Showing papers on "Balun published in 1993"

A broadband, planar, doubly balanced monolithic Ka-band diode mixer

Abstract: A planar monolithic diode mixer that achieves 5-10-dB conversion loss and very low distortion and spurious responses over a 26-40-GHz RF and local oscillator (LO) bandwidth and DC-12-GHz IF is described. Two types of diodes have been used: the first used the gate-to-channel junctions of 0.2- mu m*80- mu m InGaAs HEMTs; and the second used Schottky diodes realized in HBT technology. The baluns are Marchand-like coplanar structures. >

High power solid state r.f. amplifier

Abstract: Although known because of the high packaging inductances and thought to be wholly unsuitable for RF amplifiers, high voltage power switching MOSFETs (11, 12, 41, 42) of the type having coplanar leads having inductances on the order of between 8nH and 15nH are used in an RF amplifier. The individual devices (11, 12, 41, 42) operate on a high impedance load line to render the high inductance of the coplanar leads insignificant. The circuit configuration presents a high impedance to the output (14) via balun (20), eliminating the need for expensive combiners and low inductance packaging.

Wideband (DC to GHz) balun

Abstract: An ultra wide band DC to GHz balun consisting of transmission lines, a small inverting junction, and an RC network connecting the shields of the balanced load transmission lines such that an unbalanced source sees a matched load from DC to GHz.

Design and performance of a planar star mixer

Abstract: This paper describes the realization of a hybrid star mixer as a planar circuit. The mixer has a minimum conversion loss of 5 dB and, for a conversion loss of less than 9 dB, spans over 2.2 GHz in IF bandwidth and 8 GHz in RF/LO bandwidth. The mixer employs a novel, planar balun structure, similar to conductor-backed CPW, that is suitable for realization as a monolithic circuit. >

A broadband, planar, doubly balanced monolithic Ka-band diode mixer

Abstract: A planar monolithic diode mixer that achieves 5-10-dB conversion loss and very low distortion and spurious responses over a 26-40-GHz RF and local oscillator (LO) bandwidth and DC-10-GHz IF is described The diodes are the gate-to-channel junctions of 02- mu m*80- mu m InGaAs HEMTs, and the baluns are Marchand-like coplanar structures >

Monolithic double balanced microstrip mixer with flat conversion loss

Abstract: A double balanced microstrip mixer circuit for a monolithic microwave integrated circuit comprising a diode ring modulator coupled to a first balun for supplying radio frequency signals to the mixer circuit and a second balun for supplying a signal generated locally to the mixer circuit, two outputs leading from the diode ring modulator for providing an intermediate frequency signal, a first pair of circuits coupled between the first balun and the diode ring modulator and a second pair of circuits coupled between the second balun and the diode ring modulator, for enabling broadband frequencies to be applied to the diode ring modulator independent of impedances created by the first and second baluns. The circuit further includes two low pass filters each coupled to one of the two outputs for rejecting unwanted feed through and a in-phase combiner coupled to the low pass filters.

FET mixer having transmission line transformer

Abstract: A mixer comprising four FET transistors in a MMIC, a reflection transformer having tri-filar windings, an IF balun, an RF balun, a local oscillator balun, a pair of load resistors, a pair of series resistors, and a pair of series capacitors. The mixer is packaged in a lidded header similar to a large TO-8 metal package.

Dipole antenna having co-axial radiators and feed

Abstract: A dipole antenna comprises first and second antenna radiators and first and second balanced transmission-line conductors which are electrically connected to the first and second antenna radiators, respectively. An inner conductor and a shield of a coaxial cable are electrically connected to the first and second balanced conductors, respectively to transmit a drive signal to the first and second antenna radiators. A balun is electrically connected to an intersection of the coaxial cable and the first and second balanced conductors. The first and second antenna radiators and the first and second balanced conductors are supported substantially along a common axis such that the first and second balanced conductors separate the first and second antenna radiators from the balun and coaxial cable. The balun can also be supported generally along the same axis.

Biased FET mixer

Abstract: A mixer including a "reflection" transmission line transformer having at least first and second ports. The ports are connected such that nearly complete coupling of energy between the ports relies on substantially complete reflection of energy at a reference plane of the transformer. In a preferred implementation there is produced at the first port an intermediate frequency (IF) signal and received a DC bias signal via an IF balun. At the second port there is inputted a radio frequency (RF) signal through an RF balun. The DC bias signal will preferably be provided to a set of phase-selecting GaAs MESFET transistors operatively connected between an LO balun and a third port of the reflection transformer. In the preferred implementation the MESFET transistors are realized using an MMIC.

