This paper presents a novel synthesis for bandwidth switchable bandpass filters using Semi-conductor Distributed Doped Areas (ScDDAs) as active elements. A co-design method is proposed with a global ...and simultaneous conception for the active and the passive parts of the switchable filters. The ScDDAs, integrated in the silicon substrate, are able to commute from half-wavelength open-ended stubs to quarter-wavelength short-circuited ones. This co-design method offers a great flexibility and allows to integrate the active elements directly in the substrate, therefore avoiding any soldering of components. The synthesis is developed for the two-states of the active elements and applied, as a proof of concept, to a four-pole bandwidth switchable bandpass filter. This filter operates at 5 GHz with a 50 % bandwidth in the OFF-state (when the stubs are terminated by an open-circuit) and with a 70 % bandwidth in the ON-state (when the stubs are short-circuited). For this filter, the synthesis is detailed in the two-states allowing to choose the two desired bandwidths. A good fitting is obtained for these results proving the viability of such an approach.
This paper deals with the synthesis of high-magnetization porous silicon-based nanocomposites. Using well-controlled organometallic synthesis of ferromagnetic FeCo nanoparticles, the impregnation of ...mesoporous silicon has been performed by immersion of porous silicon in a colloidal solution. The technique was optimized by controlling the temperature, the immersion duration, and the solvent nature. The characterization of the nanocomposites showed a homogeneous filling of the pores and a high magnetization of 135 emu/cm
. Such composites present a great interest for many applications including data storage, medical instrumentations, catalysis, or electronics.
In order to develop high performances and miniaturized devices for RF communications, monolithic integration becomes an important challenge for microelectronics industries. Bandpass filters and ...common-mode filter have been integrated on 6-in porous silicon (PS)/silicon hybrid substrates with PS regions under passive devices. An improvement of the rejection level on common mode was demonstrated on PS regards to low-resistivity silicon. Furthermore, the bandwidth differential was increased regards to bulk silicon and, thus, allows the development of devices for high-speed communications systems.
This letter presents a novel 5-GHz transmitter/ receiver (TX/RX) single-pole double-throw (SPDT) switch designed on a silicon substrate. The novelty of this SPDT switch is the possibility it offers ...to simultaneously design the transmission lines and the active elements, without packaging and consequently its parasitic effects and frequency limitations. The device is intended to be easily integrated into a system with a more complex function, e.g., with amplifiers and antennas. The codesign method offers great flexibility in the positioning and sizing of the active elements, i.e., semiconductor distributed doped areas (ScDDAs), which are integrated n + pp + junctions, in order to obtain the best possible performances in both aspects. A demonstrator provides proof of the concept. In RX-mode, the insertion loss (IL) is 0.9 dB with isolation (ISO) higher than 30 dB. In TX-mode, IL is 2.38 dB and ISO is higher than 43 dB.
This letter presents a continuously tunable resonator with a novel triangular doped area on a silicon substrate. The resonator and its tunable element (an n + pp + junction) are co-designed in the ...same flow, leading to new tradeoffs and novel behaviors. The co-design flexibility allows the active area to be drawn with any doping shape. The base of the triangular doped area is located at the end of a stub. Consequently, when the junction is forward biased with a low bias voltage, the resonator is ended by a short circuit at the triangle base. Then, by increasing the voltage, the short-circuit plan moves continuously until it reaches the top of the triangle, thereby decreasing the length of the short-circuited stub. Besides, a demonstrator validates the concept and offers a continuous resonant frequency tunability of 50%, from 2.2 to 3.3 GHz, with a bias voltage from 0 to −1.3 V.
To study the effect of various n-type substrates on high-frequency inductor performances, several devices were integrated on porous silicon (PS), silicon (Si), and glass. Both n-type mesoporous Si ...and mesoporous/macroporous Si bilayers were fabricated. The analysis further shows that PS reduces significantly the substrate losses. Indeed, higher quality factors have been obtained for the inductors integrated on PS than on the Si substrate and particularly in the case of bilayer structures. These original results can be added to p-type PS performances already shown in the literature. Then, this work demonstrates that PS can also be a promising candidate for the integration of passive and active devices on n-type silicon.
•Porous silicon/silicon hybrid substrates realized for industrial device integration.•Monolithic integration of active and passive devices for RF function.•Electrical characterization of fully ...functional ESD diodes.•Improvement of RF noise rejection versus original product on bulk silicon.
This work reports that silicon/porous silicon mixed substrates can be successfully used for monolithic integration of RadioFrequency (RF) passive and active devices. To validate this concept, RF low pass filters for interference filtering between 0.9 and 2GHz and electrostatic discharge protection diodes were integrated on 6″ mixed substrates. At first, the electrical characterization revealed that both active and passive components integrated on the mixed substrate are fully functional. In addition, it was shown that filter performances are clearly improved if the passive devices are integrated on localized porous silicon instead of on lossy p+-type silicon.
Microelectronics, microfluidics and energy storage are among the application fields that could take advantage of the localized protection inside deep cavities or textured substrates. However, ...standard masking techniques used in the industry, such as photolithography, can be limited when applied to wafers with high aspect ratio topography. We have developed a maskless technique based on the anisotropy manipulation of the deposition and etching of a plasma-polymerized fluoropolymer layer, fully protecting the horizontal surfaces of deep trenches while keeping their sidewalls free of any protective layer. We were able to mask trenches with an aspect ratio up to ∼10, and depth of ∼100 μm. As a proof of concept for this localized protection technique, we demonstrate the formation of porous silicon layers (up to 8 μm in thickness) performed by anodization on these walls, while the horizontal surfaces were fully protected.
This paper presents a novel way to switch dual-behavior resonator (DBR) filters without any additional active surface-mount components. By using a semiconductor substrate, we were able to ...simultaneously co-design the filters and semiconductor distributed doped areas (ScDDAs) with integrated N+PP+ junctions as active elements. These ScDDAs act as electrical vias in the substrate, which makes it possible to have an open-circuited resonator in the OFF state and a short-circuited resonator in the ON state, and, consequently, to control the transmission zeroes of the filters. This method offers degrees of freedom as the dimensions and positions of these doped areas can be chosen to obtain the best performances. In this study, four filters were simulated and fabricated to spotlight different possibilities for the dimensions and positions of the ScDDA to control the low- or high-frequency transmission zero of the filters. The simulations were in very good agreement with the measured results. All the filters present insertion losses lower than 2 dB in the OFF and ON states, a great flexibility in the frequency choice, and good agility compared with the state of the art.
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