Abstract: A directional bridge for measuring propagated signals to and from a source device to a load device where both the source device and load device are in signal communication with the directional bridge is disclosed. The directional bridge may include a first bridge circuit network and a first sensing element in signal communication with the first bridge circuit network. The first sensing element may produce a first measured signal that is proportional to the propagated signals.

Abstract: A microwave directional coupler includes a microstrip conductor formed on a dielectric substrate and forming a main transmission line having in and out ports that receive signals to be coupled. A substantially U-shaped microstrip conductor is formed over the dielectric substrate adjacent to the main transmission line and forms a secondary transmission line having a coupling section and coupler port. A load resistor is formed within the secondary transmission line, and the coupling section is less than a quarter wavelength of a center frequency.

Abstract: Couplers are disclosed that include first and second mutually coupled conductors. The coupled conductors may be regular or irregular in configuration, and for example, may be linear, including rectilinear or with one or more curves, bends or turns, such as forming a ring, coil, spiral or other loop. One or more sections of a coupler may be on different levels and separated by a dielectric medium, such as air or a dielectric substrate. Coupled conductors may be facing each other on the same or spaced-apart dielectric surfaces, such as opposing surfaces of a common substrate, and each conductor may include one or more portions on each side or surface of a substrate. In some examples, a coupler may include plural coupled sections, with conductors in one section being only broadside coupled, and conductors in another section being edge-coupled.

Abstract: The length of a transmission line delay circuit is halved by inserting a directional coupler in the signal path ahead of the transmission line and either open circuiting or short circuiting the other end of the transmission line. The signal traveling through the directional coupler and through the transmission line is reflected back at the end of the transmission line, and the reflected signal is carried to the coupled output of the directional coupler. Since the signal travels through the transmission line twice, the delay time is doubled. Therefore, for a given delay requirement, the length of transmission line required is only half of the length required for prior art transmission delay lines.

Abstract: A coupler (10) having a first line (1) and a second line (2) also comprises a resonant structure (3) including a capacitor (5) and an inductor (4). The coupler (10) thus delivers a coupling signal S31 that is substantially frequency independent over a frequency domain above the resonance frequency of the resonant structure (3). Also, the signal S31 has a high degree of directivity. The coupler (10) can be provided as part of an integrated electronic component, such as a multilayer substrate, a thin-film module or an IC. It can be applied in an electronic device (100) between a power amplifier (101) and an antenna (103). The coupling signal S31 will thus be provided to a controlling circuit (102).

Abstract: A coupler is disclosed that includes first and second mutually coupled spirals or loops disposed on opposite sides of a dielectric substrate. The substrate may be formed of one or more layers and the loops may have a number of turns appropriate for a given application. Conductors forming the loops may be opposite each other on the substrate and each loop may include one or more portions on each side of the substrate. Each conductor of the coupler may include an intermediate portion having a width that is more than the width of end portions. An extension may extend from each respective intermediate portion, with the two extensions extending in non-overlapping relationship. In some coupler sections, an extension may be peninsular.

Abstract: A symmetrical or asymmetrical coupler includes first and second conductive lines formed as at least first and second coupled sections and a delay section between the first and second coupled sections. The coupler may include plural alternating delay sections and coupled sections. Delay sections may include delay loops formed in both lines. One line may be a mirror image of the other line.

Abstract: A directional bridge coupler includes a coaxial balun having a coaxial cable with a plurality of ferrite beads disposed about an outer conductor of the coaxial cable, and a circuit substrate accommodating a directional bridge coupled to an output of the coaxial bridge. A conductive package having an internal cavity houses the circuit substrate and the coaxial balun. A polyiron saddle straddles a portion of the coaxial balun within the internal cavity of the conductive package.

Abstract: A circuit assembly may include one or more coupler sections, and may include a phase inverter and/or a phase shifter. A coupler section may include a phase inverter. A coupler may include first and second mutually coupled spirals disposed on opposite sides of a dielectric substrate. Conductors forming the spirals may be opposite each other on the substrate and each spiral may include one or more portions on each side of the substrate. Some circuit assemblies may include first and second multi-port coupler sections. A phase inverter or a phase shifter may be coupled between coupler sections. In some examples, a circuit assembly may include first and second conductors each having first and second ends and mutually inductively coupled turns, and a capacitive device coupling the first ends of the first and second conductors to a reference potential.

