Showing papers on "Feed line published in 1995"

Microstrip flexible printed wiring board interconnect line

Abstract: An RF flexible printed wiring board transmission line for connecting strip transmission line microwave assemblies without the use of coaxial connectors and coaxial cables. The flexible transmission line includes a thin flexible dielectric ribbon, having on one side a ground plane layer and on the other side a microstrip conductor strip. Plated through holes at the ends of the flexible line provide access to both the ground plane and conductor strip on the same side of the flexible line, to facilitate interconnection of the microwave assemblies to the flexible line. The flexible line operates at microwave frequencies with little or no radiation leakage.

Direct connect radio and antenna assembly.

Abstract: A direct connect antenna includes a passive patch-type antenna 12 mounted to a radio 14, wherein the need for and use of a coaxial cable extension arrangement is eliminated. Thus, the characteristic impedances of the load and source can be better matched, resulting in lower reflection and distributed losses. The antenna 12 is formed with guide slots 40 and 42 for alignment and simple snap-on connection of the antenna 12 to the radio 14 to prevent coaxial connector mismatch and damage. The radio 14 may be directly affixed and electrically coupled to a PCMCIA compliant interface card 16 which is insertable into a host computer. Accordingly, radio signals received by the direct connect antenna and radio arrangement are processed through the PC card 16 and the computer.

Power line communications system and coupling circuit for power line communications system

Abstract: A coupling circuit for a power line communications system for coupling information signals from a transmitter unit to a power line and for coupling information signals from the power line to a receiver unit. The coupling circuit includes: (a) a ferrite core coupler for isolating the transmitter unit or the receiver unit from a power line and for coupling information signals from the transmitter unit to the power line and from the power line to the receiver unit, (b) a bandpass filter for selectively passing information signals from the transmitter unit to thew power line and from the power line to the receiver unit, and (c) an impedance matching pad for matching the impedance of the transmitter unit to the impedance at an outlet connected to the power line and to which the transmitter unit is connected and the receiver unit to the impedance at an outlet connected to the power line and to which the receiver unit is connected.

Bidirectional printed antenna

Abstract: A bidirectional printed antenna includes a dielectric substrate (33) having first and second surfaces which are substantially in parallel, at least one pair of radiation element conductors (31, 32) having the same shape and the same size, each pair of which is arranged on the first and second surfaces at positions opposing with each other, respectively, a feeding circuit (34, 35, 36, 37) coupled to at least one edge of each of the radiation element conductors, and a ground conductor (37) arranged on the second surface The ground conductor (37) covers at least an area outside of the edge of the radiation element conductor, which edge is coupled to the feeding circuit, and an area outside of the opposite edge with respect to the radiation element conductor by leaving a gap of a predetermined width between the radiation element conductor and this ground conductor The antenna further includes a first strip conductor (34, 35) arranged on the first surface and connected to the radiation element conductor (31) on the first surface; and a second strip conductor (36) arranged on the second surface, for connecting the radiation element conductor (32) on the second surface with the ground conductor The above-mentioned feeding circuit includes an unbalanced feed line which consists of the ground conductor (37) and the first strip conductor (35), and a balanced feed line which consists of the first and second strip conductors (34, 36)

Radio base station, radio local area network and optical fiber feeder

Abstract: PROBLEM TO BE SOLVED: To supply a radio signal to an antenna dead zone by providing an optical transmission line ease of connection with low noise at a low cost with respect to an antenna feeder in a radio communication system. SOLUTION: A radio signal 100 from a mobile terminal equipment 3 is received by an antenna 71a and converted into an optical signal 202a by an optical transmission section 11a. The optical signal 202a is sent to a radio base station 5 by a multi-mode optical fiber transmission line 2a and converted into a radio signal 106a by an optical receiver 13a. The radio signal 106a uses an optical branching device 30 to add radio signals from antennas 71b, 72 and the sum is given to a MODEM 40. Furthermore, the radio base station 5 branches an output radio signal 109 from the MODEM 40 by the branching device 30 and part of signal is converted into an optical signal 201a by an optical transmitter 10a. The optical signal 201a is sent through a multi-mode optical fiber transmission line 1a and converted into a radio signal 103a by the optical receiver 12a and emitted from an antenna 71a and received by a mobile terminal equipment 3.

