Showing papers on "Feed line published in 2001"

Single or dual band parasitic antenna assembly

Abstract: A compact single or multiple band antenna assembly for wireless communications devices. One multi-band embodiment includes a high frequency portion and a low frequency portion, both fed at a common point by a single feed line. Both portions may be formed as a single stamped metal part or metallized plastic part. The overall size is suitable for integration within a wireless device such as a cell phone. The low frequency portion consists of two resonant sections which are stagger tuned to achieve a wide resonant bandwidth, thus allowing greater tolerance for manufacturing variations and temperature than a single resonant section, and is useful for single band antennas as well as multi-band antennas where it may be used to enhance bandwidth for both sections of a dual band antenna as well. The resonant sections for single or multi-band antennas operate in conjunction with a second planar conductor, which may be provided by the ground trace portion of the printed wiring board of a wireless communications device. The antenna assembly provides a moderate front-to-back ratio of 3-12 dB and forward gain of +1 to +5 dBi. The front to back ratio reduces the near field toward the user of a hand held wireless communications device, thus reducing SAR (specific absorption rate) of RF energy by the body during transmit. The antenna pattern beam width and bandwidth are increased for a handset during normal user operation, as compared to a half wave dipole.

RF signal detector circuit with reduced sensitivity to transmission line impedance mismatches

Abstract: An RF signal detector circuit and a method for monitoring the level of Radio Frequequency signals flowing through a trasmission line are disclosed. The RF detector circuit comprises: a first RF coupling device (181) connected to a transmission line (12) for receiving RF samples; and a first RF detector (201) responsive to an output of the RF coupling device (181). It is characterized in that it also comprises a further RF coupling device (182); and a further RF detector (202) responsive to said further RF coupling device (182), both said RF coupling devices (181, 182) being connected to the transmission line and placed at a distance ( I C ) from each other that is an odd multiple of one-quarter of wavelength λ.

The dependence of the input impedance on feed position of probe and microstrip line-fed patch antennas

Abstract: The impedance of a rectangular patch antenna fed by an inset microstrip transmission line was measured for various feed positions. The dependence found was then compared to theoretical predictions both for this geometry and for the similar case of an inset coaxial probe feed.

A 915-MHz antenna for microwave thermal ablation treatment: physical design, computer modeling and experimental measurement

Abstract: A 915-MHz antenna design that produces specific absorption rate distributions with preferential power deposition in tissues surrounding and including the distal end of the catheter antenna is described. The design features minimal reflected microwave current from the antenna flowing up the transmission line. This cap-choke antenna consists of an annular cap and a coaxial choke which matches the antenna to the coaxial transmission line. The design minimizes heating of the coaxial cable and its performance is not affected by the depth of insertion of the antenna into tissue. The paper provides a comparison of results obtained from computer modeling and experimental measurements made in tissue equivalent phantom materials. There is excellent agreement between numerical modeling and experimental measurement. The cap-choke, matched-dipole type antenna is suitable for intracavitary microwave thermal ablation therapy.

Antenna circuit arrangement and testing method

Abstract: The invention concerns generally the technological field of planar antenna arrangements in portable radio devices. Especially but not exclusively the invention concerns inverted-F antenna arrangements. The invention also concerns a portable radio device equipped with such a planar antenna arrangement. And additionally the invention concerns a method for producing and testing a portable radio device comprising a planar antenna. One idea of the present invention is providing an aperture (322) in the radiator element (316) of the planar antenna. An RF test point (324) is also provided for aligning the RF electronics, and the RF test point is located in such a way related to the aperture of the radiator that the test signal (320) is easily led through the aperture. It is further advantageous that an RF switch (324, 326) is provided for coupling/decoupling a connection between the planar antenna and the RF electronics. In a preferred embodiment the RF switch is integrated with the RF test point. The inventive arrangement thus allows testing the RF electronics after the radiator plate (316) has been attached to the printed wired board (334).

