Akshdeep Sharma

Bio: Akshdeep Sharma is an academic researcher from Techno India. The author has contributed to research in topics: Insertion loss & Return loss. The author has an hindex of 6, co-authored 16 publications receiving 140 citations. Previous affiliations of Akshdeep Sharma include McGill University Health Centre & Central Electronics Engineering Research Institute.

Design of novel compact anti-stiction and low insertion loss RF MEMS switch

Abstract: A novel torsional RF MEMS capacitive switch design on silicon substrate is presented. The optimized switch topology such as reduction in up-state capacitance results in insertion loss better than ź0.1 dB till 20 GHz. Off to on state capacitance ratio is also improved by 18 fold and isolation is better than ź43 dB at 9.5 GHz. The achieved on state return loss is ź38 dB as compared to ź21 dB at 9.5 GHz. An optimized reduction in contact area and use of floating metal layer increases the switching speed from 56 to 46 μsec. It also increases the switch reliability by alleviating the stiction.

Design of compact and wide bandwidth SPDT with anti-stiction torsional RF MEMS series capacitive switch

Abstract: This paper presents a new single pole double throw (SPDT) RF MEMS switch design based on a torsional series capacitive switch. The torsional configuration and use of floating metal reduce the stiction probabilities. Use of a single series capacitive switch compared to the conventional approach of a capacitive and series combination, offers compact size, higher bandwidth and superior reliability. The optimized SPDT topology offers a wider bandwidth of 17 GHz (3---20 GHz) with insertion loss of ?0.3 to ?0.4 dB and isolation ?20 to ?44 dB. The proposed structure actuates at 9 V and the contact force varies in the elastic contact regime from 20 to 68 µN for the bias voltage of 10---15 V.

Successful medical treatment of emphysematous pyelonephritis in a renal allograft recipient

Abstract: Emphysematous pyelonephritis in renal allograft recipients is a rare but serious complication. The management of this entity is a subject of controversy in live related donor programs where the absence of a second donor is a key factor influencing surgical removal of the graft. We present a case of emphysematous pyelonephritis in a renal allograft recipient managed successfully with medical therapy alone.

Comparative study of various release methods for gold surface micromachining

Abstract: A comparison of dry and wet release methods for surface micromachining of metallic structures, such as RF MEMS switches, test structures, bridges, and cantilevers is presented. The dry release process is opti- mized by varying the concentration of O2 and CF4 plasma and RF power. The plasma ashing of the sacrificial layer typically results in damage to metallic structures or stress-related deformation due to rise in temperature (>80°C). A wet release process using critical point drying (CPD) has been investigated to realize gold-electro- plated structures with reduced residual stress. The CPD, being a low-temperature (31.1°C) process, is more suitable for compliant structures without any deformation. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)

Current management of emphysematous pyelonephritis.

Abstract: Emphysematous pyelonephritis (EPN) is a severe, necrotizing renal parenchymal infection that is characterized by the production of intraparenchymal gas. EPN predominantly affects female diabetics, and can occur in insulin-dependent and non-insulin-dependent patients in the absence of ureteric obstruction. Nondiabetic patients can also develop EPN, but often have ureteric obstruction and do not seem to develop such extensive disease. One gaseous component-carbon dioxide-is generated by bacterial fermentation of glucose (present in excess in diabetics) and acids. Patients with EPN show relatively vague symptoms initially, but frequently undergo a sudden deterioration in their condition, necessitating urgent medical attention. Treatment of patients with EPN comprises resuscitation, correction of any electrolyte and glucose problems, and administration of antibiotics targeting Gram-negative bacteria. Ureteric obstruction, if present, is relieved by a percutaneous nephrostomy or stent. Definitive management is by percutaneous drainage, except when there is extensive diffuse gas with renal destruction; in this case, a nephrectomy is advised. The requirement for a nephrectomy could potentially be avoided by early diagnosis and treatment of diabetics with urinary infection. With the advent of CT, a staging system of the gas patterns generated in the kidneys of EPN patients has evolved. Risk factors have been defined to aid management.

Retrospective analysis of clinical profile prognostic factors and outcomes of 19 patients of emphysematous pyelonephritis

Abstract: We aimed to study the clinical profile, prognostic factors, and the 6-month outcome of patients with emphysematous pyelonephritis (EPN) All patients admitted with a diagnosis of emphysematous pyelonephritis between January 2001 and July 2007 were included. Overall 19 cases were diagnosed to have emphysematous pyelonephritis. There were 16 females and three males. Fourteen cases had type 2 diabetes mellitus. Fourteen cases had unilateral involvement and five had bilateral involvement. Eleven cases were classified as having class 1 or 2 disease and eight cases had class 3 and 4 disease. E. coli was the most common organism cultured (68.4%). Five cases underwent percutaneous drainage of the collecting system and three cases had nephrectomy of which 10.5% (two with advanced disease) expired. Shock at admission (p = 0.03), serum creatinine >5.0 mg/dl (p = 0.035) and DIC (p = 0.017) were independent poor prognostic factors. There was no difference in the prognosis between patients who had ≥2 or 5.0 mg/dl and DIC at admission are poor prognostic factors. Larger prospective studies are needed to confirm our findings.

Design of novel compact anti-stiction and low insertion loss RF MEMS switch

Abstract: A novel torsional RF MEMS capacitive switch design on silicon substrate is presented. The optimized switch topology such as reduction in up-state capacitance results in insertion loss better than ź0.1 dB till 20 GHz. Off to on state capacitance ratio is also improved by 18 fold and isolation is better than ź43 dB at 9.5 GHz. The achieved on state return loss is ź38 dB as compared to ź21 dB at 9.5 GHz. An optimized reduction in contact area and use of floating metal layer increases the switching speed from 56 to 46 μsec. It also increases the switch reliability by alleviating the stiction.

Design and investigation of a low insertion loss, broadband, enhanced self and hold down power RF-MEMS switch

Abstract: This paper presents a low insertion loss capacitive shunt RF-MEMS switch. In the presented design, float metal concept is utilized to reduce the capacitance in up-state of the device. Float metal switch shows an insertion loss <0.11 dB, a return loss below 26.27 dB up to 25 GHz as compared to 0.81 dB insertion, 8.67 dB return loss for the conventional switch without float metal. OFF state response is same for the both devices. Further pull-in voltage of 12.75 V and switching time of 69.62 µs have been observed in case of the conventional switch whereas device with float metal have 11.75 V and 56.41 µs. Improvement of around 2.5 times in bandwidth and 4 times in input power has been observed without self actuation, hold down problem. The designed switch can be useful at device and sub-system level for multi-band applications.