Limited phase deviation frequency multiplier phase modulator, appendix e final report
Limited phase deviation frequency multiplier phase modulator - application to radio frequency test console equipment
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Wide deviation phase modulator
Modulator produces phase-modulated waveform having high modulating linearity. Technique is inherently wideband with respect to carrier frequency and can operate over decade carrier frequency range without adjustments. Circuit performance is both mathematically predictable and highly reproducible.
Couch, R. H.↗
Advanced study of video signal processing in low signal to noise environments
A nonlinear analysis of a multifilter phase-lockloop (MPLL) by using the method of harmonic balance is presented. The particular MPLL considered has a low-pass filter and a band-pass filter in parallel. An analytic expression for the relationship between the input signal phase deviation and the phase error is determined for sinusoidal FM in the absence of noise. The expression is used to determine bounds on the proper operating region for the MPLL and to investigate the jump phenomenon previously observed. From these results the proper modulation index, modulating frequency, etc. used for the design of a MPLL are determined. Data for the loop unlock boundary obtained from the theoretical expression are compared to data obtained from analog computer simulations of the MPLL.
Carden, F.↗
Laser Interferometer Space Antenna (LISA) Far Field Phase Pattern
The Laser Interferometry Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer that will measure the changes in the distance of a five million kilometer arm to pico meter accuracies. Knowledge of the phase deviations from a spherical wave and what causes these deviations are needed considerations in (as a minimum) the design of the telescope and in determining pointing requirements. Here we present the far field phase deviations from a spherical wave for given Zernike aberrations and obscurations of the exit pupil.
Waluschka, Eugene↗
Laser Interferometer Space Antenna (LISA) Far Field Phase Patterns
The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer, which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. Knowledge of the phase deviations from a spherical wave and what causes these deviations are needed considerations in (as a minimum) the design of the telescope and in determining pointing requirements. Here we will present the far field phase deviations from a spherical wave for given Zernike aberrations of the exit pupil and discuss how these results affect the choice of a telescope design.
Waluschka, Eugene↗
Performance results of a 300-degree linear phase modulator for spaceborne communications applications
A phase modulator capable of large linear phase deviation, low loss, and wide band operation with good thermal stability was developed for deep space spacecraft transponder (DST) applications at X-band (8.415 GHz) and Ka-band (32 GHz) downlinks. The design uses a two-stage circulator-coupled reflection phase shifter with constant gamma hyperabrupt varactors and an efficient modulator driver circuit to obtain a phase deviation of +/-2.5 rad with better than 8 percent linearity. The measured insertion loss is 6.6 dB +/- 0.35 dB at 8415 MHz. Measured carrier and relative sideband amplitudes resulting from phase modulation by sine wave and square modulating functions agree well with the predicted results.
Mysoor, N. R.↗
Performance results of a 300-deg linear phase modulator for spaceborne communications applications
A phase modulator capable of large linear phase deviation, low loss, and wide band operation with good thermal stability was developed for deep space spacecraft transponder (DST) applications at X-band (8.415 GHz) and Ka-band (32 GHz) downlinks. The design uses a two-stage circulator-coupled reflection phase shifter with constant gamma hyperabrupt varactors and an efficient modulator driver circuit to obtain a phase deviation of +/- 2.5 rad with better than 8 percent linearity. The measured insertion loss is 6.6 dB +/- 0.35 dB at 8415 MHz. Measured carrier and relative sideband amplitudes resulting from phase modulation by sine wave and square modulating functions agree well with the predicted results.
Mysoor, Narayan R.↗
Phase linearity of the 914H coupled-cavity traveling wave tube
Tests of phase deviation from linearity were made on two 914H coupled-cavity traveling wave tubes (TWT). One tube had a voltage standing wave ratio (VSWR) of 2.4 and the other 1.4. The data showed that phase deviation is primarily a function of the amplitude and shape of the output VSWR. It was predicted that the low-VSWR tube would give a better system performance than the tube with a high VSWR. This prediction was confirmed by the Advanced Communications Technology Satellite (ACTS) system tests performed at the NASA Lewis Research Center. A possible improvement in the construction and stability of coupled-cavity TWT's is discussed.
