Low-Cost Houses for Self-Construction with Precast Wall Panels

The experience is described of a low-cost housing project developed in the past years in Costa Rica. suited for its particular climate and social conditions. The construction system provides precast prestressed concrete panels with thin cross-section, that can be moved and erected by few non specialized people. without the help of machinery. A full one-family house is easily built by the users with some help, The structure is made of bearing wall panels, clamped in a channel on foundation and linked together on top by a wooden rod. Wooden truss-beams support a light roof and realize a horizontal diaphragm, too, System's main features are: safety (dimensioned against wind and seismic actions), security (concrete walls); flexibility of lay-out and ease of adding rooms for enlarging the house; economy (self-construction); pleasing appearance. More than 1200 house's have been built with it, in the frame of a government granted program

Design and Realization of a MEMS Tunable Reflectarray for mm-Wave Imaging Application

Electronic beam scanning reflectarrays represent a very interesting solution to obtain reconfigurable antennas at mm-wave frequencies. The potentialities of such systems could be further increased in terms of costs and performance by employing MEMS devices. In this paper we present the design and the simulated results of a two-layer MEMS tuneable reflectarray. This antenna is designed for outdoor passive mm-waves imaging applications (35 GHz). The target is to realize a low cost, fast, small and light antenna system to be implemented in portable devices. The manufacturing of the prototype is on the way at the ITC-irst (Trento – IT) laboratories

Combined Liquid Crystal and MEMS Phase Shifter: Preliminary Measurement Results

This paper presents preliminary measurement results of a reflection phase shifter realized in a hybrid MEMS and Liquid Crystal technology. The MEMS switch part of the phase shifter is undesirably affected by Liquid Crystal, leading to a higher actuation voltage and the absence of a sudden switching operation. Nevertheless, measurements of the LC filled MEMS switch could achieve the desired 180° phase shift

MEMS and combined MEMS/LC technology for mm-wave Electronic Scanning

This paper proposes two innovative solutions for the exploitation of MEMS and Liquid Crystal (LC) technology in mm-wave electronic scanning reflectarrays: a MEMS-only approach, where the switches are used to obtain reconfigurable elementary cells with 1-bit of phase resolution and a LC/MEMS combined solution, able to provide a continuous phaseshift up to 180°

Combined Liquid Crystal and MEMS Phase Shifter: Preliminary Measurement Results

This paper presents preliminary measurement results of a reflection phase shifter realized in a hybrid MEMS and Liquid Crystal technology. The MEMS switch part of the phase shifter is undesirably affected by Liquid Crystal, leading to a higher actuation voltage and the absence of a sudden switching operation. Nevertheless, measurements of the LC filled MEMS switch could achieve the desired 180° phase shift

MEMS and combined MEMS/LC technology for mm-wave Electronic Scanning Reflectarrays

This paper presents the most recent advances within ARASCOM project (MEMS & Liquid Crystal based’ Agile Reflectarray Antennas for Security & COMmunication). One of the objectives of the project is the exploitation of MEMS and Liquid Crystal (LC) technology in mm-wave electronic scanning reflectarrays. In particular two solutions have been investigated: a MEMS-only approach, where the switches are used to obtain reconfigurable elementary cells with 1-bit of phase resolution - an efficient method applicable in large antennas; and a LC/MEMS combined solution, where the LCs provide a continuous phase-shift up to 180° and a MEMS is used to add another 180° when necessary. Preliminary results validate the proposed approach and give indications for future steps