Hans Gustat

60 GHz transceiver circuits in SiGe:C BiCMOS technology

This paper presents the design and measurement of key circuit building blocks for a high-data-rate transceiver in the 60 GHz band. The adopted modulation scheme is ASK, for a simple configuration with high data rate. The circuits presented are: LNA, oscillator, mixer, modulator and demodulator. The circuits are fabricated in a 0.25 /spl mu/m SiGe:C BiCMOS technology.

An 8-bit, 12 GSample/sec SiGe track-and-hold amplifier

We present the design and implementation of an ultra-high-speed SiGe BiCMOS track-and-hold amplifier (THA) for use in high-speed analog-to-digital converters. The use of a degeneration inductor in the input buffer significantly improves the performance of the THA. The THA was fabricated in a commercially-available 0.25 /spl mu/m 200 GHz SiGe HBT BiCMOS process technology. The circuit occupies an area of 1.2 mm/sup 2/, and exhibits -49.5 dBc of total harmonic distortion (THD) when operated at a sampling frequency of 12.5 GHz with an input frequency of 3.0 GHz. Operating from a 3.5 V supply, the total power consumption is 0.7 W. To our knowledge, this circuit is the fastest 8-bit Si-based THA achieved to date.

A Low-Power,

A low-power, X-band low-noise amplifier (LNA) is presented. Implemented with 180 GHz silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs), the circuit occupies 780times660 mum2. The LNA exhibits a gain of 11.0 dB at 9.5 GHz, a mean noise figure of 2.78 dB across X-band, and an input third-order intercept point of -9.1 dBm near 9.5 GHz, while dissipating only 2.5 mW. The low-power performance of this LNA, together with its natural total-dose radiation immunity, demonstrates the potential of SiGe HBT technology for near-space radar applications

X

This paper presents a low-power high-speed BiCMOS track-and-hold amplifier (THA). It combines the differential switched-emitter follower of (Vorenkamp and Verdaasdonk, 1992) with the low-droop output buffer presented in (Fiocchi et al., 2000). A test implementation consumes 70 mW of total power (30 mW THA). It works up to 15 GS/s, using minimum-size HBTs in a 0.25/spl mu/m 200 GHz SiGe BiCMOS technology. At 10 GS/s and an input signal of 1 GHz, the achieved THD corresponds to 6.8 bits accuracy. To our knowledge, the present circuit is by far the fastest THA with low power consumption and high accuracy.

-Band SiGe HBT Low-Noise Amplifier for Near-Space Radar Applications

We investigate the effects of both X-ray and proton irradiation on a novel 200 GHz/90 GHz (npn/pnp) complementary SiGe:C HBT technology. The DC forward mode total dose tolerance of the pnp HBTs is shown to exceed that of the npn HBTs by a significant margin after being subjected to both 63-MeV proton and 10-keV X-ray sources, while the AC characteristics of both devices exhibit no degradation up to X-ray doses as high as 1.8 Mrad(SiO2). Pre- and post-irradiation results from a current feedback operational amplifier implemented in this technology and irradiated up to a dose of 1.8 Mrad(SiO2) are presented, showing no degradation in performance metrics under two low current density bias configurations.

A low-power, 10GS/s track-and-hold amplifier in SiGe BiCMOS technology

We investigate a novel implementation of junction isolation to harden a 200 GHz SiGe:C HBT technology without deep trench isolation against single event effects. The inclusion of isolation is shown to have no effect on the dc or ac performance of the nominal device, and likewise does not reduce the HBTs inherent tolerance to TID radiation exposure on the order of a Mrad. A 69% reduction in total integrated charge collection across a slice through the center of the device was achieved. In addition, a 26% reduction in collected charge is reported for strikes to the center of the emitter. 3-D NanoTCAD simulations are performed on RHBD and control device models yielding a good match to measured results for strikes from the emitter center to 8 ¿m away. This result represents one of the most effective transistor layout-level RHBD approaches demonstrated to date in SiGe.

The Effects of X-Ray and Proton Irradiation on a 200 GHz/90 GHz Complementary

This paper presents a monolithic master-slave comparator in an ECL configuration with series-gating for ultra-high-speed medium-resolution analog-to-digital conversion. Implemented in a 200 GHz SiGe HBT technology, the complete chip die, including bondpads, is 1.731 /spl times/ 1.141 mm/sup 2/, with the comparator occupying only 0.0226 mm/sup 2/ when integrated as part of an ADC. It dissipates a total of 405 mW from a 3.5 V power supply. Operating with an input frequency of 5 GHz, the circuit can oversample up to 32 GS/s, with input sensitivity ranging from 5 mV/sub pp/ at 15 GS/s to 37 mV/sub pp/ at 32 GS/s. Operating at Nyquist, the comparator can sample up to 30 GS/s, with input sensitivity ranging from 12 mV/sub pp/ at 20 GS/s to 30 mV/sub pp/ at 30 GS/s. To our knowledge, this comparator achieves the best input sensitivity-sampling rate combination when compared with other standalone comparators in literature.

(npn + pnp)

This paper presents a high-speed 4 bits full-flash Analog-to-Digital Converter for an UWB radar applications, implemented in 190 GHz SiGe BiCMOS technology. The ADC occupies 1.5 × 1.5 mm2, including bondpads. Converter has 6 GHz input bandwidth and operates up to 15 GSample/s. Power dissipation is 1 W including test buffers and 600 mW for a core part itself.

SiGe:C HBT Technology

We present the first demonstration of a continuous-time, fifth-order, elliptic, gm-C low-pass active filter in 0.25 mum complementary (npn + pnp) silicon-germanium (C-SiGe) heterojunction bipolar transistor (HBT) technology. This C-SiGe technology features npn SiGe HBTs with peak fT and fmax of 170 GHz and 170 GHz, respectively, as well as pnp SiGe HBTs having fT and fmax of 90 GHz and 120 GHz, respectively. This C-SiGe active filter was implemented with Voorman transconductors (Voorman, 2000) to fully exploit the complementary high-speed npn and pnp SiGe HBTs. The circuit occupies an area of 0.82 mm2, and exhibits a filter cut-off frequency of 4.1 GHz. This C-SiGe active filter achieves a record continuous tuning range between 70 MHz and 4.1 GHz, attains an output noise power spectrum density (PSD) of -143 dBm/Hz, and operates off a 3.5 V supply, with a total power consumption of 100 mW at the maximum bandwidth of 4.1 GHz

Junction Isolation Single Event Radiation Hardening of a 200 GHz SiGe:C HBT Technology Without Deep Trench Isolation

A comparison of cross-coupled oscillator performance is presented for a high-speed, complementary SiGe (C-SiGe = npn + pnp) BiCMOS platform with matched npn and pnp performance. Results show with all factors held constant, the pnp-only VCO design holds an advantage in white FM phase noise over its npn counterpart at constant current; a counter-intuitive outcome if one only considers absolute base resistance. The reduced noise in the pnp-only VCO is shown to stem from the devices decreased β compared to the npn, which reduces conversion of the thermal noise associated with the base resistance to the output node. Understanding this phase noise reduction effect has potential to influence oscillator device selection in any given technology family.