A radio transmission system and a radio apparatus for use in such a system

Abstract: Known are radio transmission systems (1) with phased-array radio apparatuses (2) operating in a multipath transmission environment. The known radio apparatuses try to optimise a reception direction. In strongly varying environments such as in cellular radio systems or cordless telephony systems, the known systems (1) do not operate satisfactorily, because absorbing or reflecting objects and strong interference sources are not taken into account sufficiently. Improved reception is proposed, and in bi-directional systems, also improved transmission. This is achieved by using at least two reception beams, one fixed reception beam, and one scanning reception beam, and by continuously evaluating the quality of these beams as to their signal-to-noise-and-interference ratios or bit-error-rates (BERs). The best beam is dynamically chosen to be the fixed beam. Alternatively, the fixed beam is updated with the best beam acquired by the scanning beam as compared to the current fixed beam. In a bi-directional system (1), the receiving radio apparatus (2) applies the direction of the best reception beam for transmission to the opposite radio apparatus (5).

Optical transmission/reception antenna system

Abstract: PROBLEM TO BE SOLVED: To avoid the occurrence of a fault owing to lightning and to execute long distance transmission without the need of power for a transmission/reception antenna and without causing the transmission fault by applying the light propagation and photoelectric conversion of an optical system and providing light transmission parts for a transmission antenna system device and a reception antenna system device. SOLUTION: The transmission antenna system device is constituted by a light source 6 emitting an electric signal as signal emitting light, an optical fiber for propagation 18, a photoelectric converter 8 converting transmission signal emitting light into the electric signal and a transmission antenna 2. The reception antenna system device is constituted by the light source 6 emitting light, an optical fiber for incidence/ propagation 19, an reception antenna 3, a transmission type optical modulator 9 modulating the intensity of the propagated/emitted light in accordance with the voltage of the input electric signal and emitting it as modulated incident light, an optical fiber 20 for propagating emission, an optical fiber for emission/transmission and a photodetector 7 detecting propagated/modulated incident light. A line between the signal light source 5 and the transmission antenna 2 and that between the reception antenna 3 and the photodetector 7 are optical cable transmission lines. COPYRIGHT: (C)1997,JPO

Coaxial-to-coplanar-waveguide transmission line connector using integrated slabline transition

Abstract: A coaxial-to-coplanar-waveguide connector that incorporates a slabline section within the coaxial connector interface between a circular-coaxial-transmission-line-to-coplanar-waveguide transmission line. As RF energy enters a circular coaxial input, the slabline section shapes the electromagnetic field distribution to more closely resemble that of coplanar waveguide at the output. The slabline section provides better field matching from the circular coaxial transmission line to the coplanar waveguide transmission line. Angular bends and lateral offsets can readily be incorporated in the connector.

Wireless digital communication system, a radio apparatus, a digital speaker, and a digital speaker controlling apparatus

Abstract: Wireless digital communication systems apply an antenna diversity scheme to combat fading in a received signal as received by a receiver in the system. A radio apparatus having a single receiver front-end comprises a simple and robust antenna diversity scheme. In the system, digital radio signals are transmitted to the radio apparatus, wherein the transmitted radio signals comprise redundant information for allowing error correction at reception side. The error correction capability at reception side is applied for antenna diversity switching. Within the error correction capability of an error correction decoder comprised in the radio apparatus, the radio apparatus searches for a better antenna or antenna combination. When a better antenna or antenna combination is found, the receiver front-end is coupled to the better antenna or antenna combination.

