Broadband Receiver Electronic Circuits for Fiber-Optical Communication Systems

The exponential growth of internet traffic drives datacenters to constantly improve their capacity. As the copper based network infrastructure is being replaced by fiber-optical interconnects, new industrial standards for higher datarates are required. Several research and industrial organizations are aiming towards 400 Gb Ethernet and beyond, which brings new challenges to the field of high-speed broadband electronic circuit design. Replacing OOK with higher M-ary modulation formats and using higher datarates increases network capacity but at the cost of power. With datacenters rapidly becoming significant energy consumers on the global scale, the energy efficiency of the optical interconnect transceivers takes a primary role in the development of novel systems. There are several additional challenges unique in the design of a broadband shortreach fiber-optical receiver system. The sensitivity of the receiver depends on the noise performance of the PD and the electronics. The overall system noise must be optimized for the specific application, modulation scheme, PD and VCSEL characteristics. The topology of the transimpedance amplifier affects the noise and frequency response of the PD, so the system must be optimized as a whole. Most state-of-the-art receivers are built on high-end semiconductor SiGe and InP technologies. However, there are still several design decisions to be made in order to get low noise, high energy efficiency and adequate bandwidth. In order to overcome the frequency limitations of the optoelectronic components, bandwidth enhancement and channel equalization techniques are used. In this work several different blocks of a receiver system are designed and characterized. A broadband, 50 GHz bandwidth CB-based TIA and a tunable gain equalizer are designed in a 130 nm SiGe BiCMOS process. An ultra-broadband traveling wave amplifier is presented, based on a 250 nm InP DHBT technology demonstrating a 207 GHz bandwidth. Two TIA front-end topologies with 133 GHz bandwidth, a CB and a CE with shunt-shunt feedback, based on a 130 nm InP DHBT technology are designed and compared

Wideband integrated circuits for optical communication systems

The exponential growth of internet traffic drives datacenters to constantly improvetheir capacity. Several research and industrial organizations are aiming towardsTbps Ethernet and beyond, which brings new challenges to the field of high-speedbroadband electronic circuit design. With datacenters rapidly becoming significantenergy consumers on the global scale, the energy efficiency of the optical interconnecttransceivers takes a primary role in the development of novel systems. Furthermore,wideband optical links are finding application inside very high throughput satellite(V/HTS) payloads used in the ever-expanding cloud of telecommunication satellites,enabled by the maturity of the existing fiber based optical links and the hightechnology readiness level of radiation hardened integrated circuit processes. Thereare several additional challenges unique in the design of a wideband optical system.The overall system noise must be optimized for the specific application, modulationscheme, PD and laser characteristics. Most state-of-the-art wideband circuits are builton high-end semiconductor SiGe and InP technologies. However, each technologydemands specific design decisions to be made in order to get low noise, high energyefficiency and adequate bandwidth. In order to overcome the frequency limitationsof the optoelectronic components, bandwidth enhancement and channel equalizationtechniques are used. In this work various blocks of optical communication systems aredesigned attempting to tackle some of the aforementioned challenges. Two TIA front-end topologies with 133 GHz bandwidth, a CB and a CE with shunt-shunt feedback,are designed and measured, utilizing a state-of-the-art 130 nm InP DHBT technology.A modular equalizer block built in 130 nm SiGe HBT technology is presented. Threeultra-wideband traveling wave amplifiers, a 4-cell, a single cell and a matrix single-stage, are designed in a 250 nm InP DHBT process to test the limits of distributedamplification. A differential VCSEL driver circuit is designed and integrated in a4x 28 Gbps transceiver system for intra-satellite optical communications based in arad-hard 130nm SiGe process

