Abstract: A symmetric dual direction coupler has a layout that is controlled such that there is an axis of symmetry between ports and that any switches used within the dual direction coupler are also symmetrical. That is, for a dual direction coupler having a transmitted port, an input port, an isolated port, and a coupled port with switches used to control forward mode or reverse mode for the coupler, the transmitted port and the input port are symmetrical across the axis of symmetry; the isolated port and coupled port are symmetrical across the axis of symmetry; and the switch layout is symmetrical across the axis of symmetry.

Abstract: The present application provides a trisection power divider with isolation and a microwave transmission system, where the divider includes a first hybrid ring coupler with a distribution ratio of 1:2 and a second hybrid ring coupler with a distribution ratio of 1:1; a first port of the first hybrid ring coupler is a signal input port; a second port of the first hybrid ring coupler is connected with a first port of the second hybrid ring coupler; a second port of the second hybrid ring coupler, a third port of the second hybrid ring coupler and a third port of the first hybrid ring coupler are three signal output ports of the divider; and the second port of the first hybrid ring coupler is a port with high power.

Abstract: According to one embodiment, an inductive coupling system includes a first inductor and a second inductor. The first inductor includes a first wiring pattern provided on a first board and shaped as an open loop. The second inductor includes a second wiring pattern provided on a second board and shaped as an open loop. The second inductor is inductively coupled to the first inductor. A width of the second wiring pattern is narrower than a width of the first wiring pattern.

Abstract: A full duplex system includes a first port connected to an antenna, a second port connected to a source of a signal to be transmitted via the antenna, and a third port for outputting a signal received via the antenna. The tuneable rat-race coupler includes a plurality of arms, and a variable phase shifting and attenuation circuitry in a first arm of the plurality of arms to enable cancellation at the third port of a reflected signal produced by the antenna.

Abstract: A phase shifter device is disclosed and comprises a continuous transmission line on a substrate, and a plurality of ports coupled to the continuous transmission line and spaced apart from each other around the continuous transmission line. The plurality of ports comprises a first port, a second port, a third port, a fourth port, and a fifth port. A radio frequency (RF) switch is operative to connect either the first port or the fifth port to a main RF line that is coupled to one or more antennas. The second port is located between the first port and the third port, and the fourth port is located between the fifth port and the third port. In an alternative embodiment, the phase shifter device is combined with a circular polarization quadrature divider.

Abstract: An annual directional coupler having at least three taps, which are each arranged relative to one another around routes having a wavelength difference of ¼ of a wave guide wavelength, includes in particular at least two branch lines, wherein a first branch line has at least three taps and wherein the at least second branch line does not have any taps and is supplemented by an additional route corresponding to the wave guide wavelength.

Abstract: A Base Transceiver Station (BTS) and a method for wireless communication with a User Equipment (UE) in a wireless communication system. The BTS comprises a Multiple Input Multiple Output (MIMO) antenna array configured for beamforming and MIMO transmission. The BTS further comprises a processing circuit, configured for supporting same or separate downlink precoding for a control plane and a user plane by modifying phase excitation of the MIMO antenna array and causing a transceiver to create an antenna beam by providing different phase for each antenna element of the MIMO antenna array. The BTS also comprises a transceiver, configured for transmitting a signal in the antenna beam via the MIMO antenna array, to be received by the UE.

Abstract: Antenna units, antenna systems and polarizing systems provide polarization diversity to leaky-wave antennas. An antenna unit comprises a rat-race coupler having a summation port, a difference port and two output ports. Each one of a pair of composite right/left-handed (CRLH) leaky-wave antennas (LWA) is connected at one end to a respective one of the output ports of the rat-race coupler. An inductive stub is implemented between the CRLH LWAs for connecting the CRLH LWAs to a grounded via. Various polarizations are obtained by injecting a radio-frequency (RF) signal in the summation or difference port of the rat-race coupler, or in both ports. System variants include various devices and assemblies for injecting RF signals in the antenna unit. One such variant includes a polarizing system having a switched matrix for directing a signal according to various intended polarizations.

Abstract: A waveguide antenna assembly and process for transceiving signals of a predetermined radio frequency range comprising at least two collaterally aligned conductive layers configured in a conformable loop so as to form an electrically isolating channel dimensionally configured for support of the waveguide modes of the predetermined frequency range, an aperture for electromagnetically transceiving the signals, wherein the aperture extends along a surface of the electrically isolating channel such that the aperture extends between the outer edge of the inner surface of the first conductive layer and the second conductive layer, a back short spaced apart from the aperture a predetermined distance equal to a resonant length of the waveguide mode wavelength so as to provide a circuit impedance between the first conductive layer and the second conductive layer for tuning the waveguide to transceive the signals, and excitation points coupled to the aperture to propagate waveguide modes within the electrically isolatin

Abstract: Lumped-element based class-E Chireix combiners are disclosed that are equivalents of a quarter-wave transmission line combiner. The proposed class-E equivalent power amplifier circuits that are used can be derived from a parallel tuned class-E implementation. The proposed low-pass equivalents can behave similarly in terms of class-E performance, but absorb the 90 degree transmission line.

