摘要:
A micro-electromechanical system (MEMS) switch formed on a substrate, the switch comprising a transmission line formed on the substrate, a substrate electrostatic plate formed on the substrate, and an actuating portion. The actuating portion comprises a cantilever anchor formed on the substrate and a cantilevered actuator arm extending from the cantilever anchor. Attraction of the actuator arm toward the substrate brings an electrical contact into engagement with the portions of the transmission line separated by a gap, thus bridging the transmission line gap and closing the circuit. In order to maximize electrical isolation between the transmission line and the electrical contact in an OFF-state while maintaining a low actuation voltage, the actuator arm is bent such that the minimum separation distance between the transmission line and the electrical contact is equal to or greater than the maximum separation distance between the substrate electrostatic plate and arm electrostatic plate.
摘要:
A flexible antenna array comprises a plurality of layers of thin metal and a flexible insulating medium arranged as a sandwich of layers. Each layer of the sandwich is patterned as needed to define: (i) antenna segments patterned in one of the metal layers, (ii) an array of metallic top elements formed in a layer spaced from the the antenna segments, the array of metallic top elements being patterned in another metal layer, (iii) a metallic ground plane formed in a layer spaced from the array of metallic top elements, the metallic ground plane having been formed from still another metal layer, and (iv) inductive elements coupling each of the top elements in the array of metallic top elements with said ground plan. An array of remotely controlled switches are provided for coupling selected ones of said antenna segments together.
摘要:
Apparatus for a micro-electro-mechanical switch that provides single pole, double throw switching action. The switch comprises a single RF input line and two RF output lines. The switch additionally comprises two armatures, each mechanically connected to a substrate at one end and having a conducting transmission line at the other end with a suspended biasing electrode located on top of or within a structural layer of the armature. Each conducting transmission line has conducting dimples that protrude beyond the bottom of the armature carrying the conducting transmission line. Closure of an armature causes the dimples of the corresponding conducting transmission line to mechanically and electrically engage the RF input line and the corresponding RF output line, thus directing RF energy from the RF input line to the selected RF output line.
摘要:
A microelectromechanical (MEM) switch is fabricated inexpensively by using processing steps which are standard for fabricating multiple metal layer integrated circuits, such as CMOS. The exact steps may be adjusted to be compatible with the process of a particular foundry, resulting in a device which is both low cost and readily integrable with other circuits. The processing steps include making contacts for the MEM switch from metal plugs which are ordinarily used as vias to connect metal layers which are separated by a dielectric layer. Such contact vias are formed on either side of a sacrificial metallization area, and then the interconnect metallization is removed from between the contact vias, leaving them separated. Dielectric surrounding the contacts is etched back so that they protrude toward each other. Thus, when the contacts are moved toward each other by actuating the MEM switch, they connect firmly without obstruction. Tungsten is typically used to form vias in CMOS processes, and it makes an excellent contact material, but other via metals may also be employed as contacts. Interconnect metallization may be employed for other structural and interconnect needs of the MEM switch, and is preferably standard for the foundry and process used. Various metals and dielectric materials may be used to create the switches, but in a preferred embodiment the interconnect metal layers are aluminum and the dielectric material is SiO2, materials which are fully compatible with standard four-layer CMOS fabrication processes.
摘要:
A microelectromechanical (MEM) switch is fabricated inexpensively by using processing steps which are standard for fabricating multiple metal layer integrated circuits, such as CMOS. The exact steps may be adjusted to be compatible with the process of a particular foundry, resulting in a device which is both low cost and readily integrable with other circuits. The processing steps include making contacts for the MEM switch from metal plugs which are ordinarily used as vias to connect metal layers which are separated by a dielectric layer. Such contact vias are formed on either side of a sacrificial metallization area, and then the interconnect metallization is removed from between the contact vias, leaving them separated. Dielectric surrounding the contacts is etched back so that they protrude toward each other. Thus, when the contacts are moved toward each other by actuating the MEM switch, they connect firmly without obstruction. Tungsten is typically used to form vias in CMOS processes, and it makes an excellent contact material, but other via metals may also be employed as contacts. Interconnect metallization may be employed for other structural and interconnect needs of the MEM switch, and is preferably standard for the foundry and process used. Various metals and dielectric materials may be used to create the switches, but in a preferred embodiment the interconnect metal layers are aluminum and the dielectric material is SiO2, materials which are fully compatible with standard four-layer CMOS fabrication processes.
