Showing papers on "Balun published in 1991"

Broadband monolithic passive baluns and monolithic double-balanced mixer

Abstract: The design and fabrication of four broadband monolithic passive baluns including CPW Marchand, multilayer MS Marchand, planar-transformer and broadside-coupled line baluns are presented. Operational frequencies range from 1.5 GHz to 24 GHz. Maximum relative bandwidths in excess of 3:1 are achieved. Simulated performances using full wave electromagnetic analysis are shown to agree with the measured results. Two accurate equivalent circuit models constructed from either electromagnetic simulated or measured S-parameters are developed for the MS Marchand and transformer baluns making the optimization of baluns and circuit design using the baluns much more efficient. The design of monolithic double-balanced diode mixer using two planar-transformer baluns is also presented. Without DC bias, the mixer shows a minimum conversion loss of 6 dB with the RF at 5 GHz and a LO drive of 15 dBm at 4 GHz. The measured input IP/sub 3/ of this mixer is better than 15 dBm over the 4 to 5.75 GHz frequency band. >

Quadrifilar helix antenna

Abstract: An improved helix antenna including a single unitary antenna having plural radiating elements extending radially from a common junction. A microstrip balun is connected to the plural antenna elements at the common junction. In a particular embodiment, the antenna includes four radiating elements arranged in a helical pattern and mounted such that a longitudinal axis extending through the axial center of the antenna is coincident with a longitudinal axis of the microstrip balun. One or more of the radiating elements includes a semi-circular loop to create phase relationships necessary for a circularly polarized beam pattern. The microstrip balun includes a transmission line and a ground plane on opposite sides of a dielectric substrate. The transmission line and the ground plane are tapered for impedance matching between the input and the output thereof.

Dielectric flare notch radiator with separate transmit and receive ports

Abstract: A dielectric antipodal flared notch radiator (50) with separate transmit and receive ports (72,76) for phased array and active array antennas. A circulator (80) is integrated directly to the broadside coupled-strip transmission line portions (78,88) of the antipodal flared notch radiator without the use of baluns. The look-in impedance of the radiator element is improved as a result of the circulator and lack of a balun. By sandwiching the antipodal flared notch between two additional layers of dielectric (54,56), the device can be made a building block for broadband active array antennas.

A 6 to 20 GHz planar balun using a Wilkinson divider and Lange couplers

Abstract: A simple broadband microstrip balun has been developed using a Wilkinson divider for power splitting followed by Lange couplers for phase shifting. This planar balun structure can be easily fabricated on an alumina substrate using a conventional MIC (microwave integrated circuit) process without the need for multilayer or suspended substrate techniques. The inherent wideband characteristics of the Wilkinson divider and Lange couplers and the symmetry of the structure have resulted in good broadband amplitude and phase balance performance. The balun fabricated on 10 mil alumina has an amplitude imbalance of +or-0.6 dB, average phase imbalance of 7 degrees , and a maximum total insertion loss of 1.2 dB from 6 to 20 GHz. >

Double-balanced high level wide band RF mixer

Abstract: A double-balanced wide band RF mixer includes a first bifilar balun transformer coupling a high level source of RF signal to the primary windings of a pair of trifilar balun transformers. The two output windings of each trifilar transformer are connected in series with the drain-source circuits of a pair of FET transistors which are alternately activated by a symmetric local oscillator signal. An IF signal with reduced second order products of the RF signal is developed between the output windings of the two trifilar balun transformers.

50 GHz sampler hybrid utilizing a small shockline and an internal SRD

Abstract: A 50 GHZ sampler whose performance is a result of the addition of a small GaAs nonlinear transmission line is described. The compact hybrid microcircuit also features a step recovery diode (SRD), a microstrip-to-slotline balun and a GaAs integrated sampling bridge to form a complete sampling subsystem. The conversion efficiency of the shockline-enhanced sampler was improved over the full measured frequency range of 2-60 GHz when compared to the response of the sampler that did not use a shockline. >

Multi-octave bandwidth balun

Abstract: A balun structure including a dielectric substrate having top and bottom surfaces on which are formed a splitter/combiner, a reference transmission line of length A and substantially constant characteristic impedance, and an inverting transmission line of length A and substantially constant characteristic impedance. The inverting transmission line in particular includes a first tapered planar section disposed on the top surface of the substrate and transitioning along its length from a narrow width to a wide width, and a second tapered planar section disposed on the bottom surface of the substrate and transitioning along its length from a wide width to a narrow width, such that the first and second tapered planar sections are rotated mirror images of each other.