Abstract: The present invention proposes a coupling device, comprising a substrate (1), a conductive layer (2) covering a first surface of said substrate (1), at least two electromagnetically coupled lines (3a, 3b) being provided opposite to said first surface and at least one thereof being covered by at least one cover layer (4, 5) wherein at least one capacitor (C1, C2, C3, C4) is connected between a first end of at least one of said at least two lines (3a, 3b) and said conductive layer (2). The at least one capacitor is a buried capacitor grounded in order to equalize unequal phase velocities otherwise degrading the performance of e.g. broadside coupled structures in an inhomogeneous substrate structure such as for example microstrips in a multilayer LTCC. Therefore the present invention enables coupling devices having a high performance and offering in that way the best of all possible design scenarios in terms of wideband performance, size and cost.

Abstract: A semiconductor device with integrated circuits includes superimposed layers provided at different levels on a substrate, and including a metal strip (3) formed in a reference layer and through which an electric current passes, a metal ground plane (4) formed in a layer situated at a level lower than the reference layer and having a slit (5) which lies below the strip while running alongside it, an electrostatic shield (6) formed in a layer located at a level lower than the ground plane and comprising a multiplicity of spaced out bands (7), made of an electrically-conducting material, that extends across the slit, and conducting junctions (4a, 4b) making it possible to electrically connect the ends of each band to the parts of the ground plane situated on either side of its slit.

Abstract: A directional coupler comprises, arranged on a substrate, two first ports connected by a first line and two second ports connected by a second line. The lines extend through a coupling zone in which they are separated by a conductor area not connected to the lines.

Abstract: A coupler is disclosed that includes first and second mutually coupled spirals disposed On opposite sides of a dielectric substrate. The substrate may be formed of one or more layers and the coils may have a number of turns appropriate for a given application. Conductors forming the spirals may be opposite each other on the substrate and each spiral may include one or more portions on each side of the substrate. Each conductor of the coupler may include an intermediate portion having a width that is more than the width of end portions. An extension may extend from each respective intermediate portion, with the two extensions extending in non-overlapping relationship.

Abstract: A power splitter that has a small package size and repeatable electrical characteristics. The power splitter includes a low temperature co-fired ceramic (LTCC) substrate with several layers. Electrical components such as resistors and capacitors are integrated within the LTCC substrate. A transformer is attached to the upper surface of the LTCC substrate and is electrically connected to the resistors and capacitors. The transformer provides impedance matching and dividing functions. The LTCC substrate has electrically conductive vias extending therethrough. The vias are used to connect the power splitter to an external printed circuit board. The vias are also used to make electrical connections between the layers of the LTCC substrate.

Abstract: A microstrip coupler is provided which includes an controlled capacitance bridge for improved directivity as compared to prior art controlled capacitance bridges. The novel controlled capacitance bridge provides the functionality of prior art wire or ribbon controlled capacitance bridges and also provides the necessary capacitance to compensate for the different phase velocities of odd and even modes in the transmission lines. Both the dimensions of the controlled capacitance bridge and the dimensions of an input microstrip conductor may be adjusted to provide the appropriate level of capacitance. In some embodiments, the controlled capacitance bridge connects segments of an input microstrip conductor. In other embodiments, the controlled capacitance bridge connects microstrip conductors which are configured to couple an input signal from an input microstrip conductor.

Abstract: The present invention provides a ninety degree coupler for a frequency range of 100 mHz to gigaHertz ranges and including a minimum number of components employing a four port device which receives an input signal and splits it between a transformer coil and another reactor and couples it to another port and splits it between the transformer and a capacitor, then cross-connecting to a capacitor where phase shift is created by the inductors and capacitors resulting in phase shift between the signal ports remaining at 90 degrees over a wide frequency band.

Abstract: A microwave directional coupler includes a first transmission line having an input port and an output port, and a second transmission line having a coupled port and a terminated port. The second transmission line is electromagnetically coupled to the first transmission line. A first capacitor is coupled between the input port and a reference potential, such as ground, a second capacitor is coupled between the output port and the reference potential, a third capacitor is coupled between the coupled port and the reference potential, a fourth capacitor is coupled between the terminated port and the reference potential, and a fifth capacitor is coupled between the output port and the terminated port. The microwave directional coupler has a small size in comparison with prior art directional couplers.

