System concepts for millimeter-wave personal communication systems and the advantages of millimeter-wave band usage are briefly described. Demonstration of broadband millimeter-wave subcarrier transmission concepts over fiber-optic links is performed. Several fiber-optic link architectures, including one using a combination of direct laser modulation and indirect (external) optical modulation, are outlined with respect to signal transmission at millimeter-wave frequencies. Several configurations are experimentally investigated using 70-MHz, 300-MHz, and 26-GHz subcarriers which transmit either FM or QPSK data signals. Additionally, the use of optical MMIC technology, which can result in the design of compact and cost-effective optical receivers, is described with respect to personal communication radio base station equipment. MMIC HEMTs operating as photodetectors are newly characterized in terms of digital and analog signal reception with excellent performance being observed. >

Millimeter-wave fiber optics systems for personal radio communication

A communications system includes at least one low earth orbit first satellite (10), at least one second satellite (11) in other than a low earth orbit, and a ground segment (12) that includes a plurality of user transceivers (78, 80, 82, 84) and at least one gateway (76) coupled to a publicly-accessible terrestrial communications system, such as a PSTN and/or a fiber optic network. The first satellite includes a first transceiver for communication with the at least one gateway, a second transceiver for communication with at least one user transceiver, and a third transceiver for communication with the at least one second satellite. The first, second and third transceivers are switchably coupled together on-board the first satellite by on-board processors and a switching matrix for relaying a user communication between the at least one gateway and the at least one user transceiver via the at least one second satellite. The plurality of user transceivers can include a plurality of data processors which are interconnected into a network through the at least one first satellite. This network can be considered as a virtual network, and can have a mesh, star, or other topology. The user transceivers can be adapted to transmit and receive direct sequence, code division/multiple access communications. Transmission of signals to and from the user transceivers is accomplished by spreading a digital data stream (e.g., voice, data, image, video) with assigned spreading codes.

Interactive fixed and mobile satellite network

A structure and method for producing mask-configured integrated circuits which are pin compatible substitutes for user-configured logic arrays is disclosed. Mask-defined routing lines having resistive/capacitive characteristics simulating those of user-configurable routing paths in the user-configurable logic array are used in the mask-defined substitutes to replace the user-configurable routing paths. Scan testing networks are formed in the metal-configured substitutes to test the operability of logical function blocks formed on such chips. The scan testing networks comprise a plurality of test blocks each including three field effect pass transistors formed of four adjacent diffusion regions. Proper connection of the gates of these pass transistors to control lines controlling the transistors is tested by transmitting alternating high/low signals through serial conduction paths including the gate electrodes of these transistors.

Structure and method for producing mask-programmed integrated circuits which are pin compatible substitutes for memory-configured logic arrays

We investigate the generation of signals using pulsed semiconductor lasers for application in millimeter-wave (mm-wave) wireless links. The generation of mm wave harmonic frequencies in both mode-locked and gain-switched lasers is considered and a method to generate mm-wave modulated optical signals with modulation depths approaching 100% is implemented. The technique uses optical filtering to select only two optical modes in the pulsed laser spectrum that beat together in a highspeed photodiode. The application of this method to the feeding of mm-wave wireless links incorporating microstrip patch antennas is demonstrated. These optically fed links have application in indoor wireless LAN's and optical fiber microcellular systems. >

Signal generation using pulsed semiconductor lasers for application in millimeter-wave wireless links

Superconducting microstrip ring resonators operating at 35 GHz have been fabricated from laser ablated YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) films on lanthanum aluminate substrates. The circuits consisted of superconducting strips over normal metal ground planes. The circuits are measured from 20 K to 90 K and with microwave input powers ranging from 0.25 mW to 10 mW. The superconducting resonators show significant improvement in Q over identical gold resonators at 20 K, but only marginal improvement at 77 K. No variation in the superconductor performance is observed with varying input power. The lowest microwave surface resistance of the superconductors at 77 K is 9 m Omega . The change in the resonant frequency with temperature is analyzed and a value for the penetration depth computed. Double resonances were observed in some superconducting ring resonators and an explanation is advanced. Factors limiting millimeter-wave high-temperature superconductor circuits are explored and potential performance levels calculated based on current reported values for high-temperature superconductor surface resistances. >