K-band frequency up-converters using reduced-size couplers and dividers

Abstract: A reduced-size branch-line hybrid circuit and a rat-race circuit, both of which were designed on an uniplanar approach, are successfully applied to a small size K-band balanced up-converter and an image-rejection up-converter. These two circuits utilize a combination of high-impedance transmission lines and lumped-constant capacitors. The image-rejection up-converter also employs a lumped-element balun and a lumped-element Wilkinson combiner. The use of these four circuit greatly reduced the size of the up-converter chips. The fabricated up-converter showed good performance including conversion gain of 1.7 dB and image-rejection of more than 20 dB at the K-band. >

New uniplanar balun

Abstract: A new uniplanar CPW-slot double junction balun has been proposed. Being realised as a uniplanar equivalent of the microstrip-slot double junction transition, this balun is well suited for MMICs, and has better characteristics that other uniplanar baluns published up to now. The measured VSWR is less than 1.6 and insertion loss is about 0.7 dB for bandwidth ratio 1:6.< >

New broadband balun structures for monolithic microwave integrated circuits

Abstract: Two novel passive balun structures for use in MMICs (microwave monolithic integrated circuits) are described. They are especially relevant to wideband push-pull power amplifiers, being capable of handling several watts of power. They operate over bandwidths of up to 3:1 and can provide large impedance level transformations. Exact network synthesis procedures are used to generate prototypes and a three-dimensional field simulator is used to verify the corresponding physical circuits. A family of designs for 6-18 GHz and 6.15-13.5 GHz bands has been established. >

Balun transformer with common mode coil

Abstract: A balun transformer with a common mode coil is formed by parallel two-strand cable wound around a common core having through-holes through which the cable passes. The common mode coil can be connected either on the input side or the output side of the balun transformer. Because only one core is used to form both the balun transformer and the common mode coil, the outer dimensions of the transformer can be reached, along with manufacturing costs, to reduce the number of man-hours required to manufacture the transformer by this invention. This configuration also permits shorter connections between the balun transformer and the common mode coil.

Planar broadband MIC balanced frequency doublers

Abstract: Broadband microwave frequency doublers employing beam-lead Schottky barrier diodes in a novel planar balun configuration are presented. The doubler circuits can be scaled to different frequency bands. Two circuits have been developed with a nominal output power of +11 dBm covering the 6-18 GHz and 10-27 GHz bands, respectively. The output power level is sufficient to provide local oscillator power for unbiased single-balanced mixers. Excellent performance was achieved, combined with a wide operating bandwidth and flat frequency response. A minimal conversion loss of 8.4 dB and an output frequency ratio exceeding 1:3 were achieved. The high fundamental frequency isolation is of special note. A reverse operation mode is presented. It allows one to optimize the performance at low input power levels by forward-biasing the diodes. >

A Q-band monolithic balance resistive HEMT mixer using CPW/slotline balun

Abstract: A Q-band balanced, resistive high-electron-mobility-transistor (HEMT) mixer has been developed for integration in monolithic millimeter-wave receivers. The mixer consists of two AlGaAs/GaAs HEMTs, a coplanar-waveguide (CPW)-to-slotline local oscillator (LO) balun, and an active IF balun. CPWs are used to eliminate the backside or via-hole process step, which increases the circuit yield and shortens the processing time. The conversion loss of the mixer while downconverting a 42-46-GHz RF to a 2.3-3.2-GHz IF is between 4 and 8 dB using an LO drive of 14 dBm. A 17.5-dBm input two-tone third-order intermodulation intercept point is achieved with an LO drive of 10.5 dBm, while a 5.5-dBm input, 1-dB compression point can be achieved with an LO drive of 14 dBm. This is the first reported monolithic CPW resistive HEMT mixer operating at Q-band frequencies. >

Double balanced, coplanar, image rejection mixer uses monolithic MESFET quad

Abstract: A coplanar double balanced image rejection mixer with an input 1 dB compression level of +10 dBm is described which uses two MESFET ring quads with only +10 dBm LO (local oscillator) power. It is considerably more efficient in terms of LO power when compared to Schottky diodes. Eigen-circuits are used to model the balun performance. >

Multi-octave MMIC distributed mixers

Abstract: Four different MMIC distributed mixers are described and compared. The first is a mixer using a cascode of FETs, the second is a matrix distributed mixer, the third is a balanced mixer using common-source and common-gate FET pairs, and the fourth is a double-balanced mixer using an active RF/LO combiner and an active balun. >

A double balanced 6-18 GHz GaAs MMIC mixer

Abstract: A double balanced 6-18 GHz GaAs MMIC mixer was designed, fabricated, and tested. The mixer utilized two coupled-line baluns and four GaAs Schottky diodes. The mixer was fabricated on a 400- mu m GaAs substrate without backside processing or via-holes. It has a typical conversion loss of 7.5 dB over the RF and LO bandwidth of 6-18 GHz and a DC-1.5 GHz IF. Processing of the MMIC mixer is compatible with that of a MESFET based MMIC, such that integration of the diode based MMIC mixer with other functions on the same chip is possible. >

Image rejection frequency converter provided in planar technology

Abstract: There is described an image rejection frequency converter comprising essentially a balun (DIV) used as a power divider for coupling a local oscillator signal to the ends of two frequency mixers (MIX1, MIX2). Said mixers (MIX1, MIX2) have ports to which arrive or from which come out intermediate radiofrequency signals (Fig. 1). The invention consists principally of integration of the power divider (DIV) and the mixers (MIX1, MIX2) in a planar structure based on a new concept provided in microstrip and in coplanar line.