Portable information terminal having wireless communication device

Abstract: In an information terminal, a coaxial cable connected a radio-circuit-board, which is often placed at a front section of a case, to an external antenna terminal or an antenna placed at a rear section of the case The terminal having a simple structure prevents a clock signal from leaking to the coaxial cable from a CPU, so that an S/N ratio in receiving can be improved A cable-groove recessed from a bottom to inside is provided The coaxial cable between the radio circuit board and the external antenna terminal or the antenna runs through the cable groove, which is covered with a lid Thus, a clock signal of the CPU can be shielded by the conductive case

Invasive therapeutic probe

Abstract: An invasive therapeutic probe assembly and related methods for application of RF energy to a volume of body tissue are provided. The probe assembly includes an RF source configured to provide an RF energy having selected characteristics, a probe having a probe shaft and an antenna (18) positioned therein, and a feed line (20) for providing conductivity from the RF source to the antenna (18) probe. The probe assembly is adapted to generate a zone of therapeutic effectiveness having a selected geometry and volume. The related method includes positioning the probe in a selected location with reference to a target tissue, initiating an electromagnetic field from the antenna (18) having a selected geometry, and producing a zone of therapeutic effectiveness having a selected geometry and volume. The producing step preferably includes, taking periodic temperature measurements from sensors positioned at a selected location, and manipulating the selected characteristics of the RF energy to include duration and/or power level.

Radio communication apparatus, transmitter apparatus and receiver apparatus

Abstract: A radio communication apparatus, a transmitter apparatus and a receiver apparatus that are capable of dealing with a plurality of signal waves. The radio communication apparatus has a millimeter wave transmitter (15) and a millimeter wave receiver (29). The millimeter wave transmitter (15) includes a multiplexing circuit (1), a millimeter wave up-converter (4) and an antenna (3). The millimeter wave receiver includes an antenna (31), a millimeter wave down-converter (32) and an output processing circuit (45). User-only signal waves are modulated by modulator circuits (121-124) such that they are located between the terrestrial waves and the satellite waves. The modulated signal waves are multiplexed in the intermediate frequency band, then converted into a millimeter wave band, and then transmitted. On the receiver side, the multiplexed waves are frequency down-converted, then separated, and then demodulated.

Impedance matching circuit and antenna apparatus using the same

Abstract: One matching circuit ( 8 - 2 ) comprises a transmission line ( 6 b ) of a predetermined electrical length and a parallel resonance circuit ( 5 ) connected in parallel with the transmission line. The resonance circuit has a resonant frequency f 2 and a predetermined susceptance at a frequency f 1 lower than the frequency f 2 . ANother matching circuit ( 8 - 1 ) comprises a transmission line ( 6 a ) of a predetermined electrical length and a capacitor element (b 3 a ) connected in series with the transmission line between an input terminal ( 2 ) of an antenna ( 1 ) and the matching circuit ( 8 - 2 ) so that the input impedence of the antenna at the frequency f 2 may match the characteristic impedance of an external circuit ( 10 ).

Monolithic single pole double throw RF MEMS switch

Abstract: Apparatus for a micro-electro-mechanical switch that provides single pole, double throw switching action. The switch comprises a single RF input line and two RF output lines. The switch additionally comprises two armatures, each mechanically connected to a substrate at one end and having a conducting transmission line at the other end with a suspended biasing electrode located on top of or within a structural layer of the armature. Each conducting transmission line has conducting dimples that protrude beyond the bottom of the armature carrying the conducting transmission line. Closure of an armature causes the dimples of the corresponding conducting transmission line to mechanically and electrically engage the RF input line and the corresponding RF output line, thus directing RF energy from the RF input line to the selected RF output line.

Antenna with a conductive layer and a two-band transmitter including the antenna

Abstract: The antenna of said transmitter is a microstrip antenna. A rear edge of its patch is provided with a short circuit by means of which a quarter-wave primary resonance can be excited by a coplanar line formed by two coupling slots in an area. Separator slots separate said area from another area in which a secondary resonance can be established at twice the frequency of the primary resonance from a slotted line extending one slot of the coplanar line. The invention applies in particular to the production of a dual-mode mobile telephone to the GSM and DCS standards.

