Showing papers on "Feed line published in 1991"

A microstrip patch antenna with coplanar feed line

Abstract: An experimental investigation of a microstrip patch antenna with a coplanar feed line is presented. The coupling from the coplanar line to the patch is accomplished via a slot in the ground plane to which the coplanar line is connected either inductively or capacitively. The input return loss can easily be adjusted via the slot length. Additional frequency tuning is possible by switching between inductive and capacitive coupling. >

Antenna diversity receiving system with antenna switching during line periods and signal quality evaluation during line blanking intervals

Abstract: Antenna diversity receiving system for mobile reception of television signals having N antenna inputs, one diversity processor with as many inputs, and connected downstream in the system to a television receiver, the video signal of the television receiver and the line and picture synchronizing signals being applied to the diversity processor. The diversity processor comprises a time gate circuit which is opened by the line synchronizing pulses during the line blanking interval and switches the video signal through to the signal quality evaluation circuit. At that location an output signal having the signal quality of the video signal is produced which is applied to the control circuit. In the case of an imminent picture disturbance the control circuit produces an address signal so that very rapidly a new antenna signal or a linear combination derived from the antenna signals is applied to the television receiver by means of the antenna combiner. Particularly advantageous is the fact that during the line blanking interval the signal quality of all available HF signals is tested and the one HF signal having the best signal quality is switched through to the television receiver during the remaining time interval.

Antenna selection switch for a diversity antenna

Abstract: The invention relates to a circuitry by means of which it is possible to switch to a mobile telephone that antenna out of two or more antennae which has the best signal, without substantial alterations in the mobile telephone itself. According to the invention, the antennae (A, B), the antenna selection switch (2) and the peripheral circuits (5, 6) connected to it constitute an integrated part which is separate from the actual mobile telephone (1) but can be coupled to it by means of an antenna cable (3), and the antenna cable (3) is coupled to the radio part of the mobile telephone (1) by mediation of a signal combining circuit (4) which transfers to the antenna cable (3) the supply voltage (V) and the antenna selection switch (2) control pulse, and transfers and selects the RF signal.

The dielectric-filled parabola: a new millimeter/submillimeter wavelength receiver/transmitter front end

Abstract: A design is presented for a semi-integrated millimeter/submillimeter wavelength receiver/transmitter front end incorporating a planar antenna and a solid-state device in an efficient feed structure which can be matched directly to high f-number optical systems. The feed system combines the simplicity and robustness of a dielectric substrate lens with the high gain of a parabolic reflector in a single structure that is termed a dielectric-filled parabola. The same fundamental unit can be configured as either a heterodyne or direct detection mode receiver, a power transmitter or a frequency multiplier by changing out the solid-state device and/or the integrated antenna. The structure can also be used with a small integrated antenna array in a multibeam or imaging arrangement. Design and fabrication details for the feed system are given. These are followed by beam pattern and impedance measurements taken on a microwave model when dipole, bow-tie, log-periodic, and log-spiral antennas are used as the integrated feed elements. >

Electronic assembly for range finding using radio wave signal strength

Abstract: A radio range finding system includes a radio frequency transmitter adapted to be located adjacent an area in which distance is to be monitored, a transmitting antenna, and a receiver unit. The receiver unit has a multiplicity of radio signal receivers each having a highly directional receiving antenna with the receiving antennae of the multiplicity of receivers having their axes of maximum sensitivity oriented in different directions, and an analyzer for determining a composite of the field strengths of the radio signals received by the receiving antennae, and providing an output indicative of the composite field strength. The receiver may detect when the composite field strength at the receiving antennae fails below predetermined values, and generate a signal at that time. The vector sum of the field strengths of the radio signals are derived from the square root of the sum of the squares of the field strengths of the several signals. The field strength signals are multiplexed and converted to a DC voltage by an RMS to DC converter. The transmit antenna is a loop comprising one or more turns shielded by two partial spaced apart shields, each connected only to the shield of the antenna cable at its junction to the loop.

