Analysis and equalization of data-dependent jitter

Data-dependent jitter limits the bit-error rate (BER) performance of broadband communication systems and aggravates synchronization in phase- and delay-locked loops used for data recovery. A method for calculating the data-dependent jitter in broadband systems from the pulse response is discussed. The impact of jitter on conventional clock and data recovery circuits is studied in the time and frequency domain. The deterministic nature of data-dependent jitter suggests equalization techniques suitable for high-speed circuits. Two equalizer circuit implementations are presented. The first is a SiGe clock and data recovery circuit modified to incorporate a deterministic jitter equalizer. This circuit demonstrates the reduction of jitter in the recovered clock. The second circuit is a MOS implementation of a jitter equalizer with independent control of the rising and falling edge timing. This equalizer demonstrates improvement of the timing margins that achieve 10/sup -12/ BER from 30 to 52 ps at 10 Gb/s

Indirect test of M-S circuits using multiple specification band guarding

Testing analog and mixed-signal circuits is a costly task due to the required test time targets and high end technical resources. Indirect testing methods partially address these issues providing an efficient solution using easy to measure CUT information that correlates with circuit performances. In this work, a multiple specification band guarding technique is proposed as a method to achieve a test target of misclassified circuits. The acceptance/rejection test regions are encoded using octrees in the measurement space, where the band guarding factors precisely tune the test decision boundary according to the required test yield targets. The generated octree data structure serves to cluster the forthcoming circuits in the production testing phase by solely relying on indirect measurements. The combined use of octree based encoding and multiple specification band guarding makes the testing procedure fast, efficient and highly tunable. The proposed band guarding methodology has been applied to test a band-pass Butterworth filter under parametric variations. Promising simulation results are reported showing remarkable improvements when the multiple specification band guarding criterion is used.Peer ReviewedPostprint (author's final draft

Equalization of Third-Order Intermodulation Products in Wideband Direct Conversion Receivers

This paper reports a SAW-less direct-conversion receiver which utilizes a mixed-signal feedforward path to regenerate and adaptively cancel IM3 products, thus accomplishing system-level linearization. The receiver system performance is dominated by a custom integrated RF front end implemented in 130-nm CMOS and achieves an uncorrected out-of-band IIP3 of -7.1 dBm under the worst-case UMTS FDD Region 1 blocking specifications. Under IM3 equalization, the receiver achieves an effective IIP3 of +5.3 dBm and meets the UMTS BER sensitivity requirement with 3.7 dB of margin

An HTS Quasi-One junction SQUID-based periodic threshold comparator for a 4-bit superconductive flash A/D converter

An all high-Tc periodic threshold comparator for application in a 4-bit superconductive A/D converter has been realized and tested. The theoretical threshold curve of the comparator is calculated and compared to the measured results. Furthermore, the thermal noise immunity and the influence of flux-flow are considered, resulting in practical design constraints for the comparator circui

A micropower centroiding vision processor

Published versio

Development of a test bench for the electronics of ionizing radiationdetectors

In the present final degree project a low cost test bench is presented. A test bench is an envi-ronment used to verify the correctness of devices. In this case, the test bench is used to test preamplifiers and digitizers of the nuclear instrumentation laboratory. These instruments are used for ionizing particle detection. The initial problematic of the project was to investigate if it was possible to do a testing working bench with a cheap digital circuit as microcontrollers. After a study of the actual market, the Arduino Due was chosen. Arduino is an open-source electronics platform based on easy-to-use hardware and software. In the initial stage of the project, the attention was focused on the documentation about the Arduino boards. It was quickly observed that the sampling time delivered by the Aduino IDE was not acceptable for a nuclear test bech. When inquiring into the technical datasheet of the Atmel SAM3X microchip, used by the Arduino Due, it was achieved making signals with sampling time acceptable for nuclear instrumentation. Once discovered the potential of Arduino Due, a GUI was made to fully customize the shape of the pulses generated by the Arduino board. Therefore, the development of a cheap testing workbench was achieved