YBCO superconducting ring resonators at millimeter-wave frequencies

Low-loss fiber-optic links are designed for distribution of data and the frequency reference in large-aperture phased-array antennas based on the transmit/receive-level data mixing architecture. In particular, design aspects of a fiber-optic link satisfying the distribution requirements of satellite data traffic are presented. The design is addressed in terms of reactively matched optical transmitter and receiver modules. Analog and digital characterization of a 50-m fiber-optic link realized using these modules indicates the applicability of this architecture as the only viable alternative for distribution of data signals inside a satellite at present. It is demonstrated that the design of a reactive matching modules enhances the link performance. A dynamic range of 88 dB/MHz was measured for analog data over 500-1000-MHz bandwidth. >

High-speed fiber-optic links for distribution of satellite traffic

An MMIC test fixture includes a bias module having spring-loaded contacts which electrically engage pads on a chip carrier disposed in a recess of a base member RF energy is applied to and passed from the chip carrier by chamfered edges of ridges in the waveguide passages of housings which are removably attached to the base member "Thru", "Delay" and "Short" calibration standards having dimensions identical to those of the chip carrier assure accuracy and reliability of the test The MMIC chip fits in an opening in the chip carrier with the boundaries of the MMIC lying on movable reference planes thereby establishing accuracy and flexibility

Universal nondestructive MM-wave integrated circuit test fixture

In this paper, electromagnetic (EM) leakage and spurious resonances in a K/Ka-Band (18-40 GHz) MMIC hermetic package designed for a phase shifter chip are studied using the finite element method (FEM) and the numerical simulation results are compared with the measured data. Both the measured and calculated data indicate several spurious resonances in the 18-24 GHz region and the origin of this phenomenon is identified by virtue of the modeling capability of the FEM. Moreover, the effect of dc bias lines, bond wires, shielding, and the asymmetry of the package on electrical performance are closely examined. In addition, the effect of adding a resistive coating to the inside surface of the package lid and also the use of dielectric packaging materials with very high loss tangent are studied in view of the suppression of the spurious resonances. Finally, design guidelines for the improved package are presented.

Experimental and theoretical study of parasitic leakage/resonance in a K/Ka-band MMIC package

NASA Glenn Research Center (GRC), in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the Federal Aviation Administration (FAA) and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the GRC prototype CNPC architecture as a demonstration platform. The proposed security controls were integrated into the GRC flight test system aboard our S-3B Viking surrogate aircraft and several network tests were conducted during a flight on November 15th, 2014 to determine whether the controls were working properly within the flight environment. The flight test was also the first to integrate Robust Header Compression (ROHC) as a means of reducing the additional overhead introduced by the security controls and Mobile IPv6. The effort demonstrated the complete end-to-end secure CNPC link in a relevant flight environment.

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Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

The microwave characteristics at 18 and 20 GHz of submicron-gate indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFETs) for high output power density applications are presented. InP power MISFETs were fabricated with 0.7 mu m gate lengths, 0.2 mm gate widths, and drain-source spacings of 2, 3 and 5 mu m. The output power density was investigated as a function of drain-source spacing. The best output power density and gain were obtained for drain-source spacings of 3 mu m. At 18 GHz output power densities of 1.59 W/mm with a gain of 3.47 dB and a power-added efficiency of 20.0% were obtained for a drain-source spacing of 3 mu m. At 20 GHz output power densities of 1.20 W/mm with a gain of 3.17 dB and a power-added efficiency of 13.6% were obtained for a drain-source spacing of 3 mu m. >

/pdf/submicron-gate-inp-power-misfet-s-with-improved-output-power-4gswz35obr.pdf

Kurt A. Shalkhauser

Papers

High-speed fiber-optic links for distribution of satellite traffic

Universal nondestructive MM-wave integrated circuit test fixture

Experimental and theoretical study of parasitic leakage/resonance in a K/Ka-band MMIC package

Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

Submicron-gate InP power MISFET's with improved output power density at 18 and 20 GHz