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A switched‐line substrate integrated waveguide 1‐bit phase shifter is designed and measured at 28 GHz. Reconfigurability is achieved through a set of floating metallized vias whose connection to the waveguide top and bottom layers can be controlled using PIN diodes. The reconfigurable vias are used to dynamically create alternative paths having different phase delays. A three‐metal layer printed circuit board stack‐up is employed to fully integrate the diode biasing network and to ease the routing of the bias signal. The high integration of the proposed configuration makes it well suited for the implementation of reconfigurable Butler matrices. The phase shift offset between the two states of this digital 1‐bit phase shifter equals 262° at 28 GHz, leading to a measured figure of merit of 161°/dB, and input 1‐dB compression point over 20 dBm. The total area is 13.72 × 10.9 mm without feeding lines and bias.

Italian Research Group for Gastric Cancer (GIRCG), during the 2013 annual Consensus Conference to gastric cancer, stated that laparoscopic or robotic approach should be limited only to early gastric cancer (EGC) and no further guidelines were currently available. However, accumulated evidences, mainly from eastern experiences, have supported the application of minimally invasive surgery also for locally advanced gastric cancer (AGC). The aim of our study is to give a snapshot of current surgical propensity of expert Italian upper gastrointestinal surgeons in performing minimally invasive techniques for the treatment of gastric cancer in order to answer to the question if clinical practice overcome the recommendation. Experts in the field among the Italian Research Group for Gastric Cancer (GIRCG) were invited to join a web 30-item survey through a formal e-mail from January 1st, 2020, to June 31st, 2020. Responses were collected from 46 participants out of 100 upper gastrointestinal surgeons. Percentage of surgeons choosing a minimally invasive approach to treat early and advanced gastric cancer was similar. Additionally analyzing data from the centers involved, we obtained that the percentage of minimally invasive total and partial gastrectomies in advanced cases augmented with the increase of surgical procedures performed per year (p = 0.02 and p = 0.04 respectively). It is reasonable to assume that there is a widening of indications given by the current national guideline into clinical practice. Propensity of expert Italian upper gastrointestinal surgeons was to perform minimally invasive surgery not only for early but also for advanced gastric cancer. Of interest volume activity correlated with the propensity of surgeons to select a minimally invasive approach.

This paper presents the integration and channel characterization of a highly integrated dual-band digital beamforming space-borne synthetic aperture radar (SAR) receiver. The proposed SAR sensor is a low-cost, lightweight, low-power consumption, and dual-band (X/Ka) dual-polarized module ready for the next-generation space-borne SAR missions. In previous works, by the authors, the design and experimental characterization of each sub-system was already presented and discussed. This work expands upon the previous characterization by providing an exhaustive experimental assessment of the fully integrated system. As it will be shown, the proposed tests were used to validate all the instrument channels in a set-up where the SAR sensor was illuminated by an external source minim the ground reflected waves. Test results demonstrate how the system channels are properly operating allowing the reception of the input signals and their processing in the digital domain. The possibility to easily implement a calibration procedure has also been validated to equalize, in the digital domain, the unavoidable amplitude differences between the different channels.

A polarization rotator based on substrate integrated waveguide (SIW) is proposed in this article. The rotator is designed as a dual-band, single-layer, frequency-selective surface (FSS) that transmits a wave rotated of 90° with respect to the incident one in one of the two bands maintaining unchanged the polarization in the other one. Other than the design and characterization of the rotator, its application to a linear-to-circular dual-band polarizer is also investigated. To this purpose, the rotator is coupled to a conventional meander line polarizer generating orthogonal circular polarizations (CP) in the two bands. This configuration is useful in SatCom applications where the required high isolation between TX and RX channels is obtained assigning orthogonal polarizations to the two bands. As a design example, a prototype is designed and experimentally validated in the SatCom K-/Ka -bands. Measured performance shows an isolation between the TX and RX channels of more than 35 dB and insertion losses which do not exceed 1.5 dB in the two operating bands.