Kavanagh, Frank E.↗
Design and analysis of a low-loss linear analog phase modulator for deep space spacecraft X-band transponder applications
This article summarizes the design concepts, analyses, and development of an X-band (8145 MHz) transponder low-loss linear phase modulator for deep space spacecraft applications. A single-section breadboard circulator-coupled reflection phase modulator has been analyzed, fabricated, and evaluated. A linear phase deviation of 92 deg with a linearity tolerance of +/- 8 percent was measured for this modulator from 8257 MHz to 8634 MHz over the temperature range -20 to 75 C. The measured insertion loss and the static delay variation with temperature were 2 +/- 0.3 dB and 0.16 psec/ C, respectively. Based on this design, cascaded sections have been modeled, and simulations were performed to provide an X-band deep space transponder (DST) phase modulator with +/- 2.5 radians (+/- 143 deg) of peak phase deviation to accommodate downlink signal modulation with composite telemetry data and ranging, with a deviation linearity tolerance of +/- 8 percent and insertion loss of less than 10 +/- 0.5 dB. A two-section phase modulator using constant gamma hyperabrupt varactors and an efficient modulator driver circuit was breadboarded. The measured results satisfy the DST phase-modulator requirements and show excellent agreement with the predicted results.
Mysoor, N. R.↗
Design and analysis of low-loss linear analog phase modulator for deep space spacecraft X-band transponder (DST) application
This paper summarizes the design concepts, analyses, and the development of an X-band transponder low-loss linear phase modulator for deep space spacecraft applications. A single section breadboard circulator-coupled reflection phase modulator has been analyzed, fabricated, and evaluated. Two- and three-cascaded sections have been modeled and simulations performed to provide an X-band DST phase modulator with +/- 2.5 radians of peak phase deviation to accommodate down-link signal modulation with composite telemetry data and ranging with a deviation linearity tolerance +/- 8 percent and insertion loss of less than 10 +/- 0.5 dB. A two-section phase modulator using constant gamma hyperabrupt varactors and an efficient modulator driver circuit was breadboarded. The measured results satisfy the DST phase modulator requirements, and excellent agreement with the predicted results.
Mysoor, Narayan R.↗
Wideband Linear Phase Modulator
Phase modulator for transmission in X band provides large phase deviation that remains nearly linear with voltage over relatively wide range. Operates with low loss over wide frequency band and with stable characteristics over wide temperature range. Phase modulator contains two varactor-diode phase shifters coupled via circulators. Separate drive circuit applies modulating voltages to varactor diodes. Modulation voltages vary in accordance with input to drive circuit.
Mysoor, Narayan R.↗
MMIC linear-phase and digital modulators for deep space spacecraft X-band transponder applications
The design concepts, analyses, and development of GaAs monolithic microwave integrated circuit (MMIC) linear-phase and digital modulators for the next generation of space-borne communications systems are summarized. The design approach uses a compact lumped element quadrature hybrid and Metal Semiconductor Field Effect Transistors (MESFET)-varactors to provide low loss and well-controlled phase performance for deep space transponder (DST) applications. The measured results of the MESFET-diode show a capacitance range of 2:1 under reverse bias, and a Q of 38 at 10 GHz. Three cascaded sections of hybrid-coupled reflection phase shifters were modeled and simulations performed to provide an X-band (8415 +/- 50 MHz) DST phase modulator with +/- 2.5 radians of peak phase deviation. The modulator will accommodate downlink signal modulation with composite telemetry and ranging data, with a deviation linearity tolerance of +/- 8 percent and insertion loss of less than 8 +/- 0.5 dB. The MMIC digital modulator is designed to provide greater than 10 Mb/s of bi-phase modulation at X-band.
Mysoor, Narayan R.↗
The use of satellite beacons for meteorological research
The use of microwave beacon transmissions from synchronous and near synchronous satellites is discussed as a means of measuring atmospheric absorption. It is suggested that, with a fixed angle of elevation of a synchronous satellite, complete diurnal coverage of the integrated absorption is available. In addition, with refined interferometric equipment, angle of arrival studies can be made and phase deviations measured.