Computer system, electronic circuit board, and card

Abstract: There are provided motherboard 7, signal line 12 formed on motherboard 7, multiple ground lines 13 formed spaced apart and substantially in parallel with each other adjacent signal line 12, card board 10, signal line 14 formed on card board 10, multiple ground lines 15 formed spaced apart and substantially in parallel with each other adjacent signal line 14, and line connector 9, and signal line 12 and signal line 14 are connected by conductor 16 in connector 9, while ground lines 13 and ground lines 15 are connected by conductor 17 in connector 9. Radio frequency module 11 is connected to signal line 14, and signal line 12 is connected to an antenna through radio frequency receptacle 8. A radio frequency signal is transmitted through signal line 12, conductor 16, and signal line 14 with a low insertion loss.

Dual band slot antenna with single feed line

Abstract: A dual band slot antenna (1) for an electronic device includes an antenna body (10) with elongated first and second slots (11, 12) defined therein and a coaxial feeder cable (20) having a conductive inner core wire (21) and a conductive outer shield (22). The inner core wire is electrically connected to the antenna body at an outer side of the first slot 11 and the outer shield is electrically connected to the antenna body at an opposite, outer side of the second slot. The coaxial cable acts as a common feed line of the first and second slots.

Combination linearly polarized and quadrifilar antenna

Abstract: A combination linearly polarized antenna and quadrifilar helix antenna (40) includes a quadrifilar antenna (49) having a first coaxial cable (46) and an antenna with linear polarization (44) external to the quadrifilar antenna and having a second coaxial cable (42). A center conductor of the second coaxial cable is isolated from a center conductor of the first coaxial cable and the first coaxial cable runs substantially concentrically through the antenna with linear polarization.

Analysis and network modeling of an aperture-coupled microstrip patch antenna

Abstract: This paper describes a method for analyzing an aperture-coupled microstrip patch antenna in order to develop an improved transmission-line model that reflects the effects of structure parameters, including inclination angles and offset distances of the aperture with respect to the feed line or the patch. The equivalent circuit consists of three ideal transformers, extended slotlines terminated by a short circuit, and microstrip transmission lines with open stubs. Two transformers are introduced to take account of the interaction between the aperture field and two orthogonal patch modes, while the third transformer reflects the coupling between the aperture and the feed line. The turn ratios of the transformers are calculated efficiently. The microstrip open stubs in the patch are then replaced by well-known capacitance and radiation conductance equivalents. The proposed transmission-line model is then applied to several variations and shown to produce accurate antenna impedances.

Patch antenna with finite ground plane

Abstract: A patch antenna is described with enhanced beamwidth characteristics. In a first embodiment, the antenna comprises a patch element and a ground plane separated from the patch element by a first dielectric layer. The antenna further includes a signal feed line separated from the ground plane by a second dielectric layer, the signal feed line being shielded from the patch element by the ground plane. The signal feed line is electromagnetically coupled to the patch element through an aperture in the ground plane lying across the signal feed line, the ground plane functioning as a finite surface relative to the aperture. According to a further aspect of the invention, the beamwidth of the antenna is adjusted by adjusting the position of a reflector behind the signal feed line. Thus, the present invention provides an efficient way to achieve adjustable wide-beamwidth for various wireless systems in a three-sector configuration.

Multiband planar antenna

Abstract: The present invention relates to a multiband planar antenna consisting of at least one resonator formed of an element having a closed shape made on a substrate and dimensioned so as to operate in its fundamental mode at the resonant frequency of the lowest band. The resonator is fed by a feed line in such a way as to operate in all the higher modes. The resonator comprises means for modifying the resonant frequencies of the various modes in such a way as to cover the bands concerned.

Patch antenna with embedded impedance transformer and methods for making same

Abstract: An antenna is described that comprises an antenna having a patch element fabricated onto a substrate, a ground plane, and an impedance transformer between the patch element and the ground plane. The patch element electrically connected to a first end of the impedance transformer, and a feed line is electrically connected to a second end of the impedance transformer through the ground plane. The use of the impedance transformer allows impedance matching to be accomplished without being limited by the physical limitations of the patch element. According to a further aspect of the invention, a patch element is fabricated onto a first substrate surface and a ground plane is fabricated onto a second substrate surface, the ground plane separated from the patch element by a plurality of substrate layers. An impedance transformer is embedded between abutting substrate layers between the patch element and the ground plane, and an electrically conductive via connects a first end of the impedance transformer to a feed point on the patch element. The antenna further includes a coaxial feed having an outer conductor electrically connected to the ground plane and an inner conductor electrically connected to a second end of the impedance transformer, such that a signal is carried between the coaxial feed and the patch element through the impedance transformer.