Osteolytic bone destruction resulting from relapse of a testicular tumour 23 years after inguinal orchiectomy and adjuvant chemotherapy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Late relapse of a testicular germ cell tumour is an uncommon occurrence. We report a case of osteolytic bone metastasis appearing 23 years after the initial treatment of a metastatic testicular mixed tumour (choriocarcinoma and embryonal carcinoma). This is one of the longest periods of recurrence reported for testicular germ cell tumours.</p> <p>Case presentation</p> <p>A 52-year-old Caucasian man who underwent a right inguinal orchiectomy due to testicular tumour in 1984 presented to our outpatient clinic in a generally bad condition of health and with severe pain of his right hip joint and os ischii caused by osteolytic metastasis.</p> <p>Conclusions</p> <p>This case emphasizes the need for a life-long follow-up of patients with primary metastatic testicular cancer.</p

A Case Report of Urinary Bladder Carcinosarcoma and Review of the Literature

Carcinosarcoma of the bladder is an unusual tumour characterized by a combination of malignant epithelial and soft tissue elements. Most of the reported cases have been case reports or small series. Optimal treatment is uncertain. We herein report our experience in such a case treated with transurethral resection followed by radiotherapy with adverse final outcome. Treatment of bladder carcinosarcomas should be aggressive and multimodal but optional treatment is still unknown. Radiotherapy alone is insufficient as a treatment option of these aggressive tumors

Clinical Study Ureteroscopic Laser Treatment of Upper Urinary Tract Urothelial Cell Carcinomas: Can a Tumour Free Status Be Achieved?

Introduction. In cases of anatomic or functional single kidney with urothelial tumours of the upper urinary tract, the endoscopic laser ablation has proven efficacious. Based on the knowledge that low-grade, low-stage upper tract transitional cell carcinomas rarely progress to invasive lesions, indications for endoscopic laser ablation have expanded to include patients with bilateral functioning kidneys and low-grade tumours. The question that remains to be answered is whether endoscopic laser ablation has the ability to completely eradicate upper urinary tract tumours. Methods. We performed in 25 patients in a period of 11 years 288 ureteroscopies and, if needed, laser ablation of upper urinary tract tumours in imperative indication. Results. In 32% of the patients the cancer remained even after several laser sessions. 64% of patients were tumour free after one or more laser sessions but remained clear only for the next 3 months. Only 1 patient was tumour free for a period of 68 months after 1 session of laser treatment. The procedure had low complication rates. Conclusion. The laser technology and the introduction of small diameter semirigid and flexible ureteroscopes made ablation of upper urinary tract tumours possible and safe. Nevertheless a complete resection of the carcinomas is rarely possible

Perforation of the Urinary Bladder Caused by Transurethral Insertion of a Pencil for the Purpose of Masturbation in a 29-Year-Old Female

The urethra is a usual site of introduction of foreign bodies for autoerotic stimulation. We present an unusual case of bladder perforation caused by foreign body that was self-inserted in the urethra and consequently slipped inside the bladder in a 29-year-old female patient with psychiatric disease. The patient was referred to our department for macroscopic hematuria and abdominal pain. Imaging studies revealed the presence of a foreign body in the pelvic area which had perforated the left lateral wall of the bladder. The foreign body was removed via open cystotomy. In psychiatric patients hematuria and pelvic pain may result from insertion of a foreign body in the bladder usually during masturbation

Psychosocial distress and functioning of Greek youth with cystic fibrosis: a cross-sectional study

BACKGROUND: To assess psychosocial functioning and distress of children and adolescents with cystic fibrosis compared to healthy controls. METHODS: Thirty-six patients with cystic fibrosis aged 8–18 years (24 boys, mean age ± SD: 11.5 ± 2.6 years) and 31 sex- and age-matched healthy control subjects (18 boys, mean age ± SD: 12 ± 2.5 years) were enrolled in the study. In order to assess the self-esteem, social adjustment, and family functioning of these young people, the Culture-free Self-esteem Inventory, the Social Adjustment Scale–Self-Report, and the Family Assessment Device were administered. Emotional/ behavioral problems were assessed through the Youth Self Report and the Child Behavior Checklist given to both the subjects and their parents. RESULTS: No significant differences were found for self-esteem between the two study groups. Regarding social adjustment, children with cystic fibrosis reported significantly worse friendship and overall adjustment (P < 0.05). Moreover, no difference was found in the levels of family functioning between the two groups. No significant differences between the groups were found in emotional/ behavioral problems from the self-reports. On the contrary, parents of children with cystic fibrosis reported significantly higher levels of withdrawal/ depression, thought problems, and delinquent behavior (P ≤ 0.01) as compared to controls. CONCLUSIONS: Children and adolescents with cystic fibrosis appear to be a psychosocially vulnerable group. A biopsychosocial approach should emphasize the assessment and treatment of the psychosocial distress of these patients alongside multiple somatic treatments