Novel miniaturised wideband baluns for MIC and MMIC applications

Abstract: Very compact novel planar broadband baluns are described. Each balun consists of two Lange couplers. Less than 0.3 dB and 2.5 deg for the amplitude and phase balances, respectively, have been measured over the 1.0-2.2 GHz bandwidth for a microstrip balun. As compared with other reported baluns, these baluns are simpler, more compact, easier to design, and fabricated on only one side of the substrate. They are thus very attractive for microwave integrated and monolithic integrated circuit applications.

A planar quasi-optical SIS receiver

Abstract: A planar, quasi-optical SIS (superconductor-insulator-superconductor) receiver operating at 230 GHz is described. The receiver consists of a 2*5 array of half-wave dipole antennas with niobium-aluminum oxide-niobium SIS junctions on a quartz dielectric-filled parabola. The 1.4-GHz intermediate frequency is coupled from the mixer via coplanar strip transmission lines and 4:1 balun transformers. The receiver is operated at 4.2 K in a liquid helium immersion cryostat. Accurate measurements of the performance of single untuned array receiver elements are reported. A mixer noise temperature of 89 K DSB (double sideband), receiver noise temperature of 156 K DSB and conversion loss of 8 dB into a matched load have been obtained. This mixer noise temperature is approximately a factor of two larger than that of current state of the art waveguide mixers using untuned single junctions a the same frequency. >

Active power line conditioner having capability for rejection of common-mode disturbances

Abstract: The present invention provides an APLC which has improved common-mode disturbance rejection capability when compared with similarly-sized devices constructed according to current teachings. The need for an isolation transformer is, in many cases, eliminated by the invention. The invention alters the coupling transformer of the series parallel APLC or the isolation inductor of the newly-proposed inductor-parallel APLC to create a balun effect in the high and low conductors of the electrical supply network. Particularly, first and second windings are substituted for the single winding of the transformer primary or the isolation inductor. These two windings are serially-connected on the high and low conductors, respectively, with appropriate polarity such that self-inductance values of each are additive. Low pass capacitors and surge protectors may also be added to further protect the APLC and the load.

CAD procedures for planar re-entrant type couplers and three-line baluns

Abstract: A generalized network model for coupled multiconductor transmission lines is derived based on normal mode parameters. The model is used in the design of planar re-entrant type couplers. By using this network model, the design of a planar re-entrant coupler can be derived from the design of a traditional two-line coupler. The design procedure for single-layer planar baluns using three-conductor transmission lines has also been developed based on this network model. Design procedures and examples are presented. >

A monolithic multifunction EW broadband receiver converter

Abstract: A unique multifunction receiver converter chip, consisting of RF amplifiers, switches, a lumped-element filter, and a double-balanced mixer, has been developed The chip design employs various circuit design refinements, such as amplifier feedback techniques to enhance stability and repeatability, FET switches to reduce power consumption, and a lumped-element filter to reduce size The double-balanced mixer topology eliminates IF extraction problems and combines the best performance characteristics of active and passive baluns while employing diode mixing elements >

Diode mixer implemented in a planar monolithic IC

Abstract: A monolithic diode star mixer incorporating an RF balun and a local oscillator balun in which a center microstrip conductor for each of the baluns is configured between parallel strip transmission lines in a common plane. The RF and local oscillator baluns are positioned in a ground plane such that the baluns are at relative right angles to each other and in which the center microstrips are connected. A center ring conductor enables the diodes associated with the mixer to be connected to the transmission lines and a common connection point. Additionally, an intermediate frequency transmission line is also connected to the conductive ring.

