Showing papers on "Feed line published in 1992"

Microwave reflection resonator sensors

Abstract: A highly sensitive, direct-contact, in situ sensor for nondestructively measuring or monitoring the complex dielectric and conductive properties of solids, liquids, or gasses at microwave frequencies. A metal microstrip dipole resonator (11) is etched on the surface of a dielectric substrate (12) which is bonded to a copper ground plane (14). The dipole resonator is electromagnetically driven by mutual inductive coupling to a short nonresonant feed slot (13) formed in the ground plane (14). The slot (13) is driven by a coaxial feed line (7) or a microstrip feed line (16) extending from a swept microwave frequency source (2) which excites the incident wave (17). Alternatively, the metal resonator is omitted and the length of the slot (15) is increased so that it becomes the resonator. In use, the sensor is placed in close physical contact with the test material (9) having complex dielectric constant e* (=e'-je") or conductivity σ. As the frequency of the microwave source (2) is swept, a sharp dip in the reflected wave (18) occurs at the resonant frequency, provided that the coaxial feed line (7) or microstrip feed line (16) is nearly critically coupled to the sensor input. Measurement of the resonant frequency and input coupling factor determines small changes in e', e" and σ with great resolution. To diminish the electromagnetic coupling between the resonator (11) and the test material (9), and to protect the resonator (11) from damage and wear, a superstrate (26) may be added.

Power line filter

Abstract: A noise induced from a switching power supply source or the like is applied to a power line. The noise is classified into two kinds, one of them being normal mode noise appearing between power lines and the other one being common mode noise appearing between a power line and a ground line. Thus, a line filter is required to attenuate these noises. The present invention provides a line filter for attenuating normal mode noise appearing on a power line between a live line and a neutral line as well as common mode noise appearing between the power line and a ground line, wherein the line filter includes a plurality of first inductors interposed between the live line and the neutral line, a first X-capacitor interposed between the live line and the neutral line on the load side relative to the first inductors, a plurality of second inductors interposed between the live line and the neutral line on the load side relative to the first X-capacitor, and a Y-capacitor interposed between the live line and the ground line as well as between the neutral line and the ground line on the load side relative to the second inductors, the Y-capacitor constituting a common mode filter between the first inductors and the second inductors in response to common mode noise.

Integrated radio receiver/transmitter structure

Abstract: A single chip receiver/transmitter section (202) includes an antenna switch (208), a low noise amplifier (210), a power amplifier (212) and a first (214) and second (216) mixers. The antenna switch (206)includes an antenna terminal (256) which is coupled to an off-chip band pass filter (206) which provides all of the selectivity for radio (200). Also described is a transmitter/receiver structure (300) which incorporates a transmission line filter such as band pass filter (206) formed by substrates (304) and (306) and includes the single chip transmitter/receiver section (202) imbedded inside of the structure (300).

Method and apparatus for dual-channel diversity reception of a radio signal

Abstract: A data communication receiver (100) includes a first antenna feed (106) coupled to a first receiver element (110) for demodulating (502) a radio signal containing data bits and for deriving a first phase-locked loop error signal. The data communication receiver (100) also includes a second antenna feed (108) coupled to a second receiver element (112) for demodulating (502) the radio signal and for deriving a second phase-locked loop error signal. A received signal strength indicator (134, 144) measures signal strength of the radio signal from the first antenna feed (106) during reception of a data bit, and concurrently measures signal strength from the second antenna feed (108). A processor (146) then defines (506, 508, 512) the data bit as received from the antenna feed (106, 108) having the greater signal strength to be the optimum data bit.

Directional microstrip antenna with stacked planar elements

Abstract: A monolithically loaded microstrip antenna is provided for a communications function, such as a cellular telephone base station. The antenna includes a ground plane and a group of stacked, planar elements. A director element having a rectangular configuration together with monolithic load tabs is connected to a feed line and spaced above the ground plane. A first director element is spaced above the driven element and has lesser length and width dimensions than the driven element. A second director element is spaced above the first director element and likewise has lesser length and width dimensions than the driven element. A group of eight of the antennas are positioned in a column to form an antenna array which has substantial vertical polarization, a relatively wide horizontal beam width, approximately 60° and a relatively narrow vertical beam width, approximately 8.0°. The antenna array has a center frequency of 885 Mhz and a bandwidth of approximately 230 Mhz.

