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Phase Synchronization in Directive Antenna Arrays with Particular Application to the Radio Range Beacon

02 Oct 2018-

AbstractWith the development of the TL antenna system for use with the radio range beacon a new problem was encountered. It became necessary to provide a positive means of stabilizing the space pattern. Slight detuning of the antennas would alter the course indications. The extent to which detuning affects the pattern is demonstrated in detail and the limits to which the tuning must be maintained are shown to be very rigid. To overcome this difficulty two types of excitation systems have been developed in which the stability of the space pattern is independent of the antenna tuning to a marked degree. Either a parallel connected pair of lines 90° in electrical length or a series connection of lines 180° in length is shown to possess this characteristic. Experimental data on several types of lines show the system to be practical for use along the airways, and no sacrifice of the desirable features of the TL antenna is required. Tests of the system on actual airway range beacons show it to be satisfactory. CONTENTS Page

Topics: Omnidirectional antenna (60%), Antenna (radio) (60%), Radiation pattern (60%), Antenna measurement (58%), Dipole antenna (58%) more

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Journal ArticleDOI
01 Jan 1936
Abstract: During the past several years, the trend in broadcast transmitting antennas has been towards the vertical radiator. The performance of these newer antennas has been subject to considerable theoretical discussion. This paper, however, emphasizes the actual field results obtained with tower radiators, and presents data on efficiency, base voltage, base loss, practical design considerations, and cost. It is concluded that the conventional broadcast antenna supported by two towers, as used in the past, is definitely outmoded by the single vertical radiator, or, in special cases, by a combination of vertical radiators in a directional array. Antennas used in the broadcast band only, 550 to 1500 kilocycles, are considered.

11 citations

Journal ArticleDOI
Abstract: Radiation resistance, although ordinarily neglected, is actually of dominant importance in determining the selectivity factor Q and the input impedance Z s for both parallel-wire and concentric lines at high radio frequencies, and therefore materially changes the optimum design of the line, whether used as a low-loss inductive or capacitive reactance or to give high selectivity or high impedance as a resonant line Accurate design equations for maximum selectivity and for maximum impedance are developed in this paper for both parallel-wire and concentric lines, and curves are included showing radiation resistance, selectivity, input impedance, optimum values of spacing, conductor radius, etc It is shown that for maximum Q the optimum ratio of spacing to wire radius for parallel-wire lines is D/r = 6186, and the ratio of outer conductor radius to inner conductor radius for concentric lines is b/a = 422, as compared with values of about 36 for both ratios when radiation resistance is neglected For maximum impedance corresponding values are D/r = 2096 and b/a = 143, as compared with values of 8 and 92, respectively, predicted neglecting radiation resistance Moreover, Q and Z s are not proportional to D and b, as indicated in previous analyses; instead definite values of D and b give maximum Q and slightly larger values give maximum Z s , and even a small departure from the best value produces a large decrease in Q or in Z s

4 citations

Journal ArticleDOI
C. C. Taylor1
Abstract: IN TRANSMITTING speech over radiotelephone circuits there are a number of conventional methods of increasing the signal with respect to the noise. Examples of such methods are the use of higher power, directive antennas, diversity reception, and filters to narrow the received frequency band. In addition, there are other methods of a special character which reduce the effect of the noise interference with the speech transmission. One example of such a device limits the noise interference by eliminating the high peaks of noise of very short duration and depending upon the persistence of sensation of speech in the ear to bridge the gaps. Another method diminishes the noise in intervals of no speech. This is the method which will be discussed here.

4 citations

Journal ArticleDOI
Abstract: This paper describes a novel method of feeding the spaced-aerial system of a radio beacon transmitter, which has arisen from the consideration of the possibilities of the application of the Adcock-aerial principle to such a beacon. A brief discussion is given of the limitations of the ordinary rotating-coil goniometer arrangement for such a beacon when the transmitted power is high. The alternative method described utilizes two power amplifiers to feed the two pairs of spaced aerials. These two amplifiers are supplied with radio-frequency voltages by means of a mechanical controller which automatically provides the required time/voltage variations. A description is given of this controller, together with its application to the problem of exciting the two amplifiers. It is shown that such a controller can fulfil the requirements of the excitation apparatus, and it is concluded that the system described would be suitable for incorporation in a full-size rotating radio beacon for marine navigational purposes.

1 citations