This study presents the first monolithically integrated full-duplex front-end for K/Ka satellite communication phased arrays. A 0.25 μm SiGe:C BiCMOS process was used to develop the integrated circuit. The receive and transmit channels are united into a common port through a novel duplexer. For each RF channel, the bias currents, the active channels and the power amplifier operation mode can be controlled through a serial bus. Amplitude and phase control are provided with fine granularity (65,536 states). In transmit mode, each channel provides 37.3 dB of gain with 12.9 dBm output power at 1-dB compression. In receive mode, 33.7 dB gain is measured with a noise figure of 3.2 dB. The amplitude/phase root-mean-square errors within the transmit (29.5–30.8 GHz) and receive (19.7–21 GHz) bands are below 0.7 dB/ 6.4 ° and 0.26 dB/ 1.1 ° , respectively. The chip occupies 1.64 × 3.5 m m 2 and it consumes 81 and 15.5 mW per transmit and receive channels, respectively. The use of a Doherty power amplifier with a novel dynamic adaptive bias circuit led to a 31% reduction of the total dc array power consumption.

A novel dual-band cylindrical reflector antenna with a hat feed is presented. A horn in a parallel-plate waveguide illuminates a parabolic surface to generate a TEM wave that is used to illuminate a corrugated feed. The feed is designed using a double step corrugation optimized to obtain good radiation patterns and good matching on the two bands of interest. The design of the grooves is based on the analysis of the radiation characteristics of the corrugated surface. In particular, the power re-radiated by the corrugation is considered to ascertain features which prove to be extremely useful in simplifying the design of the feed. The solution proposed in this communication makes possible to realize an antenna with compact size and low cost without sacrificing efficiency and compliance with radiation masks.

This paper presents the first experimental assessment of a highly integrated dual-band dual-polarized antenna tile designed for synthetic aperture radar (SAR) digital beamforming (DBF) satellite applications. The demonstrator described in this paper is the first comprehensive experimental validation of an RF module providing the X-band and Ka-band (9.6- and 35.75-GHz) operation with custom downconversion stages. All the antennas, transitions, and downconversion chips are integrated in the same antenna tile fabricated using a customized 15-layer high density interconnect process. The designed tile goes to the limits of the proposed technology and for the high trace density and for the size of the vertical transitions. The proposed results represent the state of the art in terms of compactness for a DBF SAR RF module even though the demonstrator was manufactured with a standard low-cost technology. The experimental assessment proves the validity of the proposed manufacturing and integration approaches showing a substantial agreement between the performance of the individual blocks and of the integrated system.

Phased arrays are one of the most critical blocks in 5G networks. In the case of the point-to-multipoint link, they have to provide beam reconfigurability over a large scanning range while maintaining a low profile and a limited cost. Moreover, operation at millimeter wave frequencies poses several critical challenges especially in terms of integration and, in turn, analysis. This work provides an introduction to the different simulation challenges involved in the design of a phased array differentiating them into two categories: i) cross-domain effects due to the different integration and packaging technologies present in the array along its vertical dimension and ii) mutual coupling effects taking place across the array horizontal dimension. As a design example, an ultra-low profile Magneto Electric (ME) dipole antenna design for 5 G applications is reported.

This paper introduces a gain enhancement technique for monolithically integrated monopole antennas. The proposed configuration has been designed in a standard 0.13 µm SiGe BiCMOS process. The gain improvement was achieved by combining the on-chip monopole antenna with some parasitically coupled Split Ring Resonators (SRRs). The size of the SRR was firstly fixed to adapt their length to the monopole geometry while their resonant frequency was fine-tuned by using a capacitive load which serves to control the resonance frequency without changing their length. Thanks to this solution, it was possible to achieve a gain improvement of about 1 dBi with respect to an unloaded monopole. An experimental assessment showed a maximum measured antenna gain of 1.61 dB at 81.5 GHz and the antenna maintains good performance from 77 to 87 GHz.

