Coplanar waveguide feeds for phased array antennas

The design and performance is presented of the following Coplanar Waveguides (CPW) microwave distribution networks for linear as well as circularly polarized microstrip patches and dipole arrays: (1) CPW/Microstrip Line feed; (2) CPW/Balanced Stripline feed; (3) CPW/Slotline feed; (4) Grounded CPW/Balanced coplanar stripline feed; and (5) CPW/Slot coupled feed. Typical measured radiation patterns are presented, and their relative advantages and disadvantages are compared

Space Power Amplification with Active Linearly Tapered Slot Antenna Array

A space power amplifier composed of active linearly tapered slot antennas (LTSA's) has been demonstrated and shown to have a gain of 30 dB at 20 GHz. In each of the antenna elements, a GaAs monolithic microwave integrated circuit (MMIC) three-stage power amplifier is integrated with two LTSA's. The LTSA and the MMIC power amplifier has a gain of 11 dB and power added efficiency of 14 percent respectively. The design is suitable for constructing a large array using monolithic integration techniques

Planar dielectric resonator stabilized HEMT oscillator integrated with CPW/aperture coupled patch antenna

A new design of an active antenna with a dielectric resonator stabilized high electron mobility transistor (HEMT) oscillator (DRO) and an aperture-coupled patch antenna is reported. The circuit is fabricated using coplanar waveguide (CPW) with the oscillator and the antenna on opposite sides of the substrate. The active antenna was demonstrated at 7.6 GHz; however, the design can be scaled to higher frequencies. Excellent oscillator characteristics and radiation patterns were obtained

Native American Students: Perceptions of Lived Experiences Attending a Small Predominantly White University in the Upper Midwest

The purpose of this qualitative study was to better understand the lived experiences of Native American students when studying on a predominantly white campus at a small university in the Upper Midwest. Using a phenomenological approach, the researcher interviewed each of the eight participants for one hour, although there were two interviews that took longer. Two participants agreed to meet for a second interview and, again, the time taken was approximately one hour. The resulting audio-recorded interviews were then transcribed, coded, and analyzed. Three themes emerged from the analysis of the data. Theme One: Participants depended on the support of home, the university, and especially the Native American Cultural Center, to help ease the culture shock of being a minority student in an alien environment. The paramount issue involved creating a new social support system, resulting in them seeking each other out or else committing themselves to strenuous commuting programs between university and home. It helped if professors took the time to understand their academic and cultural needs. Theme Two: With continued contact with the campus society, the participants gained more confidence in the white culture, and were finding their relationship with their home and culture was evolving. They expressed a desire for a multicultural society without prejudice, but remained adamant about maintaining their own culture. They tell each other not to quit, that it was probably worse back on the reservation. Theme Three: Assimilation was expressed as a negative option. Culture was seen as important and the goals expressed were educational success and returning to the reservations to help their people. Many plan on pursuing further education by attending graduate school. They had chosen to live in another environment but the commitment to their culture became stronger over time. The final assertion that emerged from this study was: Effective support of the cultural identity of Native American students studying on a predominantly white campus, by their family and the administration of the university, contributes to the retention and success of these students

Advances in Theory and Methodology

Section Introductio

Rosy Cheeks

Illustration of woman within frame surrounded by roseshttps://scholarsjunction.msstate.edu/cht-sheet-music/12641/thumbnail.jp

Microwave characterization of slotline on high resistivity silicon for antenna feed network

Conventional silicon wafers have low resistivity and consequently unacceptably high value of dielectric attenuation constant. Microwave circuits for phased array antenna systems fabricated on these wafers therefore have low efficiency. By choosing a silicon substrate with sufficiently high resistivity it is possible to make the dielectric attenuation constant of the interconnecting microwave transmission lines approach those of GaAs or InP. In order for this to be possible, the transmission lines must be characterized. In this presentation, the effective dielectric constant (epsilon sub eff) and attenuation constant (alpha) of a slotline on high resistivity (5000 to 10 000 ohm-cm) silicon wafer will be discussed. The epsilon sub eff and alpha are determined from the measured resonant frequencies and the corresponding insertion loss of a slotline ring resonator. The results for slotline will be compared with microstrip line and coplanar waveguide