Showing papers on "Feed line published in 1978"
Patent•
23 Jan 1978TL;DR: In this paper, a corner fed electric microstrip dipole antenna consisting of a thin eleccally conducting, rectangular shaped radiating element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface.
Abstract: A corner fed electric microstrip dipole antenna consisting of a thin eleccally conducting, rectangular shaped radiating element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The feed point is located at one corner of the antenna element and the input impedance is matched with a matching microstrip transmission feed line connected to the corner of the antenna. The length of the radiating element is greater than the width and determines the resonant frequency along the Y axis (i.e., length dimension) and the width determines the resonant frequency along the Z axis (i.e., width dimension). This antenna is capable of generating linear polarized radiation along the length thereof with minimal cross-polarization when the radiating element width dimension approaches one-quarter waveguide wavelength and less using a single corner fed element and single feed point. Elliptical polarization is also available with the rectangular radiating element.
42 citations
TL;DR: In this paper, the propagation constants of the low-frequency transmission line modes are obtained through the solution of a cubic equation, which is well justified for frequencies as high as 100 MHz for typical tunnel geometries.
Abstract: Radio frequency transmission in a semicircular tunnel containing a braided coaxial cable is considered. The general formulation accounts for both the ohmic losses in the tunnel wall and a thin lossy film layer on the outer surface of the dielectric jacket of the cable. Using a quasi-static approximation, it is found that the propagation constants of the low-frequency transmission line modes are obtained through the solution of a cubic equation. However, for the special case when the conductivity thickness product of the Iossy film layer vanishes, this cubic equation reduces to a quadratic. The spatially dispersive form of the braid transfer impedance is also accounted for. It is shown that the quasistatic theory is well justified for frequencies as high as 100 MHz for typical tunnel geometries. Finally, special characteristic impedances are derived for the various modes of the equivalent multiconductor transmission line.
19 citations
Patent•
15 Dec 1978
TL;DR: In this paper, an electric unit is used for supplying or feeding at least two service lines and for carrying out the three functions "main disconnection", "contact voltage(s) protection" and "excess current protection".
Abstract: An electric unit is used for supplying or feeding at least two service lines and for carrying out the three functions 'main disconnection', 'contact voltage(s) protection' and 'excess current(s) protection'. It is suitable for use with domestic equipment such as water heaters, washing machines and dish washers. To overcome the disadvantages of earlier types of unit wherein several lines to one consumer or load needed a separate unit in each line and a common distributor to provide protection, thus resulting in increased costs and large overloads, a main disconnector is provided in the feed line, and a fault-current member, and two or more line protection switches with thermal and magnetic tripping are provided for a line. The fault-current member excites a release or trip unit in the event of a faul-current, and the trip unit simultaneously switches all the line protection switches out of circuit.
16 citations
Patent•
15 Feb 1978TL;DR: In this article, an isolation device coupled between an antenna network and a fixed tuned VHF/UHF signal splitter includes a first bifilar transmission line wound with multiple turns about separate toroidal portions of a magnetic core.
Abstract: An isolation device coupled between an antenna network and a fixed tuned VHF/UHF signal splitter includes a first bifilar transmission line and a second bifilar transmission line wound with multiple turns about separate toroidal portions of a magnetic core. Each of the bifilar transmission lines has first and second conductors. At an input port of the device, the first conductor of the first transmission line and the second conductor of the second transmission line are coupled to respective antenna terminals of the antenna network and the second conductor of the first transmission line and the first conductor of the second transmission line are coupled together. At an output port of the device, the second conductor of the first transmission line and the first conductor of the second transmission line are coupled to respective input terminals of the signal splitter and the first conductor of the first transmission line and the second conductor of the second transmission line are coupled together. The number of turns of each of the transmission lines about its respective toroidal portion is selected to provide sufficient amplitude response in the UHF range. The permeability of the core is selected to provide sufficient amplitude response in the VHF range.
15 citations
Patent•
24 Jul 1978
TL;DR: In this paper, an adjustable attenuator, located between the transmission line and the bandpass input filter of the receiver, is used as a signal equalizer, presenting a greater impedance to signals supplied to the input filter when the local transmitter is operating, than when it is not.
Abstract: Power line carrier apparatus of the on-off type, including a local transmitter and receiver coupled to a transmission line for communication with a remote station. An adjustable attenuator, located between the transmission line and the bandpass input filter of the receiver, is responsive to the condition of the local transmitter. The attentuator functions as a signal equalizer, presenting a greater impedance to signals supplied to the input filter when the local transmitter is operating, than when it is not.
15 citations
27 Jun 1978
TL;DR: In this paper, a broadband transition between coaxial and radial transmission lines was designed by means of an equivalent circuit developed for the junction, and the design accuracy was substantiated by excellent correlation between measured and theoretical performance.
Abstract: A broadband transition between coaxial and radial transmission lines was designed by means of an equivalent circuit developed for the junction. The design accuracy was substantiated by excellent correlation between measured and theoretical performance.
12 citations
Patent•
03 Jul 1978TL;DR: In this article, a corner fed electric microstrip dipole antenna consisting of a thin eleccally conducting, square shaped radiating element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface.
Abstract: A corner fed electric microstrip dipole antenna consisting of a thin eleccally conducting, square shaped radiating element formed on one surface of a dielectric substrate, the ground plane being on the opposite surface. The feed point is located at one corner of the antenna element and the input impedance is matched with a matching microstrip transmission feed line connected to the corner of the antenna. The sides of the radiating element are all equal. The length of the element determines the resonant frequency along the Y axis and the width determines the resonant frequency along the Z axis. This antenna is capable of generating elliptical and circular polarized radiation when reactively loaded using a single element and single feed point.