International audience; This paper introduces an experimental characterization of substrate integrated waveguide (SIW) components integrated in a benzocyclobutene-based interposer for WR10-band applications. High performance SIWs were experimentally validated, with a measured attenuation constant of 0.39 dB/mm and a quality factor of 27 at 90 GHz. The attenuation constant remains equal to 0.4 dB/mm between 85 GHz and 110 GHz and the quality factor reaches 40 in the upper end of the band. These results show the benefits offered by using benzocyclobutene 3D packaging for the realization of high performance passive circuits with lower cost and higher electrical performance as compared to standard CMOS technologies and concurrent packaging technologies.

The implementation of backhauling links poses several challenges to the designers which are requested to limit the hardware costs in the framework of complex millimeter wave radio systems. This work presents a monolithically integrated E-band I/Q receiver covering the whole bandwidth from 71 to 86 GHz. The chip was implemented in a 55 nm SiGe BiCMOS technology which allows reaching a high level of integration. The receiver is based on a Low Noise Amplifier (LNA) stage and a Variable-Gain Amplifier (VGA) which provide a −11 dBm IP1dB. A double balanced mixer provides I/Q baseband outputs through a reduced-size differential phase shifter which allows to contain the chip size to 1.8 mm2.

This work proposes an 8×8 D-band antenna array constructed from 64 stepped horns. The structure is designed to be machined from single metallic block adhered with an additional bottom metallic cover. The proposed design can be realized using low-cost commercially accessible milling tools. The configuration at hand is composed of three building blocks: transition, power divider and horn radiator. The array footprint has a volume of 30×30×8 mm3 while a 29.5% fractional bandwidth is achieved from 130 till 175 GHz where reflection coefficient is lower than 7.8 dB. Radiation characteristics are investigated for both single horn radiator and 8×8 antenna arrays where the obtained average gain values are 15.25 and 32 dBi, respectively. Directive pencil beam, required for 5G backhauling communication, has been confirmed for 8×8 antenna array where the half power beam width is 1.5° for both E and H-planes while grating lobes appear at 28°.

Some recent work on Ka Band Circular Linear-to-Polarizers carried out at the Microwave Group of University of Calabria (Italy) are presented. Four types of Linear Polarization (LP) to Circular Polarization (CP) converters, including three transmission type and one reflection type, are developed by using low cost standard Printed Circuit Board (PCB) technology. Experiments show that good performances are obtained for all proposed solutions.

Two gain enhancement techniques for monolithically integrated monopole antennas are presented in this work. The proposed configurations have been designed in a standard 0.13 μm SiGe BiCMOS process. In the first one, Split Ring Resonators (SRRs) have been combined with Localized Backside Etching (LBE). These etched parts are removed locally from the silicon substrate, reducing the losses and thus contributing to increase the gain of the monopole antenna. In the second technique, an on-chip monopole antenna is paired with parasitically coupled SRRs. The latter elements are tuned using a capacitive load which serves to control their resonance frequency without changing their physical dimensions. These techniques have been compared with an unloaded monopole and they provide a gain enhancement of about 1 dBi within the band of interest without significantly increasing the overall antenna size which was fixed to 1.296 × 1.508 mm2.

This paper presents a new improved gain array configuration well suited for mid-range V-band backhauling applications. The proposed solution is based on a cavity-backed shorted annular patch (SAP) antenna loaded with a parasitic patch element for gain maximization. This solution is proved by designing and measuring a 4 × 4 array which presents a reflection coefficient bandwidth covering the frequencies from 58.7 to 63.25 GHz (7.6% at 60 GHz). The experimentally validated array gain is equal to 18 dBi corresponding to 37.9% of aperture efficiency. The antenna and array configurations presented in this paper are optimized to minimize the manufacturing cost and complexity. This result is achieved through a novel beamforming network (BFN) configuration, implemented using a dual-layer substrate-integrated waveguide (SIW) technology, and partly integrated on the array aperture. The achieved results demonstrate how the performance of the cavity backed SAP array is comparable to the ones achieved with more complex and expensive solutions.