Power feed line switching circuit for submarine branching device and method of feeding power to submarine cable communication system

Abstract: A power feed line switching circuit for a submarine branching unit includes first, second and third electrical paths (101, 102, 103), connected e.g. in a Y-shaped connection, and first, second and third terminals (104, 105, 106) connected respectively thereto. The circuit further comprises first and second relays (107, 108) each including driving units (107L, 108L) inserted in the first and second electrical paths (101, 102) and switching units (107C, 108C) for disconnecting the corresponding terminals (105, 104) and connecting the terminals (105, 104) to the ground, respectively. A third relay (109) has a driving unit (109L) and its switching unit (109C) forms a lock-up circuit for the grounding path (110) for terminal (105). These relays (107, 108, 109) are used to control the connections between the terminals (104, 105, 106) and electrical paths (101, 102, 103), for establishing a one-end power feed line or a both-end power feed line to maintain power feed for repeaters and the submarine branching unit by the plurality of relays, even though a fault is caused in the optical marine cables for cable landing stations.

Emergency and operational low and medium frequency band radio communications system for underground mines

Abstract: A minewide low and medium-frequency radio system has been developed and installed in coal and metalliferous mines. The radio system utilizes two robust radio signal transmission modes to establish underground radio coverage areas. The seam transmission mode occurs when layers in the ground form a natural waveguide. The conductor transmission line mode waveguide occurs when electrical conductors, such as AC power distribution cables, are in place in mine passageways. The author describes the development history of MF band technology during the past five decades in South Africa, Europe, and the United States. How EM wave theory guided the design and development of the conductor transmission line repeater network and associated mobile radio equipment is discussed. The safety and cost reduction benefits of a practical radio system are also described. >

Method and apparatus for providing wireless communications between remote locations

Abstract: METHOD AND APPARATUS FOR PROVIDING WIRELESS COMMUNICATIONS BETWEEN REMOTE LOCATIONS Abstract A wireless telecommunication system includes a microwave link between a main base station (100) and a remote reception and radiation site (106) capable of communicating with a plurality of telephone subscriber stations (107,108). At the main base station (100), radio frequency signals intended for the telephone subscriber stations are modulated (204) on a microwave frequency carrier signal prior their transmission, via a microwave antenna (112), to the remote site. At the remote site (106), the frequencies of the microwave signals, received at a microwave antenna (114), are reduced prior to modulating such frequency-reduced signals on a radio frequency carrier signal (302) and radiating, via a radio frequency antenna (115), the modulated radio signals out of the site. All radio signals received at the remote site from telephone subscriber stations are modulated on a microwave carrier signal (303) prior to their transmission, via a microwave antenna (114), to the main base station (100). At the main base station (100), the frequencies of the incoming microwave signals are reduced (208) prior to modulating such frequency-reduced signals on a radio frequency carrier signal (210) and coupling the modulated radio signals to a receiver.

A fuel flow arrangement

Abstract: A fuel flow arrangement has a fuel feed line (14) for feeding fuel from a tank (10) to an engine (12) with a fuel injection pump (20) by means of a pump (18), and a fuel return line (16) for returning excess fuel from the engine to the tank. A bypass passage (21) with an orifice (22) provides a communication between the feed and return lines and a flow restriction (24) is provided in the return line. When the fuel pressure created by the pump (18) is low, at low temperatures, fuel entering the return line will be recycled through the orifice (22) to the engine to increase the temperature of the fuel feed to the engine, and at higher temperatures, the flow through the orifice (22) will be reversed.

Base station for a radio communication system

Abstract: A base station for a mobile communications system including an antenna for transmitting a radio carrier wave to a mobile communications device and receiving signals therefrom, a coaxial external conductor including a skirt in the form of a sun shade having a length equal to a quarter wavelength of the radio carrier wave, a radio section located inside the coaxial external conductor for providing radio communication with the mobile communication device via the antenna, and a connecting section connecting the radio section to a telephone line and where the antenna is configured in the form of an upper disk of a discone antenna and where the skirt is a lower conical member of the discone antenna.

Phase shifting network and antenna and method

Abstract: A method of and apparatus for transmitting or receiving circularly polarized signals is disclosed. The technique employs a phase shifting network for connection between an antenna and a radio transmitter or receiver to produce a phase shift when transmitting or eliminate a phase shift when receiving. In one preferred embodiment, a dielectric substrate has a phase shifting network or printed circuit lines defining a signal transmission paths between a radio connection terminal and a plurality of antenna element connection terminals for coupling a multi-element antenna and a radio. Each transmission path is phase shifted relative to an adjacent path by a predetermined amount by each path having progressively equally different electrical length to provide equal phase shift of a radio frequency signal progressively through the transmission paths. Adjacent path pairs are progressively joined at combiner nodes of equal power division by shunt connection line segments to that the power at each antenna connection terminal is equal to the power at the radio connection terminal divided by the number (typically four) of antenna terminals.