Abstract: A microstrip coupler is provided which includes an controlled capacitance bridge for improved directivity as compared to prior art controlled capacitance bridges. The novel controlled capacitance bridge provides the functionality of prior art wire or ribbon controlled capacitance bridges and also provides the necessary capacitance to compensate for the different phase velocities of odd and even modes in the transmission lines. Both the dimensions of the controlled capacitance bridge and the dimensions of an input microstrip conductor may be adjusted to provide the appropriate level of capacitance. In some embodiments, the controlled capacitance bridge connects segments of an input microstrip conductor. In other embodiments, the controlled capacitance bridge connects microstrip conductors which are configured to couple an input signal from an input microstrip conductor.

Abstract: A directional coupler that has a small package size and repeatable electrical characteristics. The directional coupler includes a low temperature co-fired ceramic (LTCC) substrate with several layers. Electrical components such as resistors and capacitors are integrated within the LTCC substrate. A transformer is attached to the upper surface of the LTCC substrate and is electrically connected to the resistors and capacitors. The LTCC substrate has electrically conductive vias extending therethrough. The vias are used to make electrical connections between the layers of the LTCC substrate.

Abstract: The present invention discloses a miniature high directivity multi-band coupled-line coupler for RF power amplifier module application. The coupler utilizes a three-coupled-line structure, with a first RF line designated coupled line for the GSM 900 MHZ band, a second RF line designated coupled line for the DCS/PCS 1800/1900 MHZ band, and a common coupled line. A first capacitor is connected between the center of the first line and the center of the common line and a second capacitor is connected between the center of the second line and the center of the common line. The coupler has a length considerably less than the length of a quarter wave length coupler while achieving directivity requirements for both GSM band and DCS/PCS band.

Abstract: A lumped element ring balun (60) including elements patterned on a monolithic substrate (62) in a compact design. The balun (60) includes four inductors (64, 66, 68, 70) and a plurality of capacitors (190, 192, 198, 202, 214, 226) electrically coupled together to provide RF output signals that are 180° out of phase with each other. The inductors (64-70) are symmetrically disposed in a rectangular area on the substrate (62). A first pair of the inductors (64, 66) is positioned at one end of the rectangular area, and a second pair of the inductors (68, 70) is positioned at opposite end of the rectangular area. All of the capacitors are formed on the substrate (62) in a central circuit area (72) between the first pair of inductors (64, 66) and the second pair of inductors (68, 70). Inner ends (76, 92, 98, 106) are coupled to circuit elements in the circuit area (72) by a metallized trace (120, 136, 150, 170) extending through an air bridge (124, 140, 154, 174).

Abstract: A layered directional coupler including conductive traces placed along predetermined axes for making contact with main and auxiliary signal lines. The axes are positioned at predetermined angles relative to each other to maximize the area for making contact thereto, which minimizes the size of the directional coupler. Ground planes are used to minimize parasitic coupling between the traces. The main and auxiliary signal lines are provided by inductively coupled juxtapositioned spiral coils which coupling maximize the characteristics of the coupler.

Abstract: A layered directional coupler including conductive traces placed along predetermined axes for making contact with main and auxiliary signal lines. The axes are positioned at predetermined angles relative to each other to maximize the area for making contact thereto, which minimizes the size of the directional coupler. Ground planes are used to minimize parasitic coupling between the traces. The main and auxiliary signal lines are provided by inductively coupled juxtapositioned spiral coils which coupling maximize the characteristics of the coupler.

Abstract: Process aimed at the extraction of electrical signals emanating from the two ends of a two wire link between two installations exchanging data, wherein a probe comprising an attenuation cell is plugged in on either side of a break point situated on the line pair, then the connections thus established are isolated in such a way as to transfer the signals to the attenuation cell, the attenuation cell is activated by progressive withdrawal of active components, high-impedance signals are tapped off at the two ends of the attenuation cell, and signals which are images of the electrical signals dispatched by one or other of the ends of the line pair are obtained as output from the attenuation cell, after analogue calculation based on subtraction of the signals and multiplication by a constant which is directly related to the value of the attenuation of the cell.

Abstract: An RF wideband amplifier system is provided that includes an M way splitter for receiving an RF input signal and splitting same into M RF signals for respective application to M power amplifier modules PAM-1 to PAM-M that amplify the M signals and apply the amplified M signals to an M way combiner that applies an amplified RF signal to a load. A main controller provides an automatic level control reference signal, representative of the desired output power level of each of the power amplifier modules.