Magneto Electric (ME) dipoles have been widely studied over the last few years. They are becoming increasingly popular as they allow to generate a wide bandwidth in a printed circuit board (PCB). Nevertheless, their principle of operation requires the use of relatively thick substrates (i.e. about 0. 25λ 0 , where λ 0 is the free-space wavelength) thus resulting in a bulky stack-up. This work tackles this problem by proposing a new type of low -profile ME dipole. The proposed configuration is fed using a slot-coupled microstrip line feed and it employs bandwidth enhancement solutions previously used in metal-only structures. As a result, an ultrathin antenna is achieved which operates over a 20% bandwidth at Ka-band while using an ultrathin dielectric layer being the antenna thickness equal to 0.082 λ 0 . Moreover, the antenna has a gain of about 5.5 dBi across the entire bandwidth, which makes the proposed design suitable for next generation 5G base stations.

this work proposes a novel design of two-layered antenna array targeting the D-Band region of the spectrum, likely to become the next commercial battleground for millimeter-wave communications. The design is basically an 8 × 8 hollow metallic cavity backed antenna array which exhibits a thin planar footprint with volume of $( 30.1 \times 26.4 \times 1.2$ mm3) and it is capable of covering the 153-161 GHz, which corresponds to 5.2% of FBW. Radiation characteristics are investigated for both 2 × 2 subarray and the whole 8 × 8 antenna where the obtained peak gain values are 12.4 dBi and 22.4 dBi, respectively. The achieved HPBW is 3.5° whereas grating lobes appears at 29°. These values are in-line with the requirements of next-generation point to point communications where short links are foreseen. Index Terms— Antenna array, backhauling communications, D-Band, millmeter-wave, metlic waveguide, slotted antenna.

A broadband and broad-angle linear-to-circular polarization converter based on a dual-layer substrate is presented. The elementary cell of the proposed converter is composed by a Jerusalem Cross (JC). The design procedure is based on transmission line circuit theory and on full-wave unit cell analysis in frequency domain. Simulated results demonstrate a 24% axial ratio bandwidth for an incidence angle θ = ± 50° in both x-z and y-z planes. The proposed converter provides a unique combination of wide bandwidth, thin profile, and stable response with respect to the angle of incidence. It can be integrated to any linearly polarized antenna to generate circular polarization without affecting the antenna performances.

A new configuration of a planar grid array antenna for automotive radar applications operating in the 77–81 GHz frequency band is introduced. The proposed array is based on miniaturized loop elements, which are designed to maintain the mutual interelement distance along the azimuthal plane to less than half free-space wavelength, thus allowing a better scanning performance in the final radar system. Moreover, to enhance the gain bandwidth performance, the antenna adopts multiresonant cells realized using variably dimensioned radiation elements. The proposed design was validated experimentally and it is fully compliant with multichannel monolithic microwave integrated circuits (MMICs) designed for automotive radar sensor applications.

