In this thesis, we theoretically investigate optimum configurations of high conversion efficiency and gain-flattened L-band (1570-1600 nm) erbium-doped fiber amplifier (EDFA) by employing the 1480 nm and 980 nm bi-directional pumping configuration. The design criterion of L-band EDFA is to achieve highest channel output power while keeping the differential channel gain to be ¡Õ0.7 dB among 32 channels with low channel noise figure of ¡Õ6 dB. The nine L-band EDFA configurations are examined and compared. These configurations considered include the dual-forward, dual-backward, and different bi-directional pumping schemes, each with and without the midway optical isolator. Among all configurations, we find that the pump-pass case in forward-and-backward pumping scheme by employing the 1480 nm pumping wavelength is the best configuration to offer the highest channel output power with good channel gain uniformity and moderate low noise figure. Then we verified the simulation results through experiments. We also theoretically investigate gain-flattened C-band (1530-1560 nm) EDFA. Using L-band and C-band EDFAs in parallel, we can greatly expand the amplification wavelength region.

ABSTRACT In this thesis, we investigate the amplification characteristics of gain-flattened L-band (1570-1600 nm) erbium-doped fiber amplifier (EDFA) by employing the 1480 nm bi-directional pumping configuration. L-Band EDFAs are attractive because the use of L-band and C-band (1530-1560 nm) EDFAs in parallel greatly expands the amplification wavelength region. We adjusted the length of erbium-doped fiber (EDF) to achieve the flat amplification characteristics in the 1573-1600 nm wavelength region without using gain equalizers. The L-band EDFA exhibited a signal gain of 23 dB with good uniformity (less than 1 dB) and a noise figure of 6.9 dB for a 1580 nm signal of 16-channel WDM system. We also used the simulation tools to investigate the characteristics of L-band EDFA with the same configuration. The simulation results quite agree with the experimental data.

<p> The subject of this thesis is the design, fabrication and comparative testing of two prototype L-band ferrite digital latching phase shifters. One phaser is a variation of a design published by G.T. Roome and H.A. Hair, "Thin Ferrite Devices for Microwave Integrated Circuits", IEEE Trans. Microwave Theory Tech, vol. MTT-16 pp. 411-420, July 1968. The second design is original and is experimentally and theoretical compared to the first phaser. A comparative study was made because of technological difficulties in making these devices. Insertion losses of 2dB and an order of magnitude less than possible phase shift occurred because of inadequate production facilities. Thus, the comparative study gave a common mode error to the published device and the new device.</p> <p> Also, the theory of ferrite microwave phasers and a discussion of a particular system application which prompted this study are included in this thesis.</p> / Thesis / Master of Engineering (MEngr)

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In a study sponsored by the Air Force Flight Test Center at Edwards AFB, California, Toyon Research Corporation, Goleta, California, demonstrated that shaped pattern antennas could be used to mitigate interference caused by telemetry signals on GPS systems. Using a technique for fixed reception pattern antenna (FRPA) design, Toyon built and tested a GPS antenna that minimizes reception of telemetry signals from a known location.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Meeting the filtering requirements for telemetry transmitters and receivers can be challenging. Telemetry systems use filters to eliminate unwanted spurious or mixing products. The use of tunable microwave filters for both L and S Band can improve filter selectivity and provide low insertion losses in the filter passband. Along with meeting specifications, these microwave filters with the ability to tune an octave, reduce size and cost by the reduction of multiple, fixed-frequency filters. As size, weight and power are often a concern with aeronautical telemetry systems, this paper will demonstrate that microstrip tunable filters can be small in size and use minimal power. Telemetry transmitters are subject to difficult spurious emission and interference specifications and require selective filters to eliminate spurious signals before the final amplification. Telemetry receivers on the other hand are subject to intense Image and Local Oscillator (LO) rejection requirements and demand low insertion loss for front-end filtering. Low insertion loss filtering before the Low Noise Amplifier (LNA) circuit limits degradation to the system noise figure (NF). By using different filter topologies and state-of-the-art, high-Q varactor diodes, tunable microwave filters can be optimized for two different functions. The two functions emphasize either low insertion loss or selectivity. An important design consideration with tunable filters, when compared to typical fixed frequency filters, is the degraded intermodulation performance. This is largely due to the non-linear behavior of the varactor diodes. This paper describes the benefits and limitations of microwave tunable filter architectures suitable for both aeronautical telemetry transmitters and telemetry receivers. Information on the computer modeling of varactor diodes will be covered as a critical part of the design. Potential design considerations for microwave tunable filters will also be covered. Through the use of simulation software and filter prototypes, this paper presents dramatically improved filter performance applicable to telemetry transmitters and receivers.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / This paper reports the analysis of L-band channel sounding experiments conducted along the flight line at Cairns Army Airfield, Ft. Rucker, Alabama. Propagation data from multiple antennas on a helicopter to multiple receiving antennas on the ground are used to compute power delay profiles. Analysis of the results reveals delay spreads of the multipath channels between 200 ns and 400 ns, with the longer delay spreads resulting when using a receive antenna with lower gain and higher sidelobe levels. The data also shows that on average, diversity signaling from three aircraft-mounted antennas can lead to gains in signal-to-noise ratio of approximately 13 dB, with the gain dependent on the multipath characteristics observed by the ground antenna.