Bridge for measuring the reflection coefficient

Abstract: In a reflection-coefficient bridge, the voltage drop across a neutral arm of the bridge is supplied to the indicator via a coaxial cable. The center conductor of the coaxial cable is coupled to the one connecting point of the neutral arm of the bridge while the outer conductor thereof is coupled to the other connecting point thereof. The coaxial cable and a parallel-connected line portion constitute a balanced converter or balun. Both the coaxial cable and the line portion are wound onto at least one ferrite core. A d.c. voltage is fed to a test object, which is connected to the bridge by way of a coaxial line, through a compensating winding wound on at least one of said ferrite cores to the end of the line portion which is r.f. coupled to the frame.

Ground independent feed network for a multiterminal antenna

Abstract: A feed network for a multiterminal antenna which provides excitation to the antenna independent of ground. The feed network provides a voltage differential between terminals of the antenna instead of between a common ground point and a terminal so that the antenna achieves enhanced broadband performance via an attached balun for each coaxial cable. The feed network is comprised of a base, through which a plurality of coaxial connector extend, and a plurality of printed circuit boards positioned so as to define a centerline through the feed network. The printed circuit boards have a first side having a first, wide twin lead and a second side having a second, narrow twin lead such that the electrical signals conducted by the feed network are balanced between each pair of first and second twin leads. The twin leads of the printed circuit board are electrically connected to a corresponding connector of the plurality of coaxial connectors. The width of the etched twin lead decreases as it progresses along a linear converging path from the base towards the apex of the feed network at which point the trace of each twin lead is varied to follow a path parallel to a centerline of the feed network. Jumper wires are utilized to connect the twin leads at the apex of the feed network to the terminals of the antenna. The twin leads are spaced such that a single jumper wire may be connected to twin leads from two adjacent printed circuit boards.

Video doorphone equipment

Abstract: PURPOSE:To prevent a phenomenon inverting white and black from being generated by providing a baluns (balance/unbalance converters) in the transmission part of a host monitor equipment and the transmitting/receiving parts of a slave monitor equipment. CONSTITUTION:A video signal transmitted from a porch subordinate equipment 1 to a host indoor equipment 2 is transmitted to an additional monitor 4 by a transmitter 28. An amplifier 207 of this transmitter 28 amplifies an attenuated part in a two-line cable 3 between the porch subordinate equipment 1 and host indoor equipment 2. The signal amplified by this amplifier 207 is converted from an unbalanced state to a balanced state by a balun 309 and resistors 310 and 311, and transmitted to the additional monitor 4 while keeping balance. Then, the signal is converted from the balanced state to the unbalanced state by a balun 409 and resistors 410 and 411 in a receiver 29 of the additional monitor 4. Further, common mode noise induced by the two-line cable 3 between the host inddor equipment 2 and additional monitor 4 is removed by this balun 409. The video signal converted to the unbalanced state by the receiver 29 is transmitted to the additional monitor in the next step by a transmitter 30 and samely, the video signal is transmitted to the additional monitor in the final step.

Wideband Balanced Frequency Doublers - A Proposed Novel Planar MIC Structure

Abstract: Wideband microwave frequency doublers employing beam-lead Schottky barrier diodes in a new planar balun configuration are presented. Measurement results for output frequencies up to the K-band show good agreement with simulated results. A conversion loss less than 8.5 dB and an output frequency ratio exceeding 1 : 3 were achieved. Further a novel facility to combine the doubler with a pin-diode series switch is proposed. The low-cost, small-sized multipliers can be integrated into complex hybrid systems, e.g. to provide selectable local oscillator sources for a fundamental mixer in broadband measurment instrumentation.