Abstract: A coupling structure for crossing three transmission lines millimeter-wave or centimeter-wave signals a signal conductor layer of a circuit substrate, the coupling structure comprising three planar cross-couplers, and from each of the three cross-couplers two input/output points of the cross-coupler being connected clockwise in succession in the plane of the cross-coupler, to respectively one input/output point of a respective other of the three cross-couplers.

Abstract: High power RF energy supplied to a reaction chamber at a resonant frequency is used to break the covalent bonds of a hydrocarbon material without heat. An RF signal generator may be used to supply RF energy to a resonant ring through a four port coupler. The phase of the RF energy passing through the resonant ring may be adjusted to achieve an integral multiple of a resonant wavelength. Wavelength and intensity may be adjusted to sublimate or pyrolyze the hydrocarbon material to yield a useful gaseous product.

Abstract: One embodiment relates to a coupler that can be used in a radar system. The coupler includes differential ports, an antenna port, a receiver port, a local port and a transmission path. The differential ports are configured to receive a differential signal. The antenna port is configured to output a transmitted signal and to input a received signal. The transmitted signal is derived from the differential signal. The receiver port is configured to output a portion or version of the received signal. The local port outputs a local signal, which is also derived from the differential signal. The transmission path is coupled to the differential ports, the antenna port, the receiver port and the local port. The transmission path typically has a length selected to derive or output the signals at the above ports.

Abstract: An electromagnetic resonance coupler including: a transmitting resonator provided on a transmission substrate and having an open loop shape having an opening, first wiring provided on the transmission substrate and connected to a first connection point on the transmitting resonator, a receiving resonator provided on the reception substrate, second wiring provided on the reception substrate and connected to a second connection point on the receiving resonator, and third wiring provided on the reception substrate and connected to a third connection point on the receiving resonator. When viewed in a direction perpendicular to a main surface of the transmission substrate, the transmission substrate and the reception substrate are provided facing each other so that the transmitting resonator and the receiving resonator are symmetric about a point and have matching contours.

Abstract: An apparatus is provided. First and second hybrid couplers are provided with each having a first port, a second port, a third port, a fourth port and with each being substantially curvilinear. The fourth ports of the first and second hybrid couplers are first and second isolation port that are mutually coupled. The first port of the first hybrid coupler is configured to carry a first portion of a differential signal, and the first port of the second hybrid coupler is configured to carry a second portion of the differential signal.

Abstract: A compact multi-band hybrid ring (rat-race) coupler utilizing a ring of composite right-handed and left-handed (CRLH) transmission lines (TLs) and multiple ports, provides miniaturization and the ability to operate at arbitrary frequency bands unlike conventional couplers. The hybrid ring is made compact, such as by constraining phase delay contributions |?1|, |?2|?270°. The coupler can be used in many applications, for example as a mode decoupling network in a dual-band front-end MIMO system. The inclusion of a CRLH delay line is also described which alters the phase relationship of the signals and is particularly well suited for extending pattern diversity in response to frequency.

Abstract: A diplexing apparatus and method which utilizes composite right/left-handed (CRLH) phase-advance/delay lines combined with a coupler. By engineering CRLH-based transmission lines with desired phase responses at two arbitrary frequencies of interest, the connected CRLH delay line and/or CRLH coupler are excited in a manner such that signals at designated frequencies are separated to the corresponding output ports of the hybrid coupler. Benefits of the apparatus include elimination of design complexities such as optimization of the interconnection junctions and the harmonic spurious suppression involved in conventional filter-based diplexers. In addition, channel isolation is beneficially achieved from the isolation property of directional couplers. Measured insertion loss on the implementations was found to be less than 1 dB, with isolation greater than 20 dB in the dual bands. A high level of agreement was observed between simulated and measured results.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: Embodiments are directed to a RF combiner/splitter having a first port separated from a second port and a third port by a generally tapering microstrip section. The second and third ports are separated by a generally rectangular bridge bar having a width selected to match the impedance of devices to be connected to the second and third ports and a length selected to provide a separation between the second and third ports of approximately quarter wavelength at a center point of an operational frequency of the devices. In a first embodiment, a horizontal RF choke joint is positioned between the first port and the tapering section. In a second embodiment, one choke joint is positioned between the second port and the bridge bar and a second choke joint is positioned between the third port and the bridge bar.

Abstract: A transient voltage suppressing (TVS) circuit with uni-directional blocking and symmetric bi-directional blocking capabilities integrated with an electromagnetic interference (EMI) filter supported on a semiconductor substrate of a first conductivity type. The TVS circuit integrated with the EMI filter further includes a ground terminal disposed on the surface for the symmetric bi-directional blocking structure and at the bottom of the semiconductor substrate for the uni-directional blocking structure and an input and an output terminal disposed on a top surface with at least a Zener diode and a plurality of capacitors disposed in the semiconductor substrate to couple the ground terminal to the input and output terminals with a direct capacitive coupling without an intermediate floating body region.