Embedded antenna for communication devices

Abstract: A radio communication device (300) having a display terminal (100) includes a glass portion (102) with an antenna (108) deposited thereon. The radio communication device (300) also includes a receiver (408) for receiving a radio communication signal. Radio communication signals are coupled to the receiver (408) via the antenna (108). In another aspect of the present invention, the radio communication device (300) includes a metal frame (206) which operates as its antenna and secures the display terminal (204) to the radio communication device (300).

Feeding structure contribution to radiation by patch antennas with rectangular boundaries

Abstract: A combination of piecewise sinusoidal-pulse functions and semi-infinite microstrip current expansion functions is used in the full-wave spectral-domain method to analyze microstrip antennas with arbitrary rectangular boundaries. Radiation properties are formulated in the spectral domain to achieve high numerical efficiency. Two types of microstrip antennas, edge-fed rectangular and inset fed patches, have been analyzed and measured. A line-reflect-line de-embedding algorithm has been implemented to measure the input impedance of both antennas. The results show good agreement between measurement and calculated data. The radiation patterns from the edge-fed rectangular patch are measured and are compared with the theoretical data. Results show that the current on the feed line can disturb the antenna radiation pattern. >

Feed circuits of double-layered self-diplexing antenna for mobile satellite communications

Abstract: An analysis of feed circuits for a double-layered self-diplexing antenna for mobile satellite communications is presented. It is possible to reduce the weight of the diplexer for a self-diplexing antenna by getting large internal isolation between transmitting and receiving. The internal isolation is shown to be heavily dependent on the configuration and errors of the feed circuits of the antenna. The feed circuits of two- and four-point feeds for the antenna are discussed, using the cavity model of microstrip elements, and an error analysis of the feed circuit is carried out. >

Combined coaxial connector and radio frequency switch assembly

Abstract: An antenna connector and RF switch assembly (10) is provided on a portable radio (14). The radio includes a self-contained antenna (16) and a radio circuit (27). The assembly (10) is used for selectively connecting the radio circuit (27) to the antenna (16) or to an external signal supply (39). In the assembly, a switchable conductive center contact portion (22, 20, 35) selectively engages either the antenna (16) or the external signal supply (39). A metallic housing (18), having an antenna bushing (17), receives the antenna (16). A molded dielectric insulator portion (26) separates the switchable conductive center contact portion from the metallic housing and is directly connected to the antenna bushing.

Array antenna generating circularly polarized waves with a plurality of microstrip antennas

Abstract: A microstrip antenna is disclosed which comprises a ground conductor plate and a patch opposed to the ground conductor plate with a particular distance, a transmission feed line and a reception feed line being disposed between the ground conductor plate and the patch. Signals are fed from these feed lines to the patch by electromagnetic coupling. The angle made by the extended lines of these feed lines is nearly 90°. When four patches are disposed in a square arrangement, the transmission feed line feeds signals in directions of first lines which pass through the center point of each patch in such a way that the directions are line-symmetrical with respect to a horizontal line and a vertical line which pass through the center point of the square arrangement. On the other hand, the reception feed line feeds signals in the directions of second lines which pass through the center point of each patch and intersect with each first line at right angle. As a result, the mutual coupling between transmission and reception can be suppressed to a low level. In addition, when the transmission feed line is radiately connected from the center point of the square arrangement to each patch, the length thereof can be reduced, thereby decreasing the transmission loss.

Flat-plate antenna with strip line resonator having capacitance for impedance matching the feeder

Abstract: A flat-plane antenna for mobile communications, used in automobiles, etc. including a table form antenna element made up of a conductive flat-plate section and a plurality of leg sections which connect to the flat-plate section to a ground plate, a strip line resonator provided beneath the table form antenna with a space in between, and a capacitor electrode provided on the strip line resonator directly under the center of the table form antenna element. A feeding line is connected to the strip line resonator.