Investigation of photoconductive silicon as a reconfigurable antenna

Abstract: A reconfigurable antenna whose size, shape, and polarization can be dynamically modified is a desirable component for today's communication and surveillance systems. To date most proposed reconfigurable antenna concepts have used a matrix of conducting elements connected by electronic/optoelectronic switches with the on-off pattern of the switches defining the size or shape of the antenna. An alternative approach for realizing this concept is to exploit the photoconductive effect in various semiconductor materials. This paper reviews the general theory of photoconductivity in semiconductors emphasizing the parameters relevant to this application. The experimental arrangement and the initial results for our proof- of-concept demonstration are then presented. In this experiment a bow-tie shaped transient carrier distribution was created in a 4 inch diameter, high resistivity (6 - 8 k(Omega) -cm) Si wafer through illumination with a pulsed Nd:Glass laser. The voltage amplitudes measured by the transient Si bow-ties (three different wafers) were 45 - 50% of those received in the same environment by an equivalent copper bow-tie antenna designed to operate from 1.4 - 2.1 GHz. Analysis of this initial data indicates that an optimized design incorporating improved semiconductor processing techniques, an optimized feed/balun, soldered interconnects, and impedance matching would significantly improve performance.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Computer-aided design of microwave frequency doublers using a new circuit structure

Abstract: A circuit structure for microwave frequency doublers is presented. It has been used in the design of a MMIC (monolithic microwave integrated circuit) doubler. Its major advantages are effective suppression of the unwanted odd-order harmonics and conversion gain to the desired second harmonic. These advantages have been demonstrated by computer simulation and further verified by measured results for the MMIC circuit. The circuit can be used in both balanced and unbalanced output configurations, without requiring baluns or transformers. The fundamental frequency suppression was found to be over 50 dB, while better than 3 dB conversion gain was achieved. >

A low-profile, broadband balun feed

Abstract: A low-profile balun approach is described which is a modified version of the proven exponential tapered balun, capturing its inherent broadband, low-cost characteristics in a compact package. This approach provides a broadband antenna with coaxial connectors suitable for low-profile skin mounting. It may also be used with conventional cavity-backed antennas. Implementation methods apply to single- and dual-polarized apertures. Hardware design configurations and preliminary test data voltage standing wave ratios are given. >

Signal transmitting device

Abstract: PURPOSE:To suppress the gain variance and to stabilize the transmission of signals by supplying evenly the transmission signals to plural points of a transmission element via the baluns and then also transmitting evenly the transmission signals from those points of the transmission element via the baluns. CONSTITUTION:Each of baluns 151-153 of a transmission element 101 divides an input check signal Si into two pieces as four signals and then converts the impedance into 50OMEGA, 1kOMEGA and then 50OMEGA again to supply these converted signals to the feeding points A1-A4 of a base board 101b. The elements provided on a base board 112b of a reception element 112 receive the signals radiated from the points A1-A4 by the capacity coupling and outputs these signals through the reception points B1-B4. Each of baluns 154-156 connects together two signals at 2 stages and converts the impedance into 50OMEGA, 1kOMEGA and 50OMEGA again to output a reception signal So. Therefore an averaged distribution is secured for the transmission intensity of signals between the elements. Then the gain variance and the signal deterioration can be suppressed in a transmission signal band. Thus the transmission of signals can be stabilized.

Connection device between an antenna and a microelectronic enclosure

Abstract: An electronic device includes an antenna enclosure provided with a circuit on which an antenna is etched and a balun circuit for feeding the antenna, itself connected to a microelectronic enclosure fitted with an airtight connection having a sealed glass bead with at least one conducting wire passing through it. The balun circuit has at least two different tracks on each side of a dielectric substrate. At least one immediate electrical contact is provided between the conducting wire of the enclosure and one of the tracks of the balun circuit, at the same time as a direct mechanical fixing of the antenna enclosure to the microelectronic enclosure, accompanied by another connection of the same type or an earth transfer conductor which is connected to the other balun track and is in contact with the microelectronic enclosure.

Application of bilateral slotlines to broadband microwave components

Abstract: Novel design of doubly-balanced mixers/modulators and even order frequency multipliers employing broadband microstrip-balanced stripline-bilateral slotline-unilateral slotline-microstrip baluns is proposed. Circuit concept is presented first, followed with the design and evaluation of balun components which involved a transverse resonance approach to the analysis of asymmetrical bilateral slotlines. Examples of application are: an X-Ku band mixer, a Ku-K band frequency doubler and a low conversion loss varistor frequency quadrupler circuit whose parameters have been evaluated numerically.