Dual function antenna structure and a portable radio having same

Abstract: A dual function antenna structure transceives in first and second modes. A first feed (120) feeds a primary antenna element (110) for operation in the first mode. A second feed (240) connects to the first feed (120). An upper choke (150) and a metal layer (160) are tuned to a wavelength of the radio frequency energy to be transceived in the second mode. The primary antenna element (110) and the metal layer (160) thus realize a secondary antenna element for operation in the second mode. In a portable radio, dual function operation is thus possible by a compact structure by the first and second feeds (120, 140).

Radio with antenna connector having high and low impedance points

Abstract: A radio transceiver of the present invention includes a transmission line within a housing. The transmission line is comprised of a hollow center conductor and an outer conductor, both connected to a transceiver circuit. The transmission line is also connected to a low impedance connector which is coupled to the housing. A retractable 1/2 wave antenna having an integral matching section will be matched to a transceiver circuit when extended. When the antenna is retracted, the antenna is retracted within the center conductor and acts as a 1/4 wave antenna and will still be matched to the transceiver circuit.

Method and device for contact-free measurement of the mass flow rate in a two-phase pneumatic transport using microwaves

Abstract: The mass flowrate measuring system uses the detected microwave propagation time and/or the microwave attenuation for different dielectric characteristics of the flow phases. Part of the feed line for the dual phase flow is provided as a hollow waveguide measuring path supplied with the microwave pulses with a base frequency selected in dependence on the dia. and mean dielectric constant of the measuring path. The microwaves are supplied with different azimuthal orientations for obtaining circularly or elliptically polarised microwaves within the measuring path, the measurement effected using several different frequencies and a number of separate transmission and reception devices.

Radio receiver for use in a radio tracking system

Abstract: A radio receiver unit for directionally tracking at least one radio transmitter in accordance with the invention includes a housing containing a radio receiver including a directional antenna for receiving radio transmissions from the at least one radio transmitter; a display, which is electrically coupled to the receiver and fixed in position with respect to the housing, for visually displaying a strength of the radio transmissions received by the directional antenna; and a field of view limiter for limiting light emanating from the display to a field of view of the display when a user holds the receiver unit in the user's hand away from the body of the user, the field of view being limited to planes extending upward from a plane of sight extending from the eyes of the user downward and intersecting a horizontal plane extending from the user's waist substantially at arms length of the user.

RF current-sensing coupled antenna device

Abstract: An apparatus for, and method of, replacing conventional antennas which intercept radio frequency fields and develop electrical signals for input to an RF receiver. The invention eliminates the use of antennas by taking advantage of the fact that any electrical conductor or surface develops significant current when its length is approximately 0.1 wavelength long or longer of an intercepted RF field. The RF current-sensing coupled antenna device, employing the principles of an instrument transformer, transforms the current in a wire filament or metallic surface and conveys it to a receiver. The useful frequency range that has been demonstrated for the coupled antenna device is 100 kHz to 2 GHz.

Method and apparatus for nondisruptively measuring line impedance at frequencies which are relatively close to the line frequency

Abstract: Impedance of an energized electrical line which carries electrical current at a predetermined line frequency is nondistruptively measured at frequencies which are above and below the predetermined line frequency. A measurement current is generated at a measurement frequency between, for example, 10 Hz and 30 kHz for a 60 Hz line. The current generator is coupled to the energized electrical line by an isolating circuit which blocks only the predetermined line frequency and frequencies which differ from the predetermined line frequency by substantially less than the predetermined line frequency. For example, a notch filter may be used. A current sensor measures the line current in the energized line at the measurement frequency. A voltage sensor measures the line voltage in the energized electrical line at the measurement frequency. An analyzer determines impedance of the energized line at the measurement frequency. The measurement is repeated over a wide range of frequencies above and below the line frequency. Preferably, the current sensor and voltage sensor use the same current sensor to cancel errors. Improved nondisruptive line impedance measuring is thereby provided.