A measure of coupling efficiency for antenna penetrations

Abstract: The electromagnetic penetration into a shielded enclosure through an antenna connected to a receiver inside the shield is discussed. Reciprocity is used to relate the far-zone fields to the short circuit current in the transmission line. Using a Norton equivalent circuit, a measure of coupling efficiency is derived, relating the electric field incident on the antenna to the current incident on the receiver. It is shown that the coupling efficiency can be determined from standard electromagnetic measurements. As a first example, an open-ended coaxial waveguide is considered. As a second example, a transmission line connected to a receiver inside the shield and to a center-fed dipole antenna outside the shield is discussed. Numerical results are presented for the dipole for various receiver bandwidths and transmission line characteristics. The results are given both in the frequency domain and in the time domain for a pulse incident field. >

Information transmission system of the state of loads connected to an electric line

Abstract: The purpose is to supervise and demonstrate the state of a plurality of loads (4) connected to an electric line such as for example the lamps of the public lighting lines, machines, etc. It has a central control unit (1) that is connected to a plurality of sector control units (2), which in turn, each one of them is connected by an electric feed line (9) to a plurality of load control units (2) through which the load (4) is connected, detecting and storing the possible failures. The information transmission is carried out when there is no feed in the lighting network. The connection between the load control units (3) and the sector control units (2) can be done through the control line (22), avoiding additional wiring.

Broadband, inductively coupled, duplex, rf transmission system

Abstract: A broadband, inductively coupled, duplex, radio frequency (RF) transmission system for communcating between a central unit (10) and a plurality of remote units (31) is disclosed. The central unit (10) includes an RF signal source (11) and an RF receiver (21) connected to one end of a balanced transmission line (25) via a signal splitter (15) and a transmission line impedance matching network (27). Each remote unit (31) includes a receiving section (33) and a transmitting section (35) separate from one another. Each receiving section (33) and each transmitting section (35) includes U-shaped couplers (37,43) positioned so as to overlie the balanced transmission line (25). The U-shaped couplers (37,43) are oriented such that the cross-members of the U-shaped couplers (37,43) lie orthogonal to the balanced transmission line (25) and the legs of the U-shaped couplers (37,43) lie parallel to the balanced transmission line (25). The legs of the U-shaped couplers (37,43) are connected to electronic transmit and receive system RF receivers and Rf signal sources (41,47), via impedance matching networks (39,45).

Electrical transmission cable termination device having short and open-circuit cable test capabilities

Abstract: A electrical transmission line termination device capable of performing various termination requirements including matching the line impedance of wires in a transmission line with load impedances, electrically connecting conductors in a transmission line for maintaining electrical continuity, detecting improper wiring of the various wires in a transmission line, and connecting a cable shielding conductor to a ground wire.

A matching device for a microstrip antenna

Abstract: A matching device for an antenna in which is interposed between an antenna of narrow frequency band and a feeding line so as to match the antenna and the feeding line over a wide band, includes a high impedance line of a first predetermined length provided at the antenna side and a low impedance line of a second predetermined length provided at the feeding line side that are connected in series, whereby the matching device can be made small in size and simple in construction.

Device for feeding an antenna element radiating two orthogonal polarisations

Abstract: The present invention relates to a feed device for a radiating element operating with dual polarisation, comprising a first feed line (11) penetrating into a first cavity (13) situated beneath the said radiating element (10), and a second feed line (12) arranged according to a geometry orthogonal to the first line (11) and penetrating into a second cavity (14) situated in the continuation of the first, a conductive part (16) forming a coupling slot (19) between these two cavities (13, 14). Application in particular to the field of space transmissions.