A low-cost microstrip-line-fed shorted-patch antenna for a PCS base station

Abstract: A low-cost microstrip-line-fed shorted-patch antenna suitable for applications in a PCS (1710–1880 MHz band) base station is presented. Both the shorted patch and the 50 Ω microstrip feed line have an air substrate, and the material cost is thus reduced to be minimum. And by using a pair of shorting plates of proper widths for shorting the radiating patch to the antenna's ground, the proposed antenna can be directly fed by the 50 Ω microstrip feed line, which greatly simplifies the antenna's impedance-matching design. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 146–148, 2001.

Simple design of dual-frequency unequal power-divider

Abstract: It is economical to have one base station antenna array for the dual-frequency operation of the mobile phones. From transmission line theory, it is shown that a power-divider can be made simply from a two-section transmission line transformer in each branch.

Matching circuit chip, filter with matching circuit, duplexer and cellular phone

Abstract: The present matching circuit chip has an integrated shape comprising a first transmission line, a second transmission line and a third transmission line, wherein one end of the first transmission line, one end of the second transmission line and one end of the third transmission line are connected to one another, a first filter connection terminal is connected to the other end of the first transmission line, an antenna terminal is connected to the other end of the second transmission line, and a second filter connection terminal is connected to the other end of the third transmission line, whereby the second transmission line converts the characteristic impedances of the first and third transmission lines so that the impedance matching between the antenna terminal and the first filter connection terminal can be attained, and so that the impedance matching between the antenna terminal and the second filter connection terminal can be attained.

Vehicle antenna assembly for receiving satellite broadcast signals

Abstract: An apparatus, system and method for providing audio broadcast signals received from a satellite to a satellite radio receiver. A window clip having an integral transmission line is mounted on the edge of a vehicle window. The interior end of the transmission line is connected to the satellite radio receiver. The exterior portion of the clip, and the exterior portion of the integrated transmission line, is coupled to an antenna. The antenna may be an omnidirectional quadrifilar antenna having circular polarization, a gain greater than about 3 dBi, a G/T greater than about −20 dB/K, and a frequency range of about 2.3 GHz to about 2.7 GHz, also known as the S-band. The antenna system can be used to receive satellite digital audio radio service (SDARS) and transfer the signal to a satellite radio receiver inside the vehicle.

Temperature-control apparatus for a printing machine

Abstract: A temperature-control apparatus for a printing machine includes a closed, temperature-control fluid circuit including a pump with a suction and pressure side, a fluid feed line feeding temperature-control fluid from a fluid source to the suction side of the pump and a fluid return line on the suction side of the pump between the pump and the load. Temperature-control fluid from the source may be pumped by the pump through the circuit to the load and recycled to the suction side of the pump. A valve is provided in the return line to the source and is controlled by a temperature sensor that senses the temperature in the circuit and selectively directs fluid to the circuit or out of the circuit and back to the source dependent upon the sensed temperature. A flow resistance is located in the temperature-control fluid circuit between the connection points of the fluid feed line and the fluid return line for creating a back pressure in the circuit and aiding the passage of fluid through or out of the circuit through the valve when opened.

Scanning, circularly polarized varied impedance transmission line antenna

Abstract: The present invention features a cross-element, steerable, scanning meander line loaded (MLA) antenna with circular polarization. The transmission lines comprise a plurality of alternating or stepped impedance sections with the high impedance elements acting as active antenna elements. The impedance varies depending upon the spacing from the moveable ground plane. The orthogonal MLA elements allow the application of an in-phase and a 90° shifted signal, thus each linear array radiates a circularly polarized RF signal. Controlling the spacing between the ground plane and transmission line provides relative phase control between the active elements and thereby phased-array directional control of the antenna. Forming a two-dimensional array of these linear arrays, produces a compact, low-cost, scanning, phased-array antenna.