Radio transceiver with impedance matched test port

Abstract: A radio transceiver is provided for wireless communications, having an interface connection that is selectable between either an antenna or a cable interface. The radio transceiver is engaged to the antenna through an impedance matching network which translates the antenna impedance to match that of the radio transceiver. The radio transceiver can, alternately, be connected to external test equipment or performance enhancement equipment through the cable interface. Since the radio transceiver has the same impedance as most external test equipment, the antenna matching network is not required or used when test equipment is connected to the cable interface. In the present invention the cable interface at least partially disconnects the matching network whenever the cable interface is in use. Once the antenna has been disconnected, the impedance of the cable interface matches that of the radio transceiver. Thus, the radio transceiver provides a convenient cable interface that matches the impedance of most test equipment, yet is easily switched to normal transmit/receive operation.

Thin broadband microstrip antenna

Abstract: An elementary antenna embodies a constant thickness dielectric substrate having on one side a conductive metal layer forming a ground plane and on its other side a radiating patch electrically connected to a feed line. The patch is formed by a conductive loop of constant width l surrounding an inner parasitic patch which is not fed and is separated from the inner parasitic patch by a closed continuous slot of constant width e adapted to bring about coupling between the loop and the inner parasitic patch.

New Inductive rf Discharge Using an Internal Metal Antenna.

Abstract: In conventional ICP (or TCP) reactors, a rf power is inductively coupled to an antenna placed outside a plasma vessel. Such an external coupling system is known to have several disadvantages. In order to avoid these disadvantages, a new internal coupling system has been developed in which a bare metal antenna is directly immersed in a plasma, thus forming a full metal reactor. This is accomplished by generating magnetic field lines around an antenna conductor, which effectively suppress the electron loss at the antenna and hence suppress the anomalous rise of plasma potential. Magnetic fields near the antenna are formed by superposing a dc current on a rf current along the antenna. This type of ICP enables rf discharges at rather low pressures such as ~3×10-4 Torr due to the magnetron effect. Other characteristics of internal metal antennas are also discussed.

Multi-antenna scanning diversity system

Abstract: A multi-antenna scanning diversity system uses an antenna diversity circuit adjacent to the antenna terminals, but remote from the receiver, whose input sees the antenna signals (A1) through (AN) and whose output provides a received signal selected by the diversity processor which then goes to the radio receiver via an bidirectional transmission line. The diversity circuit is also fed the radio receiver's IF signal scanned for interference by the diversity processor. In case of critical interference due to unfavourable reception conditions, the processor generates a switch signal causing another antenna to be selected. The system uses one common bidirectional transmission to conduct the RF signal from the diversity circuit to the radio receiver and the IF signal from the radio receiver back to the diversity circuit. By a of particular selectivity apparatus the system takes care of preventing the bidirectional transmission signal transfer on the common transmission line to degrade the function of the multi-antenna scanning diversity system.

Minimizing signal reflection along a transmission line without terminating the transmission line

Abstract: In a data transmission system having a first and a second data transmission device and a transmission line that is not terminated, a method of minimizing signal reflection along the transmission line is described that includes the step of connecting the first and second data transmission devices to the transmission line such that the distance between the first and second data transmission devices is substantially proportional to a wavelength of a predetermined frequency. Data to be transmitted from the first data transmission device to the second data transmission device via the transmission line are encoded in the first data transmission device such that energy of the encoded data is substantially concentrated around the predetermined frequency to minimize the signal reflection without terminating the transmission line. A data transmission system with minimized signal reflection is also described.

Integrated diplexer-amplifier for near antenna installation

Abstract: There is disclosed an integrated diplexer-amplifier for near antenna installation apparatus that routes amplified microwave signals in two different directions at the same time from RF input signals derived from two different sources. The apparatus makes use of four microwave bandpass filters arranged in a dual diplexer configuration and the amplifiers are connected such that RF signal gain in both directions is achieved, thereby eliminating the undesired losses associated with a coaxial cable such as that connected between a transceiving station and antenna. The apparatus is designed to be mounted on an antenna support, or a structure near to the antenna, in order to make up the RF signal loss of coaxial cable connections. Preferably the apparatus incorporates combline bandpass filters which pass essential fundamental signals only, providing high isolation between transmit and receive signals, while providing a grounded, connection to unwanted signals and DC current, thereby enhancing protection against lightning caused voltage damage. The apparatus permits the use of low cost, high loss, coaxial cable for connecting a transceiver system to an antenna.

