Herbert Knapp

SiGe bipolar technology for automotive radar applications

A SiGe bipolar technology for automotive radar applications around 77 GHz has been developed. A cut-off frequency of 200 GHz, a maximum oscillation frequency of 275 GHz, and a gate delay of 3.5 ps have been obtained. First key building blocks for 77 GHz systems like VCOs and mixers have been realized with this technology.

A 77GHz 4-channel automotive radar transceiver in SiGe

A fully integrated 4-channel automotive radar transceiver chip, integrated in a 200-GHz SiGe:C production technology, is presented. With a typical transmit power of 2 x +7 dBm at the antenna ports and all functions active, the chip draws a current of about 600 mA from a single 5.5 V supply. The design permits FMCW operation in the 76 to 77 GHz band at chip-backside temperatures from -40degC to +125degC.

Lumped and distributed lattice-type LC-baluns

This paper presents two balun circuits derived from the lumped Lattice-type LC-balun. First the lumped LC-balun bridge elements are substituted by microstrip lines. This results in an improved performance at the 2nd and 3rd harmonic frequency for RF power amplifier output baluns. Secondly, the lumped Lattice-type LC-balun is extended to a dual band balun. Independent impedance transformation and balun conversion can be done at two different frequencies. The design equations are derived.

40-Gb/s 2:1 multiplexer and 1:2 demultiplexer in 120-nm standard CMOS

We present an integrated 2:1 multiplexer and a companion 1:2 demultiplexer in CMOS. Both integrated circuits (ICs) operate up to a bit rate of 40 Gb/s. The 2:1 multiplexer features two in-phase data inputs which are achieved by a master-slave flip-flop and a master-slave-master flip-flop. Current-mode logic is used because of the higher speed compared to static CMOS and the robustness against common-mode disturbances. The multiplexer uses no output buffer and directly drives the 50-/spl Omega/ environment. An inductance connected in series to the output in combination with shunt peaking is used to enhance the bandwidth of the multiplexer. Fully symmetric on-chip inductors are used for peaking. The inductors are mutually coupled to save chip area. Lumped equivalent models of both peaking inductors allow optimization of the circuit. The ICs are fabricated in a 120-nm standard CMOS technology and use 1.5-V supply voltage. Measured eye diagrams of both ICs demonstrate their performance.

42 GHz static frequency divider in a Si/SiGe bipolar technology

Frequency dividers are key components for multi-gigabit-per-second optical fiber links. For this application, maximum speed is mandatory, while the power consumption is not a limiting factor. To date, the highest operating speed for static frequency dividers has been achieved with III-V devices. For AlInAs/GaInAs HBTs with 130 GHz f/sub T/, 39.5 GHz operation is measured, and for 0.1 /spl mu/m InAlAs/InGaAs HEMTs with f/sub T/ of approximately 200 GHz an operating speed of 40.4 GHz is recently reported. The fastest published static silicon divider operates up to 35 GHz. Silicon bipolar technologies offer high reliability and cost-effectiveness. This divider is fabricated in a 0.5 /spl mu/m double-polysilicon self-aligned Si/SiGe heterojunction bipolar technology.

86 GHz static and 110 GHz dynamic frequency dividers in SiGe bipolar technology

We present static and dynamic frequency dividers manufactured in a 200 GHz f/sub T/ SiGe bipolar technology. The static divider has a divide ratio of 32 and operates up to 86.2 GHz. The dynamic divider is based on regenerative frequency division and has a divide ratio of two. It operates up to 110 GHz (limited by the measurement equipment). The power consumption of the static and dynamic frequency dividers is 900 mW and 310 mW, respectively.

Integrated Bandpass Filter at 77 GHz in SiGe Technology

The implementation and characterization of an integrated passive bandpass filter at 77GHz is presented. A lumped elements filter occupying very small die area (110times60mum2, without pads) is demonstrated. It is realized with spiral inductors and metal-insulator-metal capacitors. The filter is fabricated in an advanced SiGe:C technology. It has a center frequency of 77.3GHz and a bandwidth of 12GHz. The insertion loss is 6.4dB. This is the first time that integrated inductors are used for filters at millimeter wave frequencies around 80GHz

An 84 GHz Bandwidth and 20 dB Gain Broadband Amplifier in SiGe Bipolar Technology

This paper reports on the design, fabrication, and characterization of a lumped broadband amplifier in SiGe bipolar technology. The measured differential gain is 20 dB with a 3-dB bandwidth of more than 84 GHz, which is the highest bandwidth reported so far for broadband SiGe bipolar amplifiers. The resulting gain bandwidth product (GBW) is more than 840 GHz. The amplifier consumes a power of 990 mW at a supply of -5.5 V.

Sub 5 ps SiGe bipolar technology

A SiGe bipolar technology for mixed digital and analog RF applications is presented. Balanced device performance is achieved with a transit frequency f/sub T/ of 155 GHz at a collector emitter breakdown voltage BV/sub CEO/ of 1.9 V, a maximum oscillation frequency f/sub max/ of 167 GHz, and 4.7 ps ring oscillator gate delay. With a 99 GHz dynamic frequency divider and a 19 GHz LNA with 2.2 dB noise figure state-of-the-art results for high-speed digital and analog applications are demonstrated.

3.3 ps SiGe bipolar technology

A SiGe bipolar technology with a transit frequency of 225 GHz and a maximum oscillation frequency of 300 GHz is described. With a ring oscillator gate delay of 3.3 ps and a static frequency divider operating up to 102 GHz input frequency state-of-the-art circuit performance is achieved.