reliable and stable ${f}_{\textit {MAX}}$ value, the frequency dependent ${y}$ -parameters are described by rational functions formulated from the small-signal hybrid ${\pi }$ -model of the transistor under investigation. The parameters of these functions are determined following a least square error technique that minimizes the functional error with the measured data. The approach is especially useful for a fast and reliable evaluation of ${f}_{\textit {MAX}}$ value. Devices from two different SiGe and an FDSOI (Fully Depleted Silicon On Insulator) MOS technology are measured and stable ${f}_{\textit {MAX}}$ values are estimated following this approach. [ABSTRACT FROM AUTHOR]

A 240-GHz direct conversion I–Q receiver with 74-GHz RF bandwidth is reported. It features a mixer-first architecture with fundamental local oscillator (LO)-frequency Gilbert-cell downconversion mixers, variable-gain baseband amplifiers, and a 240-GHz LO source, making it the first fully integrated 240-GHz I–Q receiver. With a phase noise of −82 dBc/Hz at 1-MHz offset, the LO source has a 27-GHz tuning range and consists of a 120-GHz voltage-controlled oscillator (VCO), a frequency doubler, and a static divide-by-128 chain. The measured peak downconversion gain is 23 dB and is adjustable over 38 dB. Along with the IF bandwidth of 59 GHz, the wide RF bandwidth makes it suitable for both high data-rate communication and emerging quantum computing applications. The chip occupies an area of 1.837 mm2 and consumes 859 mW. [ABSTRACT FROM AUTHOR]

The system and transistor-level design of low-power millimeter wave (mm-wave) active tags in silicon is discussed in detail. Two active mm-wave tags with identical system architecture, padframe, and chip size were designed and fabricated in 55-nm SiGe BiCMOS and 45-nm SOI CMOS technologies, respectively. They feature a three-stage low-noise amplifier (LNA), a wake-up detector, a BPSK modulator, and two variable gain output stages, each driving a separate transmit antenna in antiphase. The wake-up detector can be used to switch OFF all the blocks except for the LNA and detector, thus further reducing power consumption. The measured performance of the SiGe and SOI chips is remarkably similar: 19- and 20-dB gain, 9- and 8-dB noise figure, and 25-/10.8-mW (active/idle) and 18-mW power consumption, respectively. The SiGe tag was flip-chip-mounted on a mini-PCB with one receive and two transmit antennas for system level functionality tests carried out over a distance of 5 m. The SiGe-tag wake-up sensitivity was verified to be −62 dBm, in excellent agreement with simulation results. [ABSTRACT FROM PUBLISHER]

This paper presents Si/SiGe:C and InP/GaAsSb HBTs which feature specific assets to address submillimeter-wave and THz applications. Process and modeling status and challenges are reviewed. The specific topics of thermal and substrate effects, reliability, and HF measurements are also discussed. [ABSTRACT FROM PUBLISHER]

A 234–261-GHz signal source with record 7.2-dBm output power at 240 GHz and −105 dBc/Hz phase noise at 10-MHz offset is reported. Fabricated in a production 55-nm SiGe BiCMOS process with HBT f\mathrm {T}/f\mathrm {MAX} of 330/350 GHz, the circuit includes a 120-GHz fundamental frequency VCO with 1.2-V AMOS varactors, a broadband MOS-HBT cascode LO tree driving a divide-by-128 chain, and a doubler with a record drain efficiency of 11.9%. The total power consumption of the signal source is 386 mW resulting in a DC-to-RF efficiency of 1.3%. A detailed discussion of the candidate LO-tree and doubler topologies and of the design methodology, which capitalizes on the MOS-HBT cascode and unique features of the 55-nm SiGe BiCMOS process, is provided. [ABSTRACT FROM AUTHOR]

Power amplifier (PA) design for 160-GHz applications in an advanced SiGe heterojunction bipolar transistor (HBT) technology with saturated output power (Psat) in excess of 10 dBm is presented. The architecture is based on a three-stage pseudodifferential configuration that was implemented in SiGe HBT evaluation technology with f\max of 400 GHz. At saturation, a PA breakout circuit delivers 10 dBm with 20-dB gain. From 150 to 170 GHz, the small-signal gain is within 20–32 dB and the output referred 1-dB compression point (P1\ dB) is 8.5 dBm at 160 GHz. High output power was possible due to optimum device sizing, efficient layout, and accurate EM modeling. To our best knowledge, this is the highest output power reported for silicon PAs operating beyond 120 GHz. [ABSTRACT FROM AUTHOR]

This paper describes a methodology for extracting and verifying the high-frequency model parameters of the HICUM L0 and L2 models of a silicon–germanium HBT from device and circuit measurements in the 110–325-GHz range. For the first time, the non-quasi-static effects, missing in the HICUM/L0 model, are found to be essential in accurately capturing the frequency dependence of the transistor maximum available power gain beyond the inflection frequency for unconditional stability. Furthermore, it is demonstrated that the optimal partitioning of the area and periphery components of the junction base–emitter, base–collector, and collector–substrate capacitances, and of the internal and external base and collector resistances can only be determined from S-parameter measurements beyond 200 GHz. The extracted models are validated on state-of-the-art linear and nonlinear circuits (amplifier, voltage-controlled oscillator (VCO), and VCO + divider chain) operating at frequencies as high as 240 GHz. [ABSTRACT FROM AUTHOR]