High frequency, wide band, triple balanced mixer

Abstract: A triple balanced mixer includes two miniature diode quad rings (12, 14) positioned on opposite faces of a duroid sheet (16) which is integral with a duroid layer (18) of one of three pairs of parallel baluns (28, 30, 32). An LO balun pair (30) is connected directly to the ring terminals (80, 82, 84, 86) while ribbon connectors (34, 36) are used to interconnect the other balun pairs (28, 32) to the ring terminals (80, 82, 84, 86, 88, 90, 92, 94). The baluns (28, 30, 32) are orthogonally disposed and have a particular curved shape in order to accomodate the miniature rings (12, 14). The rings (12, 14) are suspended from the baluns (28, 30, 32) and positioned within a cavity (38) of a housing (20) which is provided with electromagnetic energy absorbent material and which is selectively dimensioned to minimize signal loss from the pairs of baluns (28, 30, 32), balun connectors (34, 36) and rings (12, 14).

Analysis and design of a planar balun

Abstract: The analysis and design of a planar balun is presented. The balun consists of three closely placed parallel metallic strips situated on a dielectric substrate. The effective dielectric constants and characteristic impedances for the three independent propagating modes supported by the structure are obtained using the spectral domain approach. Design information is extracted from a three-port admittance matrix derived in terms of these modes.

Duplex sperrtopf balun

Abstract: PURPOSE:To form a wideband balun capable of covering an L1 band sufficiently by providing two cylindrical conductors with different length in coaxial fashion at the top part of a Sperrtopf balun. CONSTITUTION:The length of a first cylindrical conductor 10 is set differently from that of a second cylindrical conductor 20, and the length of the first cylindrical conductor 10 is 1/4 the wavelength lambda1 of a reception signal, and that of the second cylindrical conductor 20 is 1/4 the wavelength lambda2 of the reception signal. In such a case, since the input impedance of the first cylindrical conductor 10 is infinite to a signal with frequency of wavelength lambda1, no leakage current flows, and an equivalent circuit becomes the one in which an equilibrium line 40 is directly connected to a coaxial cable 30. The same equivalent circuit can be obtained in the second cylindrical conductor 20. Therefore, the equivalent circuit in which the equilibrium line 40 is almost connected directly to the coaxial cable 30 can be obtained in areas with two frequencies.

High-density circuit approach for low-cost MMIC circuits

Abstract: Using spectral domain coupled transmission line calculations and computer programs to generate circuit files for standard circuit analysis programs, a double balanced monolithic mixer with RF/IF overlap has been developed using spiral baluns. This technique can be employed to extend the design of high density MMIC circuits to frequencies greater than 20 GHz.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A New Uniplanar Double Balanced Mixer with High Port to Port Isolation

Abstract: A design of new uniplanar double balanced mixer with a high port to port isolation is presented. Through the use of novel CPW-slot double junction balun, the need for via holes and back metalization has been eliminated. Hence, this mixer can be easily adapted to monolithic integrated circuits. The mixer realized has superior characteristics in comparison to other uniplanar mixers published up to now. An operating bandwidth, characterized by more than 1:6 frequency ratio has been achieved, at up to 10 GHz, with a conversion loss of 6.0 to 8.5 dB and LO/RF isolation greater then 30 dB.

High-dynamic-range mixer using novel balun structure

Abstract: A wide band 6 to 18 GHz mixer has been designed and developed for high dynamic range operation. The mixer utilizes monolithic MESFET quad as a mixing element for the double balanced mixer circuit. The baluns have been developed on low dielectric constantsubstrates and are fully compatible for a planar approach. The mixer circuit exhibits anIF bandwidth of 2 GHz to 6 GHz and has a measured input intercept point of +25 dBm. Thefabricated RF and LO baluns have demonstrated an excellent performance in amplitudeand phase up to 21 GHZ. The IF baluns demonstrate similar performance from 1 GHz to1 0 GHz. The design is transferable to milli-meter range. A 0.5 micron gate length MMIC process was used to fabricate the matched quad. GaAs FET's with double recessed channels, for high breakdown and low parasitic resistance, were used.INTRODUCTION The objective of the project was to design and develop a wide-band and high dynamic range mixer for EW receiver and radar applications. The tasks included the

Harmonic wave generating circuit supplying harmonic wave directly to slot line

Abstract: PURPOSE:To minimize the harmonic loss without use of a balun by providing an output terminal to both ends of a slot line. CONSTITUTION:When a fundamental wave input 10 is inputted from a coaxial cable 16 to a conductor section 12c, the conductor section 12c and a conductor section 12a are separated and the fundamental wave input 10 is inputted to a harmonic wave generator 18 only. Then the harmonic wave generator 18 generates a harmonic wave and supplies it to output terminals OUT1, OUT2 of a slot line 13. An inductor 17 is a high impedance to a high frequency output and no signal is outputted to an input terminal of the coaxial cable 16.

Technical memorandum: matrix analysis of split coaxial balun

Abstract: A convenient method of analysing the operation of a split coaxial balun is presented. The analysis provides a complete description of the baluns' impedance transforming properties as a function of frequency.