Resonant optical modulators with zero chirp

Abstract: An external resonant optical modulator is provided by forming a waveguide electrode structure coupled to a coplanar strip or coplanar waveguide pattern including a ring resonator electrode and a ground electrode substantially surrounding the ring resonator electrode. These electrode patterns are disposed on an electrooptic substrate that includes an optical waveguide pattern. The waveguide electrode structure includes an RF feed line electrode coupled to the ring electrode. The RF feed line signal excites an inherent resonant mode of the ring to thereby cause an electric field to resonate between the ring electrode and ground electrode and pass into sections of the optical waveguide pattern. By appropriately positioning the ring and ground electrodes to overlay portions of the optical waveguide structure in the electrooptic substrate, a light beam launched into the waveguide pattern can be modulated to produce a pulse with zero chirp.

Transmission line to waveguide transition including antenna patch and ground ring

Abstract: Disclosed are planar structures for coupling electromagnetic signals between planar transmission lines and waveguides. A preferred exemplary structure comprises a shielded patch antenna and one or more capacitive diaphragms disposed adjacent to the patch antenna. This structure is advantageous to MMIC modules in connecting from a planar transmission line of a substrate carrying an MMIC to an external waveguide without the need of a non-planar back metal short, which is normally essential to avoid back scattering from the waveguide and also normally needed to achieve impedance matching. In structures according to the present invention, a patch antenna radiates into the waveguide while the antenna's ground plane reduces back scattering from the waveguide. The one or more capacitive diaphragms provide impedance matching between the microstrip and the waveguide.

Frequency voltage converter

Abstract: There is provided a frequency voltage converter comprises a first transmission line for transmitting an input signal and a second transmission line provided with a delay line circuit, a third transmission line for transmitting a reference signal and a fourth transmission line provided with a delay line circuit, a mixer circuit, and a locked loop having a control circuit for outputting the same control signal to control portions of both delay line circuits so that the amount of a delay by the delay line circuit reaches one cycle of the reference signal, thereby holding linearity with respect to the frequency of a modulated wave signal and executing frequency voltage conversion even when a center frequency is low.

A millimeter-wave radial line slot antenna fed by a rectangular waveguide through a ring slot

Abstract: A radial line slot antenna (RLSA) is a high gain and high efficiency planar antenna proposed for DBS subscribers in the 12 GHz band. In recent years, several radio systems have been developed in the millimeter wave band. In conventional RLS, a radial waveguide has been fed by a coaxial feeder. In the millimeter wave band, fabrication of the feeder is considerably difficult, since the physical size is small. High accuracy in manufacturing is needed to give high antenna efficiency. We have proposed a planar feed circuit with a ring slot and a microstrip line (see Kigure, Y. et al., IEICE Natl. Conv. Rec., B-1-102, 1999). The feed circuit may be easily integrated with an RF planar circuit. In this structure, however, undesired radiation to the back of the antenna is significant and the antenna efficiency is degraded. In terms of efficiency in the millimeter wave band, a rectangular waveguide is more attractive for feeding a radial waveguide. A rectangular-to-radial waveguide transformer through a ring slot is proposed. This transformer is slightly bulky, however there is no leakage. It is suitable for integrating with existing RF modules that have an interface to the rectangular waveguide. The rectangular-to-radial waveguide transformer through a ring slot is designed and fabricated at the 12 GHz band and we integrate a RLSA with this feed circuit at the 38 GHz band.

Single feed, multi-element antenna

Abstract: An array antenna (200) capable of use with a single signal feed has a transmission line oriented substantially parallel to a ground plane (220), which transmission line has a multiplicity of sequential sections with each sequential section having a different spacing from the ground plane (220) than each of its immediately adjacent sequential section. This stepped or varied impedance transmission line forms an array in which the sections spaced further from the ground plane (220) become active antenna elements. Controlling an electrical spacing between the ground plane (220) and transmission line provides relative phase control between the active elements and thereby phased-array directional control of the antenna.

Antenna apparatus and associated methods

Abstract: An antenna apparatus includes an antenna feed, a radio frequency (RF) receiver connected to the antenna feed, and a main reflector for reflecting received RF signal to the antenna feed along a received signal path for reflecting received RF signals from the main reflector to the antenna feed. Furthermore, received RF signals may be modulated by blocking the RF signals in the received signal path. A tracking controller is connected to the RF receiver for generating an antenna pointing control signal based upon modulated received Rf signals.