Abstract: Disclosed herein is a multi-layer chip directional coupler. The multi-layer chip directional coupler has a first ground pattern, a coupling signal line, a main signal line, a second ground pattern, and a plurality of ports. The first ground pattern is formed on the upper surface of a first dielectric layer. The coupling signal line is formed of a conduction pattern on the upper surface of a second dielectric layer. The main signal line is formed of a conduction pattern on the upper surface of a third dielectric layer formed over the second dielectric layer. The second ground pattern formed on the upper surface of a fourth dielectric layer formed over the third dielectric layer. A plurality of ports is formed on the side surfaces of the first to fourth dielectric layers.

Abstract: Apparatus for monitoring a signal at an intermediate point on a series impedance source terminated unidirectional transmission line employs a voltage probe, a current probe, and a summing element. The apparatus provides a useful output signal despite the fact that signals at an intermediate point on the transmission line comprise the sum of incident and reflected waveforms. The voltage probe derives a signal from the transmission line that is representative of the sum of the incident and reflected waveforms. The current probe produces a voltage signal representative of the difference between the incident and reflected waveform currents. The summing circuit algebraically adds the output signals of the voltage and current probes, and produces an output signal representative of only one of the transmitted waveform or the reflected waveform.

Abstract: A cable television multi-tap system for forwarding signals to multiple customers from a main cable, and for receiving individual return signals from respective subscribers includes a printed circuit board secured to the inside face of the respective tap plates of a plurality of multi-taps, respectively, with each printed circuit board including at least first and second electrical receptacles for receiving a selected one of a plurality of first and second plug-in modules, respectively, said plurality of first plug-in modules providing different levels of directional coupling, respectively, and said plurality of second plug-in modules providing individually one or a combination of different levels of forward equalization, return path or backward equalization, cable simulation, high tap value filtering, high pass filtering, low pass filtering, band rejection, shunting, and noise filtering to optimize the signal quality of signals forwarded from the headend of the system to subscribers, and return signals from s

Abstract: A microstrip side-coupled directional coupler (20) uses inductive loading to achieve improved directivity. In one embodiment, short-circuited inductive stubs (26, 27) are connected to the coupled line (22) of the coupler (20). In a second embodiment, pairs of short circuited inductive stubs (34, 35) are connected respectively to the coupled line (32) and the primary transmission line (35) of a directional coupler (30). In a third embodiment, the primary transmission line (41) and the coupled line (42) of a coupler (40) are both centre loaded with short-circuited inductive stubs (43, 44) respectively.

Abstract: A structure for reducing the mutual inductance between two adjacent transmission lines on a substrate according to the invention includes a loop-shaped transmission line, at least one transmission line located on each side of the loop-shaped transmission line. One end of the loop-shaped transmission line is connected to bond wire and a diagonal end is connected to a signal output on the substrate. The loop-shaped transmission line has a short side equal to ½ of the wavelength of an input signal. With such structure, even though the clock frequency of a used CPU is several hundred MHz, the mutual inductance and cross-talk caused by the mutual inductance can be effectively reduced.

Abstract: A microwave/millimeter-wave integrated circuit (IC) realizes stable oscillation by reducing time-based variation of a load impedance. This IC connects an oscillator to an input terminal of a Lange coupler and connects to the isolation port of the Lange coupler a terminating resistor having a resistance equal to the load impedance connected to the output terminals of the Lange coupler. This connection stabilizes load impedance to the oscillator, and reduces variation in the oscillation frequency as a result of changes in load impedance.

Abstract: A broadband signal tap includes a reversible directional coupler and a make-before-break signal continuity bridge. The electronic circuitry of the directional coupler is provided on a daughterboard that is removably connected to a motherboard in the tap. The removable daughterboard has a plurality of symmetrically arranged connection means and the motherboard has a plurality of symmetrically arranged connection points for accepting connections with the plurality of symmetrically arranged outputs on the daughterboard. The connections on the motherboard and on the daughterboard are physically and functionally symmetrical, thereby permitting the daughterboard to be reversed. The daughterboard is maintained in a housing. The housing has elongated fingers which, when pushed downward onto the motherboard, penetrate through retaining holes in motherboard, thereby retaining the housing on the motherboard.

Abstract: An AC signal is switched between two circuit branches using a transformer or at least one directional coupler as a coupling device. Electronically controlled switches shunt one of two terminals of the coupling device to AC ground. The input signal is propagated out of the non-shunted terminal to one of the two circuit branches. The electronically controlled switches may be relays, transistors, or diodes. Diodes prevent the AC signal from being shunted to AC ground when reverse biased and shunt the AC signal to AC ground when forward biased.