摘要:
Method and apparatus for actuating switches in a reconfigurable antenna array. Micro electro-mechanical system (MEMS) switches span gaps between antenna elements disposed on an antenna substrate. An integrated optic waveguide network which directs optical energy towards the MEMS switches is contained in a superstrate disposed above the antenna elements and substrate. The MEMS switches are formed on a semi-insulating substrate. When illuminated, the resistance of the semi-insulating substrate is lowered so as the reduce the resistance between the control contacts. The antenna array is reconfigured by directing optical energy to the photo-voltaic cells connected to selected MEMS switches to close those MEMS switches, thereby electrically connecting selected antenna elements and by directing optical energy to the semi-insulating substrate of selected MEMS switches to open those MEMS switches, thereby electrically disconnecting selected antenna elements.
摘要:
A photodetector is fabricated in a multilayer structure having a semi-insulating InP substrate, an n+ InP contact layer overlying the InP substrate, an undoped InGaAs absorbing layer overlying the n+ InP contact layer, and a p+ doped InGaAs layer overlying the undoped InGaAs absorbing layer. A gold-beryllium p-contact dot is deposited onto the p+ doped InGaAs layer of the multilayer structure. A mesa structure is etched with a citric acid-based etchant into the multilayer structure. The mesa structure includes the metal p-contact dot, the p+ doped InGaAs layer, and the undoped InGaAs absorbing layer. The n+ InP contact layer is patterned, and a passive metallic n-contact layer is deposited onto the patterned n+ InP contact layer. A polyimide insulator layer overlying a portion of the structure is deposited and patterned, so that the polyimide insulator layer does not cover the passive metal p-contact dot and the metallic n-contact layer. The patterned organic polymer insulator layer is cured and the device is passivated by heating it in a nitrogen atmosphere. Thick metallic gold contract traces are deposited, with one trace extending to the gold-beryllium p-contact dot and the other trace extending to the metallic n-contact layer.
摘要:
An optically controlled micro-electromechanical (MEM) switch is described which desirably utilizes photoconductive properties of a semiconductive substrate upon which MEM switches are fabricated. In one embodiment the bias voltage provided for actuation of the switch is altered by illuminating an optoelectric portion of the switch to deactivate the switch. In an alternative embodiment, a photovoltaic device provides voltage to actuate the switch without any bias lines at all. Due to the hysteresis of the electromechanical switching as a function of applied voltage, only modest variation of voltage applied to the switch is necessary to cause the switch to open or close sharply under optical control.
摘要:
A method and apparatus for comparing a force to a signal, or comparing two signals, through mechanical movement of capacitive plates in a transducer. The transducer plates are separated by d, which in one embodiment is preferably a linear function of a pressure or force F. In that embodiment, application of a signal i(t+&tgr;) to the plates will cause a voltage representing a correlation between F and i to appear between the plates. In another embodiment, instead of an external mechanical force or pressure, an electrical signal V related to a signal S may drive the transducer plates to achieve a voltage indicating a correlation between S and the signal input i(t+&tgr;). Transducers to practice the invention may be microelectromechanical devices fabricated using integrated circuit techniques to permit small size and low cost.
摘要:
An optically controlled micro-electromechanical (MEM) switch is described which desirably utilizes photoconductive properties of a semiconductive substrate upon which MEM switches are fabricated. In one embodiment the bias voltage provided for actuation of the switch is altered by illuminating an optoelectric portion of the switch to deactivate the switch. In an alternative embodiment, a photovoltaic device provides voltage to actuate the switch without any bias lines at all. Due to the hysteresis of the electromechanical switching as a function of applied voltage, only modest variation of voltage applied to the switch is necessary to cause the switch to open or close sharply under optical control.