Metal contact RF MEMS switch circuit elements have been developed to be used as building blocks for wideband signal routing. A switch element can have up to four switches fabricated monolithically on a single GaAs chip. More complicated switch circuits can be constructed by assembling multiple basic switch elements on a hybrid RF interconnection printed circuit board. In this paper, two basic types of switch functions are presented, single-pole multiple-throw switch elements and matrix switch elements. Measured insertion loss and isolation performances of these circuits are presented.

By covering a metal ground plane with a periodic surface texture, we can alter its electromagnetic properties. The impedance of this metasurface can be modeled as a parallel resonant circuit, with sheet inductance L, and sheet capacitance C. The reflection phase varies with frequency from +/spl pi/ to -/spl pi/, and crosses through 0 at the LC resonance frequency, where the surface behaves as an artificial magnetic conductor. By incorporating varactor diodes into the texture, we have built a tunable impedance surface, in which an applied bias voltage controls the resonance frequency, and the reflection phase. We can program the surface to create a tunable phase gradient, which can electronically steer a reflected beam over +/- 40/spl deg/ in two dimensions, for both polarizations. We have also found that this type of resonant surface texture can provide greater bandwidth than conventional reflectarray structures. This new electronically steerable reflector offers a low-cost alternative to a conventional phased array.

Une antenne reseau souple comprend une pluralite de couches en metal mince ainsi qu'un milieu isolant souple agence sous la forme d'un sandwich de couches. Chaque couche du sandwich est configuree selon les necessites pour definir: (i) des segments d'antenne configures dans une des couches metalliques, (ii) un reseau d'elements superieurs metalliques formes dans une couche espacee des segments d'antenne, le reseau d'elements superieurs metalliques etant configure dans une autre couche metallique, (iii) un reseau de terre metallique forme dans une couche espacee du reseau d'elements metalliques superieurs, le reseau de terre metallique ayant ete forme a partir d'encore une autre couche metallique, (iv) des elements inductifs couplant chacun des elements superieurs dans le reseau d'elements superieurs metalliques audit reseau de terre. Un reseau de commutateur commande a distance est prevu pour coupler ensemble des segments d'antenne selectionnes.

Reconfigurable aperture antenna technology has been enabled by the advent of RF MEMS switches. Typical measured insertion losses of less than 0.25 dB up to 40 GHz with superb broadband isolation means that reconfiguration of the antenna for multi-band operation can now occur with a few MEMS switches rather than multiple PIN diode or FET switch circuits. In this paper, we describe a reflectarray antenna approach that can perform true time delay beam steering by using cascaded RF MEMS switches/coplanar strip transmission line sections. Measured RF MEMS switch characteristics in coplanar strip transmission lines are presented and the modeled reflected phase of five cascaded switch/transmission line sections is presented.