Mehran Mokhtari

4-bit flash ADC in InP-HBT technology using distributed resistor ladder

4-bit flash A/D converters have been designed and fabricated in InP-HBT technology. The circuit utilizes a novel distributed ladder structure to create the quantization reference voltages. Based on signal-to-noise-and-distortion measurements, the effective number of bits was calculated as 3.9 bits at 10 GS/S. The circuit consumes about 1.9 A from a single 31 V supply and allocates a total area of 3225/spl times/1875 /spl mu/m/sup 2/.

Full Nyquist 4-bit ADC operating at half clock rate in InP-HBT technology

Half clock rate 4-bit flash A/D converters have been designed and fabricated in HRLs InP-HBT-OEIC technology. Two versions of the circuits (with and without on-board divider) have been characterized. The circuits utilize distributed resistor ladder structure to create the quantization reference voltages. Based on signal-to-noise-and-distortion measurements, the typical effective number of bits was calculated to 3.9 bits at 10 GS/S and 4.9 GHz analog input. The two circuit versions (with and without on-board divider) consume about 2.6 and 2.3 A from a single 3.4V supply respectively and allocate a total area of 3675 /spl times/ 1875 /spl mu/m/sup 2/.

Ultrahigh-speed photonic analog-to-digital conversion technologies

This paper summarizes our recent work on high-speed photonic analog-to-digital conversion (A/D) technologies, where picosecond pulses generated by a 10 GHz mode-locked laser source were used to accomplish low-jitter photonic sampling. In addition, we describe our progress in the generation of 40 GHz wavelength-coded pulses for time-interleaved A/D, and the demonstration of photonic bandpass (at 1.6 GHz) Δ-∑ quantizers clocked at 10 GHz.

A 70+GHz BW package for multigigabit IC applications

We have developed a ultra-wideband package technology for multiport ultra-high speed integrated circuit (IC) module applications. The cost-effective, compact, easy-to-assemble package can house any substrate-IC assembly that can be replaced without damaging the mm-wave connectors. A multi-layer substrate processing approach has been developed to achieve low-insertion loss and high-isolation signal lines as well as good thermal management. Careful design of this package suppresses cavity resonances and demonstrates an operating bandwidth of 70+GHz. DC-60+ performance has been demonstrated for a static frequency divider module using this packaging technology.

DC to 50 GHz wideband amplifier with Bessel transfer function

A compact, high-performance active feedback amplifier circuit is presented with more than 50 GHz bandwidth characteristic and less than /spl plusmn/2 ps group delay variation. InP heterogeneous bipolar transistor (HBT) technology is used to design and fabricate this amplifier circuit. Input and output return losses are better than 10 dB up to 50 GHz. The circuit also demonstrates >550 GHz gain-bandwidth product.

Some design issues in ultra high frequency ICs in InP-DHBT technology

Design issues and experiences in some of HRLs recent demonstrated state-of-the-art circuits are presented and discussed. The performance of static dividers and voltage controlled oscillators, has been significantly improved by utilizing the high break-down voltage of the DHBT. The technology utilized here offers an f/sub T/ of about 135 GHz, and a current gain of about 30. The dividers and VCOs designed in this technology exhibit toggling frequencies beyond 100 GHz and phase noise less than -80 dBc/Hz @ 100 KHz from carrier (44 GHz in this case), respectively.

A 60+ GHz packaged static divider implemented in InP DHBT technology

This paper presents a packaged 60+ GHz frequency divider implemented indium phosphide (InP) double-heterostructure bipolar transistor (DHBT) technology. The divider circuit chip was designed using a 135 GHz InP DHBT technology and demonstrated on wafer 100+ GHz toggling frequency. Measurements on the packaged divider showed a 60+ GHz toggle rate. To our knowledge, this is the highest toggling frequency reported on a packaged IC in any technology.