Microwave integrated circuit device having impedance matching

Abstract: A microwave integrated circuit includes a matching circuits. The microwave integrated circuit includes a main transmission line having a strip line and a shorted stub or an open stub, all of which are arranged on a semiconductor substrate. A phase control circuit connected in parallel with the main transmission line controls the passing phase of the main transmission line. Therefore, the electrical length of the main line can be changed and the passing phase through the main line can be controlled for adjusting impedance matching in accordance with changes in the impedance of the element to be matched, resulting in precise impedance matching at a desired frequency.

Microwave plate antenna printed on a substrate

Abstract: The present invention relates to a micro-wave plate antenna, especially for Doppler radar for example, of the type with a Janus configuration, made up of a plurality of linear sub-networks parallel among themselves, or of a single linear sub-network, each sub-network being made up of a plurality of radiating elements placed on each side of a sub-network feed line, the sub-networks being fed in phase, the length of the sub-network feed line is, between two neighboring elements, a whole multiple of the length of the wave guided over the substratum of the printed circuit on which are printed the radiating elements, and that corresponds to the operational frequency of the antenna. It is such that between two neighboring radiating elements of a same sub-network, the sub-network feed line has at least one bend so that the distance projected on the axis parallel to the transverse direction of the sub-network between two consecutive radiating elements of a same sub-network is inferior to the dimension of these elements in that direction.

Radiating antenna cable apparatus

Abstract: A distributed antenna system for wireless communication inside enclosed areas such as buildings, tunnels, etc., includes an antenna cable and a termination circuit which provides a plurality of termination impedances for the cable, varying as a function of time. The termination circuit may include a diode coupled to the cable at a remote end of the cable and a bias voltage generator coupled to a local end of the cable. Changes in bias voltage alternately forward biases and reverse biases the diode, effectively changing the termination impedance of the antenna cable. As the impedance changes, nodes and regions of high multipath distortion move, so the probability is greatly increased that personnel with remote communication equipment will be able to send and receive good quality signals over the antenna cable at any given location.

Production of uniform droplet group

Abstract: PURPOSE: To efficiently produce uniform droplet groups by filtering a raw material liquid through a filter installed just before many nozzle holes in dropping the raw material liquid in the perpendicular direction under vibrating conditions in the vertical direction and forming the droplets CONSTITUTION: A suspensionlike or an emulsionlike raw material liquid containing a solid, a gel or a liquid is dropped from many nozzle holes in the perpendicular direction while forming droplets under vibrating conditions in the vertical direction In the process, the raw material liquid is filtered through a filter having an opening of ≤1/3, preferably ≤1/5 the diameter of the nozzle holes installed just before the nozzle holes to prevent the nozzle holes from being clogged with foreign materials The rectified raw material liquid is then passed through the nozzle holes to efficiently produce droplet groups having a uniform particle diameter For example, an apparatus equipped with a nozzle 2 fixed to a nozzle holder 3 and the filter 14 installed just before the nozzle 2 is used to feed the raw material liquid from a liquid feed line 13 thereinto and the droplet groups are dropped while vibrating the whole nozzle holder in the vertical direction COPYRIGHT: (C)1993,JPO&Japio

Aerial radiator with base element as ground surface - has elliptical conductive patch element at selected spacing from base element for resistance matching

Abstract: The aerial radiator has a base element (1) serving as a ground surface arranged at a distance (H) from a patch element (5), forming a conductive surface. Between the base and patch element a low-loss dielectric is fitted. The radiator has a coaxial feed line (2), whose outer conductor (3) is coupled to the base element, while the inner conductor (4) is linked to the patch element. The latter is in the form of an ellipse, and the spacing between the two elements is so selected that a resistance matching takes place between the two elements and the feed line. Pref. air is used as the dielectric. The patch element may be hexagonal of two mirror-identical trapezoidal surfaces. USE/ADVANTAGE - For aerial radiators of patch type, with great band width and identical radiation widths in the E and H plane.