The SMAPVEX12 (Soil Moisture Active/Passive Validation Experiment 2012) was carried out over the summer of 2012 in Manitoba, Canada. The goal of the project was to improve the accuracy of satellite-based remote sensing of soil moisture. Data were gathered during a 42-day field campaign with surface measurements on 55 different agricultural fields in south-central Manitoba. The extended duration of the campaign, contrast in soil textures, and variety of crop types over the study region provided an excellent range of soil moisture and vegetation conditions. The study fields ranged from bare to fully vegetated, with volumetric soil moisture levels spanning a range of almost 50%. Remotely sensed data were collected on 17 days by aircraft at 1.4 Ghz with a microwave radiometer at two different resolutions. Observed brightness temperatures from the radiometer showed a typical inverse relationship to the near simultaneous soil moisture measurements from the field. Field-by-field relationships using all sampling dates with both soil and emissivity data were all shown to be significant with the exception of two of the pasture fields and a soybean field. Linear regressions across multiple fields and by flight lines also had statistically significant slopes. The significance of all these relationships improved with the removal of pasture fields from the analysis. On most fields, the sensitivity (slope) of the relationship and correlation coefficient (R2) between emissivity and observed soil moisture increased when vegetation and roughness effects were taken into account. The b parameter that relates vegetation water content to optical depth in the tau-omega model was optimized using the collective slope and R2 values of the individual fields. A b parameter value of 0.06 for horizontal polarization and 0.13 for vertical polarization were found to be optimal across the range of all fields in this analysis. / May 2016

In this thesis, we investigate the single-pumped L-band (1570-1610 nm) amplified spontaneous emission fiber source by employing 1480 nm single pumping configuration. Using the 1480 nm-pumped laser, we chose the adequate fiber length and adjusted the pump power to optimize the characteristics of the ASE source. The characteristics are experimentally examined and compared in terms of the output power, mean wavelength, spectral linewidth, and pumping conversion efficiency in four configurations with single-pass forward (SPF), single-pass backward (SPB), double-pass forward (DPF), and double-pass backward (DPB) structures. Among them, the DPF configuration with low mirror reflectance of 8% is the better one to be an L-band ASE fiber source with output power of 13.8 mW, mean wavelength of 1585.7 nm, spectral linewidth of 40.9 nm and pumping efficiency of 13.8%.

<p>I detta examensarbete presenteras två olika konstruktionslösningar för ett spegeldämpande filter till en heterodynmottagare för L-bandet. Båda filtren är uppbyggda av distribuerade element i mikrostripsteknik. Filtertyper som behandlas är combline med kapacitansdioder för avstämning samt filter med element av typen commensurate length transmissionsledning. Nödvändig teori om mikrostripteknik och distribuerade element behandlas. Konstruktionen av filtren beskrivs steg för steg från filterkrav till färdig mönsterlayout. Layouterna har simulerats med em™ simulatorprogram.</p>

I detta examensarbete presenteras två olika konstruktionslösningar för ett spegeldämpande filter till en heterodynmottagare för L-bandet. Båda filtren är uppbyggda av distribuerade element i mikrostripsteknik. Filtertyper som behandlas är combline med kapacitansdioder för avstämning samt filter med element av typen commensurate length transmissionsledning. Nödvändig teori om mikrostripteknik och distribuerade element behandlas. Konstruktionen av filtren beskrivs steg för steg från filterkrav till färdig mönsterlayout. Layouterna har simulerats med em™ simulatorprogram.