Abstract: An interferometer in which the path length of the reference beam, measured in wavelengths, is continuously changing in sinusoidal fashion and the interference signal created by combining the measurement beam and the reference beam is processed in real time to obtain the physical distance along the measurement beam between the measured surface and a spatial reference frame such as the beam splitter. The processing involves analyzing the Fourier series of the intensity signal at one or more optical detectors in real time and using the time-domain multi-frequency harmonic signals to extract the phase information independently at each pixel position of one or more optical detectors and converting the phase information to distance information.

Abstract: A small area cascode FET structure capable of operating at mm-wave frequenices cascades a common-source (CS) FET with a common gate (CG) FET, in a smaller physical area than conventional cascode FET structures. The small area of the cascode FET structure is partially achieved by using small source via grounds, requiring a thin gallium arsenide substrate (typically between 50 and 70 microns thick). The overall cascode area is reduced further, by having the two FETs share a common node. This common node is the output drain manifold of the CS FET, which is also an input source finger of the CG FET. In addition, small via grounds within the MIM capacitors and CS FET, which provide the ground connection to the gate manifolds of the CG FET, further reduce circuit area. Advantageously, the small area cascode FET can be applied to many different MMICs to reduce MMIC area requirements and cost.

Abstract: An improved method of and apparatus for real-time continual nanometer scale position measurement by beam probing as by laser beams and the like, both fixed and oscillating or scanning, over an atomic and other undulating surface such as gratings or the like, relatively moving with respect to the probing beams; and providing, where desired, increased detection speeds, improved positioning sensing response, freedom from or relaxed requirements of strict control on probing oscillation amplitude, and multi-dimensional position measurement with focused beam probes and the like.

Abstract: A wideband distributed or feedback amplifier monolithic microwave integrated circuit (MMIC) is disclosed that contains an integrated group delay equalizer circuit to compensate for the group delay variation of the amplifier circuitry. The MMIC amplifier is capable of achieving a predicted constant group delay with little variation over a wide frequency range. In addition, the group delay equalizer circuit enables the amplifier to achieve flat (constant) gain over a wide bandwidth, while maintaining constant group delay. Furthermore, the group delay equalizer circuitry requires only a small portion of the total MMIC area.

Abstract: A small area cascode FET structure capable of operating at mm-wave frequenices cascades a common-source (CS) FET with a common gate (CG) FET, in a smaller physical area than conventional cascode FET structures. The small area of the cascode FET structure is partially achieved by using small source via grounds, requiring a thin gallium arsenide substrate (typically between 50 and 70 microns thick). The overall cascode area is reduced further, by having the two FETs share a common node. This common node is the output drain manifold of the CS FET, which is also an input source finger of the CG FET. In addition, small via grounds within the MIM capacitors and CS FET, which provide the ground connection to the gate manifolds of the CG FET, further reduce circuit area. Advantageously, the small area cascode FET can be applied to many different MMICs to reduce MMIC area requirements and cost.

Abstract: A small aspect ratio, high power MMIC amplifier is disclosed. The small aspect ratio MMIC amplifier is capable of achieving the same power levels as conventional power amplifier designs, but with an aspect ratio of near 1:1, versus 4:1 of conventional power amplifiers. The small aspect ratio MMIC amplifier layout uses two different types of FETs, with all gate fingers of both types of FETs running in the same direction. One type of FET is a conventional FET, in which the gate stripes run parallel to the direction of the output. In the conventional FET, the gate manifold and the drain manifold both generally extend in the x-direction (parallel to each other). The other type of FET has gate fingers that run perpendicular to the direction of the output. In this other type of FET, the gate manifold generally extends in the x-direction, while the drain manifold generally extends in the y-direction (perpendicular to each other).

Abstract: A high frequency filter design for the GHz frequency range is provided. The high frequency filter comprises at least a microstrip design that incorporates both transverse and lateral couplings between the filters resonators. The high frequency filter further incorporates an opened or fully enclosed enclosure over the strip line or microstrip circuitry and may be manufactured on a relatively thick dielectric substrate having a thickness that is greater than about a twentieth of the filter's band-pass wavelength in the dielectric substrate. The high frequency filter design provides a small, easily reproducible filter design better than prior art microstrip filters.