The Determination of the Direction of Arrival of Short Radio Waves

Friis, H.T.; Feldman, C.B.; Sharpless, W.M.

doi:10.1109/jrproc.1934.226347

Cited by 30 publications

(12 citation statements)

References 11 publications

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“…Reconfigurability is the capacity to change a radiator's operating characteristics, such as frequency of operation, impedance bandwidth, and radiation pattern. Reconfigurable antennas have been in existence since the early 1930's, when the nulls of a two-element array were steered by a phase changer to determine the arrival direction of a signal [27]. The most common methods utilized to achieve reconfigurability have since been through the use of phase shifters, attenuators, diodes, tunable materials, active materials, microelectromechanical structures (MEMS) or mechanical methods via moving parts [28].…”

Section: Flexible ''Origami'' Reconfigurable Antennasmentioning

confidence: 99%

Additively Manufactured Nanotechnology and Origami-Enabled Flexible Microwave Electronics

et al. 2015

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| Inkjet printing on flexible paper and additive manufacturing technologies (AMT) are introduced for the sustainable ultra-low-cost fabrication of flexible radio frequency (RF)/microwave electronics and sensors. This paper covers examples of state-of-the-art integrated wireless sensor modules on paper or flexible polymers and shows numerous inkjetprinted passives, sensors, origami, and microfluidics topologies. It also demonstrates additively manufactured antennas that could potentially set the foundation for the truly convergent wireless sensor ad-hoc networks of the future with enhanced cognitive intelligence and ''zero-power'' operability through ambient energy harvesting and wireless power transfer. The paper also discusses the major challenges for the realization of inkjet-printed/3-D printed high-complexity flexible modules as well as future directions in the area of environmentally-friendly ''Green'') RF electronics and ''Smart-House'' conformal sensors.

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Section: Flexible ''Origami'' Reconfigurable Antennasmentioning

confidence: 99%

Additively Manufactured Nanotechnology and Origami-Enabled Flexible Microwave Electronics

et al. 2015

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“…In the mid‐latitude range of the communication 1, effects of the different layers separate the angle of different paths at about 10$^{\circ }$ and that of the roughness at a few degrees. This angle spread is found mainly in elevation direction, and that in horizontal direction is relatively small because the multipath signals are coincided horizontally with the arc of great circle 2, 3.…”

Section: Introductionmentioning

confidence: 95%

Studies on the coherence bandwidth of high‐frequency vehicular communication system with antenna array

Li¹,

Duan²,

Ma³

et al. 2011

Wireless Communications

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High-frequency (HF) vehicular communication system works with the frequency-selective fading channel, thereby the coherence bandwidth is limited due to the multipath time dispersive effect, which imposes the difficulty for achieving the high-data rate transmission. The present paper investigates the antenna array technique for its ability in reducing the multipath delay spread of the ionosphere channel and, thus, increasing possibly the bandwidth of the HF system. To enable fast moving speed of the vehicular receiver, we propose to use single antenna at the receiver and the adaptive array at the transmitter. The adaptive beamforming is driven based on the protocol design and reciprocity principle of channel. In order to evaluate the performance of array system, a statistical HF double-directional channel model, which includes angular information at both the transmitter and receiver, is presented. The explicit expressions are obtained for calculating the coherence bandwidth. The numerical results show the efficiency of this approach for mid-latitude mid-range channel.

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“…Friis, Feldman, and Sharpless 1934;Ross, Bramley, and Ashwell 1951;Miya 1954;Bain 1961). The present paper describes a phase comparison method and an electronically controlled phase changer.…”

Section: Introduotionmentioning

confidence: 99%

Elevation Angles of Ground Backscatter at 16 MHz and Large-Scale Ionospheric Tilts

Mir¹

1969

Aust. J. Phys.

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SummaryA technique of recording the elevation angle by a phase comparison method is described and applied to ground backscatter echoes at 16 MHz. It is shown that the results may be explained in terms of ionospheric tilts of 1 ° or 2° near sunset. INTRODUOTIONSeveral methods are at present available to measure the angle of elevation of ionospheric radio waves at receiving stations (e.g. Friis, Feldman, and Sharpless 1934;Ross, Bramley, and Ashwell 1951;Miya 1954;Bain 1961). The present paper describes a phase comparison method and an electronically controlled phase changer. The aim of this project was to measure elevation angle of ground backscatter echoes and to test the extent to which the theory of Appleton and Beynon used by Shearman (1956) and later by Steele (1965a) is valid. The pre-sunset and post-sunset results are compared with the theory and the discrepancy is explained by involving a tilted ionosphere.II. EXPERIMENTAL TEOHNIQUE AND REOORDINGThe transmission was carried out at 16 MHz by a highly directive backscatter sounder (Thomas and McNicol 1960) from Brisbane (lat. 27 ·5° S., long. 152 ·9° E.). A pulse of 800 fLsec with a repetition frequency of 8 ·33 sec-1 was transmitted using an array of four three-element Yagi antennas. The Yagi array was aimed in a fixed direction, usually to the east or to the west. The calibration of the horizontal and vertical radiation pattern of the antenna system has been treated in detail elsewhere (Steele 1965b; McInnes 1966). The same antenna system is used for transmission and reception. The Brisbane receiver is used to record a range-amplitude display of the signal on a film moving continuously past the trace on an oscilloscope screen that is displayed by brightness or black-out modulation of the time-base trace. The gain of the receiver was decreased in 12 steps of 3 dB each over a period of 1 min.Two similar Yagi antennas, located 5'\ (,\ = 18·75 m) apart along an east-west direction on the ground, were used for the measurement of the elevation angle at Amberley (lat. 27 ·7° S., long. 152.7° E.) about 20 miles from Brisbane. The output of the two antennas was received as shown in the block diagram of Figure 1. In the signal path from one antenna was inserted a continuously-scanned phase changer, which changed its phase uniformly between 0° and 360° in 30 sec. The output of the other antenna and the output of the phase changer were added, amplified, and passed through a gated amplifier that selected a narrow slice (equivalent to 10 km) of the leading edge of the ground backscatter echo. The selected portion of the echo brightened the spot of a cathode ray tube, which was then photographed on a continuously

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The Determination of the Direction of Arrival of Short Radio Waves

Cited by 30 publications

References 11 publications

Additively Manufactured Nanotechnology and Origami-Enabled Flexible Microwave Electronics

Additively Manufactured Nanotechnology and Origami-Enabled Flexible Microwave Electronics

Studies on the coherence bandwidth of high‐frequency vehicular communication system with antenna array

Elevation Angles of Ground Backscatter at 16 MHz and Large-Scale Ionospheric Tilts

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