Antenna for use with a radio installed in an expansion slot of a computer system

Abstract: An antenna that may be retrofitted for incorporation in an internal compartment of a computer terminal when a radio transmitter or receiver is installed in an expansion slot of the computer terminal. The present invention provides a radio receiver/transmitter communication system for a computer terminal. The computer terminal includes an expansion slot operative to receive a radio transmitter or receiver and includes an enclosed compartment defined in the housing of the computer terminal. The enclosed compartment is separate from the expansion slot. The radio receiver/transmitter communication system includes a printed circuit board and a radio frequency communication medium. The radio frequency communication medium is etched on a first side of the printed circuit board, thereby forming a circuit board antenna, and the printed circuit board antenna is positioned within the enclosed compartment of the computer terminal. The radio communication system also includes a radio transmitter/receiver expansion board installed in the expansion slot and a connection cable connected to and providing a transmission path between the radio frequency communication medium of the circuit board antenna and the radio transmitter/receiver. The radio communication system is preferably implemented in a portable computer terminal that includes a the stylus pen slot as an internal compartment.

Radiating device for a plannar antenna

Abstract: A radiating device for a planar antenna, said device including a first ground plane and a second ground plane, a slot (25) provided in the first ground plane and being fed by electromagnetic coupling from a feed line (17), and an assembly of a plurality of thin conductive parts; the central portion of the radiating slot (25) being a conductive part (15) supported at its center by a supporting column (18). Application in particular to the space field.

Multi-resonance antenna device

Abstract: PURPOSE: To attain multi-resonance without using any multi-resonance matching circuit and to provide a satisfactory directivity and both polarization radiation characteristics in the direction along a wall when the device is mounted on the surface of the wall. CONSTITUTION: This antenna device is a loop antenna folded in a U-shape, and both parallel parts 1a, 2a of an L-shape element and a center element 3 are set at λ/2 (λ: fundamental resonance wavelength of antenna), and orthogonal parts 1b, 2b are set at λ/4. The terminal part of the orthogonal part 1b is connected to a coaxial feed line 6, and that of the orthogonal part 2b to a ground metallic plate 5. An L-shape branch element 4 (or linear branch element 4') is connected to a point within 0.3λfrom the center element 3 or an L-shape element 2 on its extension, therefore, a second resonance frequency different from a reference resonance frequency is set. The length of the branch element is decided depending on the size of the element. Further multi-resonance can be obtained by increasing the number of branch elements.

Signal transmitting device suitable for fast signal transmission including an arrangement to reduce signal amplitude in a second stage transmission line

Abstract: A signal transmitting device includes a transmitting circuit block having a driving circuit connected to a main transmission line for driving a signal and an intra-block transmission line for transmitting a signal sent from the driving circuit to the main transmission line. The device also includes a receiving circuit block having a transmitting/receiving circuit connected to the main transmission line for receiving a signal inputted from said main transmission line and outputting the received signal to a next stage, an intra-block transmission line for transmitting a signal input from the main transmission line to the transmitting/receiving circuit, a receiving circuit for receiving an output signal from the transmitting/receiving circuit, and a next state intra-block transmission line to enable high-speed signal transmission, the main transmission line includes a termination resistor having s resistance equal to an impedance of the main transmission line and the intra-block transmission line includes an element having a resistance substantially equal to a value derived by subtracting a half of the impedance value of the main transmission line from an impedance value of the intra-block transmission line also, to improve transmission speed along the next-stage intra-block transmission line, a termination resistor is provided from the next-stage intra-block transmission line and the transmitting/receiving circuit and the next-stage intra-block transmission line to produce a voltage drop thereacross.

