A microstrip transmission line to waveguide transmission line transition. A microstrip transmission line is separated from a ground plane by a dielectric therebetween. The microstrip transmission line terminates at a microstrip transmission line open circuit end. A waveguide channel having narrow dimension waveguide walls and a broad dimension base waveguide wall connected therebetween is provided. The waveguide channel has a waveguide short circuit wall located along the channel. The narrow dim...

A method and apparatus for calibrating an electronic compass of the type having a compass sensor, a calibration table and a display. A computer operating under program control is used to update the calibration table of the electronic compass in response to physical movement of at least the electronic compass sensor and an angular rate gyroscope through a 360 degree movement. A pointing device associated with the electronic compass is initially directed to a known landmark position and is also di...

A Schottky diode, and a method of making the same, which is fabricated on InP material and employs a Schottky layer including In.sub.x Al.sub.1-x As with x>0.6, or else including a chirped graded supperlattice in which successive periods of the superlattice contain progressively less GaInAs and progressively more AlInAs, the increase in AlInAs being terminated before the proportion of AlInAs within the last period (adjacent the anode metal) exceeds 80%. Such fabrication creates an InP-based S...

A method and apparatus for providing a high impedance structure or surface comprising at least one electrically conductive wire forming at least one elongate wire spiral, the at least one elongate wire spiral being defined by a plurality of spirals of said at least one wire, the spirals having a pitch and being spaced apart along a major axis of said elongate wire spiral; and an arrangement for varying the pitch of the spirals of said at least one wire to thereby tune the impedance of said tunea...

A method and apparatus for reconfiguring an antenna array by optical control of MEMS switches. A light source is provided to direct light to individual optically sensitive elements which control delivery of actuating bias voltage to the MEMS switches. The light source is preferably separated from the antenna array by a structure which conducts the controlling illumination but provides a high impedance electromagnetically reflective surface which reflects electromagnetic radiation over the antenn...

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 layer...

A directive antenna and method of directing a radio frequency wave received by and/or transmitted from the antenna. The antenna preferably includes a high impedance surface with a plurality of antenna elements disposed on said surface, a plurality of associated demodulators and power sensors and a switch. A Vivaldi Cloverleaf antenna is disclosed.

Several delta-sigma modulator circuits and a single quantizer provide analog-to-digital conversion for multiple frequency bands. A wideband mode is provided by coupling an analog signal to be digitized directly to a quantizer. Narrowband modes are provided by switching the analog signal to be digitized into one of several delta-sigma modulator circuits. Noise shaping and filtering by the delta-sigma modulator circuits result in improved signal-to-noise-and-distortion performance and increased re...

A multiple band reconfigurable reflecting antenna array and method for multiple band operation and beam steering. An array of dipole antennas is disposed on a multiple band high impedance surface. The antenna array is reconfigured by changing the length of the dipole elements, to thereby change the dipoles resonant frequency. At a given frequency band, small changes in dipole length allow to steer the reflected beam in the selected direction; whether large changes in dipole length permit to swit...

A method for fabrication of a solder bump, comprising applying preferably an insulating film, followed by applying a multilayer underbump metallization, a layer of a photoresist, and a thin layer of titanium on a substrate containing, preferably, III-V semiconductor circuits. The multilayer UBM pad, preferably comprising a 0.02 to 0.05 micrometer thick layer of titanium, a 0.5 to 1.0 micrometer thick layer of nickel and a 0.1 to 0.2 thick layer of gold. The protective film with the thickness of ...