12 citations
Patent•
14 Dec 1978
TL;DR: In this article, a feed line has a number of feed delivery openings and contains a fodder pump behind which is a flow meter, coupled with a pulse generator with continuously delivering control pulses proportional to the measured flow volume.
Abstract: The animal feed device is especially for pigs and uses liquid feed. It consists of a feed line which emerges from a liquid feed container and passes to stall boxes or feed points. The feed line has a number of feed delivery openings and contains a fodder pump behind which is a flow meter. A drive cut-off valve is fitted to each delivery orifice and has a switching instrument to control the valves and achieve given metering. The flow metering instrument is coupled with a pulse generator with continuously delivers control pulses proportional to the measured flow volume. The switching instrument comprises a pulse totalizer which is acted up by the control pulses and can be programmed separately for each cut off valve.
7 citations
Patent•
19 Jun 1978
TL;DR: In this article, a radio frequency (RF) antenna that includes a hollow enclosure made of a conductive material is considered, where a first portion of the hollow enclosure has a bow tie-shaped slot and a conductor is spaced apart from the slot, and is electrically isolated from the hollow enclosures; a first port that is coupled to the conductor, and a dielectric element that is made of dielectrics that at least partially fills the cavity and the bow tie shaped slot.
Abstract: A radio frequency (RF) antenna that may include a hollow enclosure made of a conductive material; wherein a first portion of the hollow enclosure has a bow tie shaped slot;; a conductor that is spaced apart from the slot, is positioned within a cavity defined by the hollow enclosure, and is electrically isolated from the hollow enclosure; a first port that is coupled to the conductor; and a dielectric element that is made of dielectric material that at least partially fills the cavity and the bow tie shaped slot; wherein the conductor is configured to perform at least one operation out of: (a) receive, via the cavity, received RF radiation and send a received RF signal to the first port; (b) receive, from the first port, a transmitted RF signal and radiating transmitted RF radiation via the cavity.
4 citations
Patent•
10 Oct 1978
TL;DR: In this article, a system particularly useful for feeding antennas employing one electrical wavelength closed loop driven elements is described. But the system is not suitable for broadcasting. And it cannot be used for broadcasting in the presence of a single antenna.
Abstract: A system particularly useful for feeding antennas employing one electrical wavelength closed loop driven elements. Single or dual wire transmission line sections provide impedance match between the high voltage, high impedance feed point on the loop and a low impedance antenna feed line. Selectable polarization with high isolation between feed lines is provided by the connection of a second transmission line section to a point located 90 electrical degrees away on the loop, at the current maximum when the other feed point is excited.
4 citations
Patent•
16 Jun 1978TL;DR: In this article, a current branching circuit for an amplifier for first and second input terminals and a current supply feed terminal comprising a pair of magnetically coupled windings with one of the windings connected between the center conductor of a coaxial feed line and one of each of the input terminals, and the other windings connecting between the other input terminals to a capacitor which has its other side connected to the outer conductor of the coaxial line, is described.
Abstract: A current branching circuit for an amplifier for first and second input terminals and a current supply feed terminal comprising a pair of magnetically coupled windings with one of the windings connected between the center conductor of a coaxial feed line and one of the input terminals and the other windings connected between the other input terminals to a capacitor which has its other side connected to the outer conductor of the coaxial line and wherein the pair of leads connecting the pair of windings to the pair of input terminals cross one another. The outer conductor of the coaxial line is connected to the current supply feed terminal through a second capacitor.
TL;DR: This model gives an insight into the strip-slot-cavity coupling and hence the working of the structure and is useful for predicting the performance of such practical antennas.
Abstract: An equivalent network for the strip-fed cavity-backed slot antenna is derived. The model is based on some physical insight into the problem. The various parameters of the network are derived from the experimental data on the input reflection parameter of the antenna. This model gives an insight into the strip-slot-cavity coupling and hence the working of the structure. It is also useful for predicting the performance of such practical antennas.
Patent•
05 Jan 1978TL;DR: The omnidirectional antenna consists of two sections along a common axis, and operates with two different frequencies and polarities as discussed by the authors, and is fed by double coaxial feed line from one side only.
Abstract: The omnidirectional antenna consists of two sections along a common axis, and operates with two different frequencies and polarities. It is fed by double coaxial feed line from one side only. The omnidirectional radiator, facing the feed side, is in the form of a known unipole, radiating vertical, linearly polarised electromagnetic waves. The outer conductor (2) of the external coaxial feed line is angled towards a base plate (5). A region of the associated inner conductor (3) is in the form of a quarter wavelength rod radiator (1). The omnidirectional radiator, away from the feed side, is in the form of spiral antenna element (7) for radiation of a circularly polarised electromagnetic waves.
Patent•
06 Apr 1978
TL;DR: In this paper, the decoupling resistance of the choke is selected as high as possible, in order to form a current node, which is formed by a line transformer whose wave resistance is the same as that of the supply cable.
Abstract: The directional antenna, particularly a U-shaped adcock, has each individual antenna with a diametral earthing line (5) relative to the antenna supply cable (3). The latter contains a choke (6) at a given distance from the individual antenna. Pref. the lengths of the earthing line and the supply cable are identical between the choke and the individual antenna. Alternative the earthing line length is somewhat smaller. The effective dia. of the earthing line and of the supply cable may be also identical. The decoupling resistance of the choke is selected as high as possible, in order to form a current node. The choke may be formed by a line transformer whose wave resistance is the same as that of the supply cable.
Patent•
21 Dec 1978