BACKGROUND Patient-reported outcomes associated with different bowel reconstruction techniques following anterior resection for rectal cancer are still a matter of debate. OBJECTIVE This study aimed to assess quality of life and bowel function in patients who underwent colonic J-pouch or straight colorectal anastomosis reconstruction after low anterior resection. DESIGN Bowel function and quality of life were assessed within a multicenter randomized trial. Questionnaires were administered before the surgery (baseline) and at 6, 12, and 24 months after surgery. SETTINGS Patients were enrolled by 19 centers. The enrollment started in October 2009 and was stopped in February 2016. The study was registered at www.clinicaltrials.gov (Identifier: NCT01110798). PATIENTS Patients who underwent low anterior resection for primary mid-low rectal cancer and who were randomly assigned in a 1:1 ratio to receive either stapled colonic J-pouch or straight colorectal anastomosis were selected. MAIN OUTCOME MEASURES The primary outcomes measured were quality of life and bowel function. RESULTS Of the 379 patients who were evaluable, 312 (82.3%) completed the baseline, 259 (68.3%) the 6-month, 242 (63.9%) the 12-month, and 199 (52.5%) the 24-month assessment. Bowel functioning and quality of life did not significantly differ between arms for almost all domains. The total bowel function score, the urgency, and the stool fractionation scores significantly worsened after surgery and remained impaired over time in both arms (p < 0.0032), whereas constipation improved after surgery but recovered to baseline levels from 1 year onward (p < 0.0036). All patients showed a significant and continuous improvement in emotional functioning (p < 0.0013) and future perspective (p < 0.0001) from baseline to the end of the study. LIMITATIONS Limitations of the study include missing data, which increased over time; the possibility that some treatments have slightly changed since the study was conducted; and investigators not blind to treatment allocation. CONCLUSION The findings of this study do not support the routine use of colonic J-pouch reconstruction in patients with rectal cancer who undergo a low anterior resection. See Video Abstract at http://links.lww.com/DCR/B328. BOLSA J COLONICA O RECONSTRUCCION COLORRECTAL RECTA DESPUES DE RESECCION ANTERIOR BAJA PARA CANCER RECTAL: IMPACTO EN LA CALIDAD DE VIDA Y LA FUNCION INTESTINAL: UN ESTUDIO ALEATORIZADO PROSPECTIVO MULTICENTRICO: Los resultados informados por el paciente asociados con diferentes tecnicas de reconstruccion intestinal despues de la reseccion anterior para el cancer de recto aun son tema de debate.Evaluar la calidad de vida y la funcion intestinal en pacientes que se sometieron a una bolsa en J colonica o reconstruccion de anastomosis colorrectal recta despues de una reseccion anterior baja.La funcion intestinal y la calidad de vida se evaluaron en un ensayo aleatorizado multicentrico. Los cuestionarios se administraron antes de la cirugia (basal) y a los 6, 12 y 24 meses despues de la cirugia.Los pacientes fueron incluidos en 19 centros. La inscripcion comenzo en Octubre de 2009 y se detuvo en Febrero de 2016. El estudio se registro en www.clinicaltrials.gov (Identificador: NCT01110798).Pacientes que se sometieron a reseccion anterior baja por cancer rectal primario medio-bajo y que fueron aleatorizados en una proporcion de 1: 1 para recibir bolsa J colonica con grapas o anastomosis colorrectal recta.calidad de vida y funcion intestinal.De los 379 pacientes que fueron evaluables, 312 (82.3%) completaron la evaluacion inicial, 259 (68.3%) a los 6 meses, 242 (63.9%) a los 12 meses y 199 (52.5%) a los 24 meses. . El funcionamiento intestinal y la calidad de vida no difirieron significativamente entre los dos grupos en casi todos los dominios. La puntuacion total de la funcion intestinal, la urgencia y las puntuaciones de fraccionamiento de las heces empeoraron significativamente despues de la cirugia y continuaron con el tiempo extra en ambos grupos (p

Colorectal cancer (CRC) is the third most common cancer worldwide, the 5% of CRC are hereditary. Among hereditary forms of CRC the most frequent is Hereditary Nonpolyposis Colorectal Cancer (HNPCC). HNPCC is an autosomal dominant genetic disease. Molecular basis of HNPCC are linked to genetic alterations, involving several mismatch repair (MMR) genes. Diagnosis of HNPCC is frequently difficult: HNPCC diagnosis process starts from family medical history and genetic counselling and continue with molecular diagnosis and genetic tests which often identify MMR genes mutation. In HNPCC the role of screening is irreplaceable for prevention and early diagnosis of CRC and extracolic cancer, such as endometrium, ovary, urothelium, stomach, small bowel, pancreas, brain, biliary ducts neoplasms. Surgical management of HNPCC is significantly different between colonic and rectal cancer. The main problem in surgical approach for HNPCC patients is related to the possibility of developing metachronous colorectal cancer. The choice is always between extensive and segmental resection. The aim of this study is to give some practical indications to surgeons for the management of HNPCC patients.