Abstract: A direction coupler makes it possible to freely select an input terminal and an output terminal thereof. A branch unit (6) containing a branching circuit (6a) is mounted so that the branch unit (6) can be rotated relative to a mother board (5), with a central portion of the branch unit (6) being a fulcrum. Relay terminals (11, 12, 13, 14) of the mother board (5) are provided at positions corresponding to an input terminal (15) and an output terminal (16) of the branch unit (6).

Abstract: A wide band directional coupler of the type using ferrite cores and discrete winding in which a special winding method and its position on the core improves coupling flatness, directivity, as well as input and output VSWR.

Abstract: The present invention provides an electric device comprising two electric terminals, a button mechanism having a push button that can depressed to toggle between "on" and "off" statuses, and a conductive reed that conducts electric current between the two electric terminals when connected and disables the passage of current when disconnected. When the button is set "on", a reserve space exists between the reed and the button for the reed to spring upward without pushing the button upward. When the current passing through the reed exceeds a predetermined current level, the reed will become heated and spring upward and rest in the reserve space so as to electrically disconnect the two electric terminals.

Abstract: An RF directional coupler includes dual binocular ferrite cores. The dual cores are positioned back-to-back, such that the adjacent surfaces of each core contact each other. Each core has two generally cylindrical holes that extend through the core. Each hole preferably extends longitudinally through each respective core and is parallel to each other hole. One core is called the "main core" and the other core is called the "return core". Wire windings enter the coupler from the printed circuit board from the bottom of the coupler. A winding enters one hole in the main core and exits the hole on the top of the coupler. The winding then enters the corresponding hole in the return core from the top of the coupler. The winding then proceeds downwardly and exits the hole in the return core at the bottom of the coupler. After exiting the return core, the winding may then again enter the hole in the main core or may connected to a connection port on the printed circuit board.

Abstract: A directional coupler for r.f. power measurement utilizes a capacitive voltage divider connected to the center conductor of a length of transmission line. The output of the divider is connected to the input of a field effect transistor amplifier, which makes the divider essentially frequency independent over a wide frequency range. The outer conductor of the transmission line comprises two sections separated by a gap and connected to each other by an annular resistor permitting a current sample to be tapped. The annular resistor is disposed between two parallel circuit boards disposed in radial planes. Circuit components, including the field effect transistor amplifier are mounted on one of the boards. The output of the amplifier and the current sample are combined algebraically at a junction to provide a signal representing forward or reflected power in the transmission line.

Abstract: A directional coupler makes it possible to switch the input terminal and the output terminal thereof in position. A branch unit (5) containing a branching circuit (5a) is mounted so that the branch unit (5) can be rotated relative to a mother board (4), with a central portion of the branch unit (5) being a fulcrum. An input terminal (12) and an output terminal (13) are provided at positions corresponding to relay terminals (10, 11) of the mother board 4.

Abstract: A conducting housing (to be closed by a lid) for a coaxial cable distribution network has a common port and one of an aerial or pedestal port. A motherboard carries an RF circuit and a transfer switch. In one setting of the transfer switch the RF circuit connects a coaxial pin at the common port with a coaxial pin at the pedestal port. In the other setting the common port pin is connected to the aerial port pin. When the aerial port is used on a rectangular housing, a transmission line forms part of the RF circuit between the motherboard and the aerial port. The transmission is preferably a central conductor spaced over most of its length by air from an outer conductor in the form of an inverted U enclosing the central conductor on three sides. Preferably a ground plane on the back of the motherboard connects to the transmission line outer conductor to provide a path entry in the housing at both ends for ground currents generated by signals in the RF path.

Abstract: A directional coupler (300) is formed of a substrate (302) having a microstrip transmission line (304) and an inductor (306) seated perpendicularly across the microstrip transmission line. The windings (312) of the inductor (306) run parallel to the microstrip transmission line (304). One end (308) of the inductor (306) is terminated with a load (314) to reduce reflections while the other end (310) is coupled to a diode (316) and a capacitor (322) resonant at the frequency of interest and providing an output port for the coupler. The radio frequency (RF) signal is inductively coupled from the microstrip transmission line (304) to the windings (312) of the coil and converted through the diode (316) and the capacitor (322) to a voltage output (Vout) at the output port (324).