Aarons, J.↗
Linearity optimization in a class of analog phase modulators
This paper examines the ultimate modulating linearity attainable with a phase modulation technique based on the linear addition of quadrature phase carrier signals which have been multiplied by precisely defined nonlinear transformations of the modulating signal. Optimum gain coefficients are derived and plotted to permit implementation of analog phase modulators capable of exceptionally good linearity of phase deviations as large as 5 radians.
Hearn, C. P.↗
Development of a class of antennas for space-based Navstar GPS applications
This paper describes the performance of several unique antenna/ground plane configurations currently being developed for the TOPEX satellite and which may also be used for improved ground station operation. These antennas are designed with the objective of achieving nearly hemispherical coverage with sharp pattern cutoff above the horizon together with uniform phase response over the entire coverage area. The most promising of these designs is a uniform choke ring approximately 2 lambda in diameter. The ground planes, when used with the Dorne-Margolin C246 antenna element, produce smooth pattern cutoff of the order of 0.25 dB per deg over 135 deg, excellent LCP rejection, and rms phase deviation of 5-5.7 deg. Other ground plane designs, including larger choke ring structures, slotted ground planes, and the use of absorber material, proved much less effective.
Tranquilla, J. M.↗
Miniature X-band GaAs MMIC analog and bi-phase modulators for spaceborne communications applications
The design concepts, analyses, and the development of GaAs monolithic microwave integrated circuit (MMIC) linear-phase and digital modulators for the next generation of spaceborne communications systems are summarized. The design approach uses a very compact lumped-element, quadrature hybrid, and MESFET-varactors to provide low-loss and well-controlled phase performance for deep-space transponder (DST) applications. The measured results of the MESFET-diode show a capacitance range of 2:1 under reverse bias, and a Q of 38 at 10 GHz. Three cascaded sections of hybrid-coupled reflection phase shifters have been modeled and simulations performed to provide an X-band (8415 +/- 50 MHz) DST phase modulator with +/-2.5 radians of peak phase deviation.
Mysoor, Narayan R.↗
Measuring Frequency Instability Of A Large Antenna
Frequency instability of antenna under test determined from measurement of phase deviation between outputs of two antennas. Fiber-optic system used to minimize spurious component of frequency instability contributed by propagation of signal from reference antenna to Allan-variance-measuring instrument. Intended primarily to reveal contributions of wind and air-temperature effects on antenna and beam-waveguide structures to overall frequency instabilities of received signals. Technique simpler, less expensive, potentially capable of providing instability data in shorter measuring times, and more precise.
Otoshi, Tom Y.↗
The MRIS feasibility study
The Microwave Reflectometer Ionization Sensor (MRIS) is an instrument being developed for use in detecting and ranging of electron density layers in the reentry plasma of a space transfer vehicle. The rationale for the selection of the Double Sideband Suppressed Carrier (DSBSC) system used in the feasibility study for the MRIS is presented. A 25 GHz single-oscillator system and a 220 GHz double-oscillator system are described. The 25 GHz system was constructed and tested in the laboratory and test results are presented. As developed, the system employs a sideband spacing of 160 MHz. Based on an estimated electromagnetic wave velocity in the plasma, a round-trip phase shift measurement accuracy of +/- 7.6 degrees was required for the desired +/- 1/2 cm distance measurement accuracy. The interaction of parallel ground and reflecting planes produces interference that prevents the basic DSBSC system from meeting the accuracy goal so a frequency modulation was added to the system to allow averaging of the measured phase deviation. With an FM deviation of +/- 1 GHz, laboratory measurements were made for distances from 5 to 61 cm tip free space. Accounting for the plasma velocity factor, 82 percent of the data were equal to or better than the desired accuracy. Based on this measured result a sideband spacing to 250 MHz could be expected to yield data approximately 96 percent within the accuracy goal.
Neece, Robert T.↗