Wideband transmission line balun

Abstract: A wideband transmission line balun divides an input signal equally between a single-conductor transmission line and a polarity reversing, two-conductor transmission line thereby providing balanced signals at the transmission line outputs. Simple printed circuit and shielded structures include a ferrite core interactive with the two-conductor transmission line for parasitic mode suppression.

Feeding system and feeding method for a submarine cable communication system

Abstract: A feeding system is provided for supplying a current to repeaters on a communication cable including a feed line for conducting a current to the repeaters. The feeding system includes a plurality of branching units provided on the communication cable and terminal stations each being connected through at least one of the repeaters to one of the branching units, and each of the terminal stations feeding a current through the feed line to the repeaters. In addition each of the plurality of branching units includes at least one switching circuit for switching to connect the at least one of the repeaters to the communication cable or to the ground, depending on the amount of current conducting through the feed line in the communication cable. Further, the current thresholds of the switching circuits in the plurality of branching units are preferably different from each other.

Radiated emission from shielded cables by pigtail effect

Abstract: Theoretical analyses and experimental results are carried out on the common mode radiated emission from a shielded cable caused by pigtails. Calculations of the radiation are introduced on the basis of transmission line theory and antenna theory, and are in excellent agreement with the experiment. Certain protective methods and techniques are presented, which exhibit at least 30-dB suppressions against the pigtail effect. >

Notched nested cup multi-frequency band antenna

Abstract: A cavity (12,14) with a plurality of notches (16,18,20,22) formed in the edge of the open end. Each notch is fed to establish a notch-type antenna. Notches at 90° angles from each other are formed for a monopulse application. A coaxial feed line (30,32,34,36) is used where the outer conductor is connected at one side of the notch and the inner conductor at the other side. The sizes of the cavity and notches are selected to radiate energy of a selected frequency bandwidth. Additional cavities (48,50,52) of different sizes for radiating different selected frequencies are nested concentrically together to form a multifrequency antenna array with a common phase center. Each cavity has a plurality of notches and each cavity may be rotated in relation to the adjacent cavity to misalign the notches between the two cavities and thereby increase isolation between frequency bands.

A novel dual antenna measurement of the angular distribution of received waves in the mobile radio environment as a function of position and delay time

Abstract: A dual antenna experiment to estimate the angular distribution of received waves in a mobile radio environment as a function of position and delay time at 2.3 GHz using a Cox-type channel sounder is described. The two receive antennas had a transverse separation of 0.49 lambda . The test area is a mix of modern high-rise buildings and warehouses lined by expanses of water. No line-of-sight path exists between transmitter (30-m elevation) and the mobile receiver (2.6-m elevation). As the receiver moves, a two-dimensional grid of I and Q-responses from each antenna is recorded. The data are correlated offline with a reference pseudo-random binary sequences and then processes to give estimated 360 degrees plots of the incident power's angular distribution at different delay times. This information is useful for the design of adaptive array antenna diversity systems. >

Broadband gap-coupled microstrip antenna arrays

Abstract: In order to increase the bandwidth of microstrip antennas, an antenna array using gap-coupled patches as the elements is proposed. The input impedance characteristics of gap-coupled patches are analyzed by the dyadic Green's function for a grounded dielectric slab and the moment method. The input impedance of gap-coupled patch arrays is by combination with the antenna elements and the feed network that consists of divider tees, bends and feed line. In addition, considering the surface currents solved from the integral equation, the far field patterns of gap-coupled patch arrays are calculated. Comparison with the ordinary rectangular patch arrays is made. It turns out that the impedance bandwidth for a voltage standing wave ratio of less than 2 of the two-element gap-coupled patch array is much wider than that of the ordinary patch antenna array. All microstrip antennas have been designed and fabricated on substrate with in /sub r/=2.86, h=1.5 mm. >