A 112 Gb/s Radiation-Hardened Mid-Board Optical Transceiver in 130-nm SiGe BiCMOS for Intra-Satellite Links

We report the design of a 112 Gb/s radiation-hardened (RH) optical transceiver applicable to intra-satellite optical interconnects. The transceiver chipset comprises a vertical-cavity surface-emitting laser (VCSEL) driver and transimpedance amplifier (TIA) integrated circuits (ICs) with four channels per die, which are adapted for a flip-chip assembly into a mid-board optics (MBO) optical transceiver module. The ICs are designed in the IHP 130 nm SiGe BiCMOS process (SG13RH) leveraging proven robustness in radiation environments and high-speed performance featuring bipolar transistors (HBTs) with fT/fMAX values of up to 250/340 GHz. Besides hardening by technology, radiation-hardened-by-design (RHBD) components are used, including enclosed layout transistors (ELTs) and digital logic cells. We report design features of the ICs and the module, and provide performance data from post-layout simulations. We present radiation evaluation data on analog devices and digital cells, which indicate that the transceiver ICs will reliably operate at typical total ionizing dose (TID) levels and single event latch-up thresholds found in geostationary satellites

The H2020-SPACE-SIPHODIAS project: Space-grade optoelectronic interfaces for photonic digital and analogue very-high-throughput satellite payloads

The EU-SIPhoDiAS project deals with the development of critical photonic building blocks needed for high-performance and low size, weight, and power (SWaP) photonics-enabled Very High Throughput Satellites (VHTS). In this presentation, we report on the design and fabrication activities during the first year of the project concerning the targeted family of digital and microwave photonic components. This effort aims to demonstrate components of enhanced reliability at technology readiness level (TRL) 7. Specifically, with respect to microwave photonic links, we report: (i) the design of Ka and Q-bands analogue photodetectors that will be assembled in compact packages, allowing for very high bandwidth per unit area and (ii) on the design of compact V-band GaAs electro-optic modulator arrays, which use a folded-path optical configuration to manage all fiber interfaces packaged opposite direct in-line RF feeds for ease of board layouts and mass/size benefits. With respect to digital links, we report on the development of 100 Gb/s (4 x 25 Gb/s) digital optical transceiver sub-assemblies developed using flip-chip mounting of electronic and opto-parts on a high-reliability borosilicate substrate. The transceiver chipset developed specifically for this project refers to fully-custom 25 Gb/s radiation hard (RH) VCSEL driver and TIA ICs designed in IHP’s 130 nm SiGe BiCMOS Rad-Hard process

VCSEL Integrated Circuit Drivers: A Review

Vertical cavity surface emitting lasers (VCSELs) are considered to be an attractive choice for short-range optical interconnects in data acquisition systems. As the limited bandwidth of VCSEL is the major obstacle to achieving higher data rates in these optical systems, significant effort has been made to develop efficient VCSEL drivers in CMOS and SiGe BiCMOS processes to increase data rate while consuming less power. This paper sheds light on the design choices for the technology, modulation format, VCSEL configuration, and pre-emphasis techniques for a targeted performance based on an overview of the popular approaches to implementing low-power high-speed VCSEL drivers, with an emphasis on the challenges associated with designing drivers suitable for working in harsh environments