Surface mounting balun

Abstract: PURPOSE:To realize easy mounting onto a printed circuit board of a balun for surface mounting to be used for a distributing circuit and mixing circuit or the like of a high frequency RF unit. CONSTITUTION:End portions of lead wires 18 to 21 are led out to the outside of a through hole 15 and a film is removed to form terminals 7a to 11a. The terminals 7a to 11a are beng along a lead position indication mark 22 or lead positioning groove formed at the external wall surface of a core 14 and can be surface mounted on a land of the printed circuit board. With such structure, since connection can be realized through direct abutment on the land of the printed circuit board, automatic mounting can be done easily at a low cost.

Phase feeding type antenna system

Abstract: PURPOSE:To adjust an antenna element phase characteristic of the phase feeding antenna system with a phase adjustment device. CONSTITUTION:A balanced cable 1, a balun 3, a distributer 8, an antenna coupler 5 and a transmitter-receiver 6 are sequentially connected to one A of two sets of antenna element groups A, B and a balanced cable 2 prolonged from the other antenna element group B is connected to the distributer 8 via a balun 4 and a phase adjustment device 7. Thus, each antenna element is set to be inductive or capacitive by a phase adjustment device near the transmitter- receiver.

Resonant balun with arbitrary impedance

Abstract: A balun circuit comprising a first signal source connected across a first inductive means and connected to the latter a first capacitive means. To that network are connected a second signal source, a second inductive means, and a load to be matched to the signal sources. With the right choice of component values to produce a resonant condition, a balun that interfaces two balanced signal sources to an unbalanced single-ended load results capable of low insertion loss, arbitrary impedance transformation ratio, testability in the form of a 50 ohm port for in-circuit power monitoring and circuit characterization, class E operation, and easy implementation, as only standard L and C components are necessary. The circuit is reversible for connecting a single source to a balanced load.

Signal transmission system

Abstract: (57) [Summary] [Object] To provide a signal transmission system that can perform CATV transmission using a balanced pair type cable, and that does not cause a ghost without leakage of radio waves from the balanced pair type cable. [Configuration] A shielded balanced pair type cable 2 for an integrated wiring system is connected via a shielded balun 3 in the middle of a CATV system coaxial cable 1, and the balanced paired type cable 2 and the balun 3 are shielded. Made into a structure. The balanced pair type cable 2 and the balun 3 are grounded with a resistor having a high resistance value exceeding the characteristic impedance of the coaxial cable 1.

A monolithic multifunction ew broadband receiver converter

Abstract: A unique multifunction receiver converter chip, consisting of RF amplifiers, switches, a lumped-element filter, and a double-balanced mixer has been developed. The chip design employs various circuit design refinements, such as amplifier feedback techniques to enhance stability and repeatability, FET switches to reduce power consumption, and a lumped-element filter to reduce size. The double-balanced mixer topology eliminates IF extraction problems and combines the best performance characteristics of active and passive baluns while employing diode mixing elements.

A new circuit structure for microwave frequency doublers

Abstract: A novel circuit structure for microwave frequency doublers is presented. It has been used in the design of a MMIC (monolithic microwave integrated circuit) doubler. Its major advantages are effective suppression of the unwanted odd-order harmonics and conversion gain to the desired second harmonic. These advantages have been demonstrated by computer simulation and further verified by measured results for the MMIC circuit. The circuit can be used in both balanced and unbalanced output configurations, without requiring baluns or transformers. The fundamental frequency suppression was found to be over 50 dB, while better than 3 dB conversion gain was achieved. >

A non-magnetic low-loss wideband quadrature hybrid for front-end applications in magnetic resonance systems

Abstract: The quadrature hybrid described below was developed for circular polarizing antennas in magnetic resonance systems. It is based on a 180°/3dB wideband hybrid cascaded with a 90° two-phase network. Due to this combination a quadrature hybrid (90°/3dB) with very little phase and amplitude imbalance (<±1° and <±2.5%, respectively) over a bandwidth of more than two octaves is achieved. Except one semi rigid cable balun, all transformers and inductors are realized on a double layer low-loss PTFE-board in symmetric strip line technique. The hybrid is thus easy to fabricate with high reproducible data. Since ferrite material is strictly avoided 15 kW peak power in close proximity to the strong main field magnet can be handled. Insertion losses in the receiving paths are about 0.15 dB to maintain the original signal to noise ratio of the antenna.