Abstract: In a CATV housing:the main RF circuit, a coupler circuit and splitter circuit are located respectively on a platform board, coupler board and splitter board respectively. The coupler board is between and perpendicular to the platform board attached to the housing and to the splitter board attached to the lid. The coupler circuit has a main RF circuit input and output near the bottom of the coupler board and a tap output to the splitter at the top of the board. A ground plane on the coupler board approximates, relative to the coupler circuitry, transmission line impedance. In combination with ground planes on the platform board and splitter board, the ground planes provide approximate transmission line impedance to both the main RF path and to the path through the coupler to the splitter output.

Abstract: A magnetic or electromagnetic circuit component includes an embedded magnetic material (e.g., ferromagnetic) in an HDI structure with alternating dielectric and metal or winding layers. In one embodiment, the ferromagnetic material is situated in a substrate well, or cavity, with or without an adhesive. Alternatively, the ferromagnetic material is co-fired with the ceramic substrate and then machined to achieve a required core shape. An electroplating process is employed to construct the metal layers, such process including differential plating for varying the thickness of metal layers and/or other portions of the circuit. Laser ablation or any other suitable technique is employed to make through-holes for insertion of the posts of a ferromagnetic core plate used to complete a magnetic circuit, if required. Advantageously, a magnetic or electromagnetic component may have a height of less than about 0.1 inch.

Abstract: A coupler device is disclosed which has an improved structure. The structure includes a substrate and, input ports and output ports disposed over the substrate. A plurality of inductors and capacitors are further included, which are arranged in a predetermined configuration and coupled between the ports. A layer of dielectric material is also disposed between the inductors and substrate which improves performance by reducing the dissipation losses and enhancing the frequency response of the coupler.

Abstract: In a CATV housing the main RF circuit, a coupler circuit and splitter circuit are located respectively on a platform board, coupler board and splitter board respectively. The coupler board is between and perpendicular to the platform board attached to the housing and to the splitter board attached to the lid. The coupler circuit has a main RF circuit input and output near the bottom of the coupler board and a tap output to the splitter at the top of the board. A ground plane on the coupler board approximates, relative to the coupler circuitry, transmission line impedance. In combination with ground planes on the platform board and splitter board, the ground planes provide approximate transmission line impedance to both the main RF path and to the path through the coupler to the splitter output.

Abstract: A hybrid including a substrate, a first dielectric layer, a ground metal, and a second dielectric layer, which are stacked in this order. Transmission lines are formed below and above the ground metal, and a slit is formed in the ground metal at a position corresponding to projection of the transmission lines onto the ground metal. The substrate has a greater dielectric constant than the dielectric layers. This makes it possible to prevent coupling between the upper and lower transmission lines, thereby implementing a high impedance, low loss transmission lines.

Abstract: A magnetic or electromagnetic circuit component includes an embedded magnetic material (e.g., ferromagnetic) in an HDI structure with alternating dielectric and metal or winding layers. In one embodiment, the ferromagnetic material is situated in a substrate well, or cavity, with or without an adhesive. Alternatively, the ferromagnetic material is co-fired with the ceramic substrate and then machined to achieve a required core shape. An electroplating process is employed to construct the metal layers, such process including differential plating for varying the thickness of metal layers and/or other portions of the circuit. Laser ablation or any other suitable technique is employed to make through-holes for insertion of the posts of a ferromagnetic core plate used to complete a magnetic circuit, if required. Advantageously, a magnetic or electromagnetic component may have a height of less than about 0.1 inch.

Abstract: A four port coupler includes a first port adapted to impedance match to a first impedance Z.sub.o, a second port adapted to impedance match to a second impedance Z.sub.1 different than the first impedance, a third port adapted to impedance match to the first impedance and a fourth port adapted to impedance match to the second impedance.

Abstract: A lumped element directional coupler tap is disclosed especially adapted for a system providing bi-directional communications. The directional coupler tap includes three resistors and a balun. A radio frequency signal may be tapped off of a main transmission line to feed a plurality of branch lines as in a cable television system. The coupler exhibits a high degree of isolation between tap and load ports, and good performance over an usually broad frequency range.

Abstract: A miniature directional coupler has short coupled lines, a series inductor and a parallel resistor connected to the second coupled line output. The coupled lines have a length considerably less than one quarter of a wavelength. Values of the series inductor and the parallel resistor are dependent on coupling, frequency, directivity, impedance and coupling flatness.