Microwave plasma treating device

Abstract: PURPOSE: To produce high-density plasma and to increase the plasma treating rate by providing a slow-wave circuit in the propagation region of the microwave. CONSTITUTION: A vacuum treating chamber 10 is evacuated, and a gaseous etchant is introduced into a slow-wave circuit 19 and the chamber 10 through a gas feed line 23 to adjust the pressure to a specified value. A solenoid coil 18 is excited, and a magnetic field leading to a sample holder 12 is generated. A microwave is oscillated from a magnetron 17, propagated in a waveguide 16, transmitted through a quartz window 20 and injected into the chamber 10. The phase velocity of the microwave is reduced by the slow-wave circuit 19, and the processing gas in the space in the circuit 19 is excited by the interaction between the electric field of the microwave and the magnetic field of the solenoid coil 18 and converted to plasma. Consequently, the microwave energy is efficiently transmitted to the processing gas, and the processing gas is efficiently converted to plasma. COPYRIGHT: (C)1992,JPO&Japio

Electronic hardware package

Abstract: A connector for RF packages which provides both RF and DC signals to the package. The connector comprises a silicone block with an embedded RF jumper which connects an RF conductor on the package to an RF feed line. The block also has numerous conductive strips passing through it. These conductive strips connect DC feed lines to DC input pads on the package. The connector is compressed by means of a cover, deforming the elastomer block. The block serves to envornmentally seal the RF and DC inputs from the environmental effects.

Radio transmitter apparatus

Abstract: A radio transmitter apparatus arranged such that transmission efficiency is improved by switching a load impedance of a final stage in response to a power source voltage or a transmission output.

Measurement of the microwave properties of micron-sized coplanar transmission lines

Abstract: A method of measuring the properties of micron-sized slow-wave coplanar transmission lines is presented. The transmission line's propagation constant γ and characteristic impedance Zo are determined directly from the measured S-parameters of a section of transmission line. Measurements are made with microwave "on-wafer" probes. Test data from 0.5 to 40 GHz is presented on a relatively low-loss slow-wave coplanar transmission line fabricated on silicon. The measured quality factor of the transmission line is seen to approach 10 at 11 GHz with a wavelength-compression factor of approximately 5.6.

Frequency-scanned antenna arrays

Abstract: A means for scanning a beam over a two-dimensional sector in space comprising a two-dimensional array (8) of radiating elements excited by a signal of variable frequency via a single travelling wave feed line (7). The lengths of the lines from each element to its junction with the feedline are made equal and the lengths of feed line between each of the junctions are equal. Alternatively, fig. 5 phase shifting sections (10a, 10b, 10c, 11a, 11b) positioned between adjacent radiating elements are set so that the array can be scanned in raster fashion.

Microwave circuit with integrated antenna

Abstract: PURPOSE: To arrange the antenna and the microwave circuit on one dielectric substrate by forming the microwave circuit on the other plane of the dielectric substrate forming the radial conductor of the antenna. CONSTITUTION: For the microwave circuit with integrated antenna, a mixer circuit is constituted by providing a radial conductor 3 of the microstrip antenna and a branch filter 10 of a microstrip line coupled to the conductor on one plane of the dielectric substrate and providing a coplanar circuit equipped with a coplanar line on the other plane, and the antenna and the mixer are integrated. When an integer is defined as (n) and one wavelength on the coplanar line constituting the mixer circuit is defined as λ, the line length of the said line is (λ/4)+(nλ/2), the above-mentioned coplanar line is used as a feeder line, and power is supplied from the coplanar line through a conductor, which is passed through the front and rear sides of the dielectric substrate, to the radial conductor. COPYRIGHT: (C)1992,JPO&Japio

Device for connecting an antenna to radio transceivers

Abstract: The coupling device is intended for connecting an antenna (3) to a first radio communication unit (1) operating at a first frequency, or a second radio communication unit (2) operating at a second frequency which is essentially twice the first frequency, and comprises a first spur (4) having a first transmission line segment (6) of length equal to a quarter of the wavelength of transmission of the second frequency, and a second, branch-mounted transmission line segment (7) having a length equal to half the wavelength of transmission of the second frequency, and a second spur (5) mounted in parallel with the first spur and comprising a third transmission line segment (10) having a length equal to a quarter of the wavelength of transmission of the first frequency, and a fourth, branch-mounted transmission line segment (11) having a length equal to a quarter of the wavelength of transmission of the first frequency.

A general method for treating infinite arrays of antennas printed on protruding dielectric substrates

Abstract: A full-wave approach has been developed to analyze a wide variety of radiating elements (including the dipole element with feed lines) printed on one side of a protruding substrate in an infinite array environment. The method is outlined, and examples of results are presented for the dipole element fed by a coplanar strip transmission line. >