A microshield line loop antenna for sub-mm wavelength applications

Abstract: A new type of antenna fed by a monolithic planar transmission line is presented. The antenna is formed as a resonant slot loop which is fed by a recently introduced microshield line. The design offers low spurious radiation from the feed line and low-loss power transmission in the feed network. The antenna design is applicable at frequencies in the millimeter and sub-millimeter wavelength region using thin dielectric or membrane technology. The predicted radiation pattern at resonance and input impedance as a function of frequency demonstrates the performance of the new antenna. >

Concealed radio transmitter in a tapemeasure

Abstract: According to the invention there is provided a concealed radio transmitting device which includes a radio transmitter, an antenna coupled to the radio transmitter, power supply for supplying electric power to the transmitter, an on/off device connected between the power supply and the radio transmitter, and a housing shaped as a tape measure adapted for containing the radio transmitter, the antenna, the power supply and the on/off device, and wherein further the concealed radio transmitting device includes in the radio transmitter an audio input, and a microphone connected to the audio input for transferring audio signals to the transmitter.

Radio transmitting system having back-up radio receiver operable in response to failure of main feed line

Abstract: A radio calling system includes a central control station simultaneously broadcasting a calling signal of an arbitrary pager terminal, and a plurality of radio transmitting stations coupled to the central control station. The plurality of radio transmitting stations simultaneously transmit the calling signal received from the central control station at the same radio frequency. The calling signal transmitted from the radio transmitting stations reach the arbitrary pager terminal and at least a neighboring one of the radio transmitting stations. At least an arbitrary one of the radio transmitting stations includes a first relay for relaying the calling signal received from the central control station, a second relay which has a receiver part for receiving the calling signal transmitted from a radio transmitting station other than the arbitrary radio transmitting station, and a storage relay part for storing the calling signal received by the receiver part and for transmitting the stored calling signal during a time in which no transmission is made by the radio transmitting stations other than the arbitrary radio transmitting station. A switching circuit coupled to the first and second relays carries out switching to enable one of the first and second relays, depending on whether or not a communication failure exists between the central control station and the arbitrary radio transmitting station.

Schreibgeraet mit in einem behaelter frei aufgenommener schreibfluessigkeit

Abstract: The proposal is for a writing device (10) comprising a reservoir (11) with an aperture (12) in which the writing fluid (13) is freely held and an at least partially capillary feed line (14) for the writing fluid (13) which connects the reservoir (11) to the writing head to feed writing fluid (13) and a capillary store connected to the feed line (14). The feed line (14) fills the aperture (12) and is in direct contact with the capillarity store (16), whereby the capillary of the capillarity store (16) is on average lower than that of the feed line (14), at least in the aperture (12) of the reservoir (11).

Transmission line length measurement method and apparatus

Abstract: By measuring the waveform of the reflected wave (RF) obtained by transmitting a pulse (RF) to the open-ended transmission line (100), a transfer function of the transmission line with respect to the incident wave (RF) is computed as a result of the measurement. Then, the waveform of the output wave at the output end or the open end of the transmission line is estimated in response to an individual input signal (RF) by using the transfer function computed. The transmission delay time (T) of the transmission line is obtained by computing the time difference (2T) between the transient timing (b) of the estimated waveform of the output wave (RF) and the transient timing (a) of the waveform of the input signal (RF).

Simple transmission line feed model for microstrip antennas in two-sided structure with coaxial probe coupling

Abstract: A simple transmission line feed model is presented for micro-strip antennas in a two-sided structure coupling through a coaxial probe. The parameters of the model are extracted directly from the feed structure. The validity of the feed model combined with the recently developed transmission line model of microstrip antennas is verified by measurement.

Analysis and development of signal injection technique using transmission lines embedded at phased array aperture

Abstract: The authors present an analysis of electromagnetic coupling between a twin-lead transmission line and a dipole element. The computed coupling value was verified by the measurement of the coupling between a single-wire transmission line and a monopole above a ground plane. An analysis of the coupling between a transmission line and a linear array of dipole elements over a ground plane was also developed. An experiment involving the measurement of the coupling between a single-wire transmission line and a linear array of monopoles in a parallel-plate waveguide was performed. The measured data compared favorably with the calculated data. >

Higher order modes in microstrip antenna design via the transmission line model

Abstract: A coaxially fed microstrip antenna is analysed by using the transmission line model. The excited field under the patch is Fourier decomposed into its modal components. The influence of the higher order modes on the impedance behaviour and far field patterns is shown and illustrated for a particular antenna.