Low intermodulation electromagnetic feed cellular antennas

Abstract: A dipole array antenna is configured for improved cellular operation by avoidance of metallic contacts which can lead to generation of intermodulation products (IMP). Isolated rectangular dipole radiators 12-17 are electromagnetically excited by perpendicularly aligned non-contacting exciter resonators 40-45. The rectangular exciter resonators 40-45 are integrally formed with microstrip signal distribution feed 18 supported above a ground plane 22. A non-contact RF grounded termination for the outer conductor of coaxial input line 52 uses a quarter-wave microstrip line section 56 to provide a low impedance RF path to ground to avoid IMP. An RF-isolated DC grounding circuit for surge protection includes a parallel combination of quarter-wave line sections 62 and 66. Line section 66 provides an RF open circuit path to a DC grounding post 67. Line section 62 provides a parallel non-contact low impedance RF path to ground, avoiding IMP from flow of an RF current through pressure contact points at post 67. The low impedance RF path to ground through line section 62 is isolated from the signal distribution line 18b of the antenna by the RF open circuit provided by quarter-wave line section 68.

Rotary microwave antenna system

Abstract: A rotary microwave antenna system suitable for satellite or cellular microwave radio telecommunications features an integrated, low-profile, rotary microwave joint, slip ring and antenna assembly. The rotary antenna system includes a stator (i.e., stationary portion), for attachment to a mobile platform (e.g., an automobile or other vehicle), having a rotary joint coaxial microwave coupler for electrically coupling a microwave transmission line from a microwave telecommunications radio system to a microwave antenna element of an microwave antenna rotatable about an axis relative to the mobile platform. The rotary antenna system also includes a rotor (i.e., rotary portion) for attachment to the microwave antenna. The rotor includes a slip ring circuit (or brushes) for coupling power and low frequency electrical signals to the microwave antenna through contacting brushes (or slip ring) attached to the stator, rotates relative to the stator, and is concentric with the axis of rotation of the microwave antenna. The stator includes a disk having a peripheral edge around its circumference, and the rotor includes an annular ring having an inner edge around a central opening and a peripheral edge around its circumference. The inner edge of the rotor is adjacent to, concentric with, and rotatably coupled to the peripheral edge of the central disk by means of an assembly of ball bearings placed between the two adjacent edges.

Cavity-model analysis of a slot-coupled cylindrical-rectangular microstrip antenna

Abstract: An equivalent circuit of a slot-coupled cylindrical-rectangular microstrip antenna is constructed by describing the patch admittance seen at the slot position using the cavity-model method and calculating the slot self-admittance simply from a short-circuited slot line. An impedance transformer is also introduced in the circuit to transform the patch admittance and the slot self-admittance into a series load as seen by the feed line. The input impedance of the antenna is then readily obtained. Typical numerical results of the input impedance are presented and discussed. © 1995 John Wiley & Sons, Inc.

Design and analysis of slot array antennas on a radial feed line

Abstract: Antennas based on narrow slots directly coupled to a radial line have been used previously in direct broadcast satellite (DBS) receivers and reported by Ando (1985, 1990). One of the most important features for such antennas is their low cost and low loss feeding line, making it ideal for DBS (11.7 to 12.5 GHz operation). Most of the designs reported are based on experimental work or at least no systematic design procedure have been shown. This paper shows an easy design procedure based on the analysis of several narrow slots coupled to the line. A final, more accurate analysis can be done for the complete antenna including the coupling effect between slots.

Base station equipment using diversity reception

Abstract: not available for EP0715786Abstract of corresponding document: GB2281478A base station in a duplex radio communication system comprises two transceivers 10, 12 each of which has a transmitter 14, 20, a main receiver 16, 22 and a diverse receiver 18, 24. A main antenna 26 is connected to the common port of a first diplex filter 38, and a diverse antenna 28 is connected to the common port of a second diplex filter 40. A first amplifier and splitter 30, 32 feed main receive signals from the main antenna 26 to the main receivers 16, 22 and a second amplifier and splitter 34, 36 feed diverse receive signals from the diverse antenna 28 to the diverse receivers 18, 24. The diverse antenna 28 acts not only as a receive antenna, but also transmits signals from the transmitter 20, so more power is available for transmission.