A D-band SiGe HBT total power radiometer is reported with a peak responsivity of 28 MV/W, a noise equivalent power (NEP) of 14–18 \fW/Hz^1/2, and a temperature resolution better than 0.35 K for an integration time of 3.125 ms. The 1/f noise corner of the radiometer is lower than 200 Hz. Fabricated in a developmental technology with 270-GHz fT and 330-GHz fMAX, it includes a five-stage low-noise amplifier (LNA) with 4–7-GHz bandwidth and over 35 dB of gain centered at 165 GHz, along with a square-law detector with an NEP below 6 \pW/Hz^1/2 up to 170 GHz. An average system noise temperature of 1645 K is obtained using the Y-factor method and a noise bandwidth of 10 GHz calculated from the measured S21(f) characteristics of the radiometer. The reduced 1/f noise corner frequency in the presence of the amplifier, compared to that of the detector, appears to indicate that, unlike in III–V radiometers, LNA gain fluctuations are not a problem in SiGe HBT radiometers. The circuit consumes 95 mW and occupies \ 765\,\times\ 490∼\mu\ m^2. Wafer mapping of the radiometer sensitivity and of the amplifier gain was performed across different process splits. The mapping results demonstrate that the radiometer can be employed as a relatively simple and area-efficient transistor noise-measure monitor, useful in SiGe HBT vertical profile optimization. [ABSTRACT FROM AUTHOR]

The overall purpose of this paper (including Part I, in this issue) is the prediction of the ultimate electrical high-frequency performance potential for SiGeC heterojunction bipolar transistors under the constraints of practical applications. This goal is achieved by utilizing most advanced device simulation tools with parameters calibrated to existing experimental results. This Part I outlines the overall scaling procedure and then focuses on the vertically scaled structure. According to isothermal device simulation, the “ultimate” doping profile yields a peak transit frequency fT of almost 1.5 THz, a \BVCEO above 1 V (dependent on BE bias) and a zero-bias internal base sheet resistance of about 3 \k\Omega/\sq. The reasons for achieving a higher product fT \BV \rm CEO ( > \1.5\ \THzV) than anticipated from the classical Johnson limit are explained. Finally, it is found that fT is limited by the minority charge stored in the BE junction and that \BVCEO is mainly determined by the tunneling mechanisms in the base–collector space-charge region. [ABSTRACT FROM PUBLISHER]

Noise parameter (F\min, Zopt, and R n) measurements of SiGe HBTs are provided for the first time in the 70–170-GHz range. In the W-band, this is accomplished by integrating on a single chip a source impedance tuner with the device-under-test and a low-noise amplifier with 3.8-dB noise figure. Noise-figure measurements were performed over multiple source impedances using a commercial single-sideband downconverter. In the D-band, where off-chip setup losses are overwhelming, the source impedance tuner, the transistor under test, and the entire receiver with a noise figure of 10 dB were integrated on a single silicon die, and direct noise-figure measurements were conducted first on the test setup with the transistor under test, and next on the reference receiver without the test transistor. Both analog and digital source impedance tuners, based on n-MOSFET variable resistors, n-MOSFET switches, and accumulation-mode varactors, have been designed and characterized. Finally, the existing technique to extract the SiGe HBT noise parameters from Y-parameter measurements, without any noise-figure measurements, is refined to include noise correlation and is validated up to 170 GHz. The measured source–pull and Y-parameters results show that the minimum noise figure of state-of-the-art SiGe HBTs remains below 5 dB throughout the D-band. [ABSTRACT FROM AUTHOR]

SiGe HBT noise parameters (NF\min, Rn and \Gammaopt) are for the first time extracted in the entire 130 – 170 GHz frequency range. This achievement is realized using a D-band on-chip source-pull system, which includes an impedance tuner integrated with the transistor under test. On-wafer noise power measurements on this system were performed for each tuner impedance state, from which are extracted the transistor noise parameters in the complete D-band. [ABSTRACT FROM PUBLISHER]

In this letter, we report a record gate delay of 1.65 ps of a current-mode logic ring oscillator (RO) fabricated with an advanced SiGe:C heterojunction bipolar transistor technology. Outstanding performance has been achieved through process and layout optimization and inductive peaking in series with the load resistor. The RO operates at a single-ended voltage swing of 200 mV. The transistors used in the RO exhibit a peak transit frequency fT of 310 GHz and a peak maximum oscillation frequency f\max of 400 GHz. To the best of our knowledge, a gate delay of 1.65 ps is the fastest result for a bipolar transistor-based technology. [ABSTRACT FROM AUTHOR]

In this letter, we report load pull measurements on SiGe HBTs at 94 GHz. Nowadays, this kind of device exhibits FMAX above 400 GHz and thus has a growing interest for W-band applications. A load pull test bench is developed for the characterization of this device with special care on architecture and calibration procedure for accurate measurements in 75–110 GHz. The device was characterized under large signal operation showing attractive performance for power amplifier design. A state-of-the-art power density of 18.5 \mW/\mu\m^2 at 1-dB compression has been obtained at 94 GHz. [ABSTRACT FROM PUBLISHER]