Computation of RF Fields for Applicator Design

Abstract: A 2-dimensional solver for the complex scalar Helmholtz equation has been developed. This code can be used to solve for the RF field distribution in microwave applicators that have large dielectric or permeability losses and to determine the VSWR on the feed line to the applicator. It also solves the complex eigenvalue problem for cavities containing lossy materials. Some examples °fits use in both types ofapplication are given.

Evaporation cooling system for IC engine - includes cooling jacket filled only partly with liq. coolant and at least one condenser with its lowest point lying above highest allowed coolant level in engine

Abstract: A connecting line (4) is led from the highest point of the cooling medium system to the radiators (5,6). A return line (8) is led from the radiators to the lowest point in the cooling medium (2) system. An expansion vessel (10) is integrated in the cooling system. An electrically driven cooling fan is provided. The expansion vessel (10) is connected to the return line (8) across a feed line (9). The feed line opens out in to the expansion vessel, as a suction line with a rising mouth section (12). The mouth of the feed line in the vessel ends above the highest water level in the cooling medium system, with a cold engine. With a cold engine, the expansion chamber is filled with coolant (2) up to the mouth of the feed line (9). ADVANTAGE - System manages with few components.

RF crossover network

Abstract: A RF crossover network includes a RF line, a DC/control line capacitively coupled to the RF line at a crossover of the RF line, and RF terminations coupled to the DC/control line. A RF signal carried on the RF line is unperturbed by the presence of a DC/control signal on the DC/control line. The RF line is mounted on a first dielectric layer including a ground plane. A second dielectric layer includes first and second surfaces with the DC/control line mounted on the first surface of the second dielectric layer and the second surface of the second dielectric layer positioned adjacent to the RF line. RF terminations are used on opposite ends of a half wave resonator. The RF terminations can comprise shunt capacitors, metal-insulator-metal (MIM) capacitors in a monolithic microwave integrated circuit (MMIC) embodiment, or open-circuited quarter wavelength transmission lines.

Feeding method and feed line switching circuit for sea-bottom cable communication system

Abstract: PURPOSE:To prevent hot switching and to switch a feed line at the time of reconstructing the feed line when a fault occurs. CONSTITUTION:Respective sea-bottom branching devices BU1, BU2... are provided with feed line switching circuits in which the size of an operation current differs by changing the direction of the current. The feed line switching circuits of respective sea-bottom branching devices BU1, BU2... are constituted so that respective operation current values alpha, beta... differ as against the same feed current direction in both end feed line which is to be set. In a station on the side of a non-fault line on the side of a fault-side sea-bottom branching device to which the both end feed line is to be set and a station on the side of a non-fault-side sea-bottom branching device, feeding is executed in the feed current direction where the feed line switching circuit in the fault-side sea-bottom branching device operates with the small operation current and the feed line is switched so that the fault line is separated. Then, the large feed current is fed in the same feed current direction, the feed line switching circuit in the non-fault-side sea-bottom branching device is switched and the feed line is set at the time of raising a system when the fault occurs.

Radio frequency optical transmission method and communication equipment applied with the method

Abstract: PURPOSE:To provide a transmission line design method for the radio frequency optical transmission line. CONSTITUTION:A line hit rate P is prepared in advance and a carrier versus noise ratio required for an optical link is calculated by the line hit rate P and the level PRF, of a radio frequency signal is automatically gain- controlled so as to keep the carrier versus noise ratio . Thus, the desired quality of the communication is secured. Furthermore, the carrier versus noise ratio is estimated smaller than that of a conventional method. Thus, the existing optical transmission technology is applied to the radio frequency optical transmission system.