Abstract: The present invention provides a complementary-conducting-strip (CCS) structure for miniaturizing microwave transmission line. The CCS structure comprises a substrate; a transmission part formed on the substrate, the transmission part consisted of M metal layers and at least one connecting arm extending from the metal layers to connect to an adjacent CCS structure, the M metal layers interlaminated M?1 dielectric layer(s) perforating a plurality of first metal vias to connect the M metal layers, wherein M?2 and M is a nature number; and a frame part formed on the substrate, the frame part surrounding the transmission part and consisted of M?1 metal frame(s), the M?1 metal frame(s) interlaminated M?2 dielectric frame(s) perforating a plurality of second metal vias to connect the metal frames.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: A compact multi-band hybrid ring (rat-race) coupler utilizing a ring of composite right-handed and left-handed (CRLH) transmission lines (TLs) and multiple ports, provides miniaturization and the ability to operate at arbitrary frequency bands unlike conventional couplers. The hybrid ring is made compact, such as by constraining phase delay contributions |?1|, |?2|?270°. The coupler can be used in many applications, for example as a mode decoupling network in a dual-band front-end MIMO system. The inclusion of a CRLH delay line is also described which alters the phase relationship of the signals and is particularly well suited for extending pattern diversity in response to frequency.

Abstract: An electronically tuned, absorptive, low-loss notch filter with high RF power handling capability is obtained using a four-port quadrature hybrid coupler connected to a matched pair of band pass resonator devices and resistive terminations. The notch filter design uses series-only tuning elements for the band pass resonator devices to raise the RF power handling of the band pass resonators far above conventional techniques while also being tunable at high speeds. The notch filter architecture and method can be used for interference cancellation in a wide range of wireless technologies, such as cellular phone, wireless routers, hand-held radios, satellite communications, and any other environments where there are a number of wireless technologies in close signal proximity.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: A multi-port reconfigurable coupler includes a coupler and a switching system configured to selectively reconfigure multiple ports of the coupler for increased application flexibility and for efficiently transmitting and receiving radio-frequency signals. The multi-port reconfigurable coupler includes a transmit signal port, a termination port, a receive signal port, an antenna port, and a switching system configured to selectively couple the termination port to a predetermined termination potential based on information indicating one of a transmit only mode, and a receive only mode, and to decouple based on information indicating a transmit-receive mode.

Abstract: A compact multi-band hybrid ring (rat-race) coupler utilizing a ring of composite right-handed and left-handed (CRLH) transmission lines (TLs) and multiple ports, provides miniaturization and the ability to operate at arbitrary frequency bands unlike conventional couplers. The hybrid ring is made compact, such as by constraining phase delay contributions |?1|, |?2|?270°. The coupler can be used in many applications, for example as a mode decoupling network in a dual-band front-end MIMO system. The inclusion of a CRLH delay line is also described which alters the phase relationship of the signals and is particularly well suited for extending pattern diversity in response to frequency.

Abstract: Four variable reactance means are connected, respectively, to the four ports of a quadrature hybrid circuit which is composed of four ring-linked two-port circuits each composed of a transmission line or multiple lumped reactance elements, so that by changing the reactance values of the four variable reactance means, operating frequency of the quadrature hybrid circuit can be selectively changed.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.

Abstract: An antenna includes first, second and third waveguides in direct communication with a base waveguide at first, second and third positions, respectively, the base waveguide forming a continuous loop. The second position, at which the second waveguide is in direct communication with the base waveguide, is spaced apart from the first position by about one-sixth the circumference of the loop. The third position, at which the third waveguide is in direct communication with the base waveguide, is spaced apart from the first position by about one-sixth the circumference of the loop, and is uninterruptedly spaced apart from the second position, without extending through the first position, by about two-thirds the circumference of the loop. The first, second and third waveguides comprise closed-channel waveguides, and the second and third waveguides have an open end and are configured to radiate electromagnetic waves and/or focus radiating electromagnetic waves.

Abstract: A direct current (DC) isolated phase inverter and a ring hybrid coupler including the DC isolated phase inverter is provided. The ring hybrid coupler including the DC isolated phase inverter comprising: a first, second, third and fourth transmission line arm; a first port connected to the first arm, second port connected to the second arm, third port connected to the third arm and fourth port connected to the fourth arm; and a DC phase inverter inserted within one of the first, second, third and fourth arms, wherein the DC phase inverter comprises: a transmission line comprising a plurality of signal and ground traces, wherein the plurality of signal and ground traces are interchanged; and a plurality of capacitors disposed in series with the ground traces, wherein the plurality of capacitors isolate the DC phase inverter from a device connected to the transmission line.

Abstract: A directional coupler includes a conductor pattern formed on a substrate. The conductor pattern includes first to fourth lines radially extending from a predetermined point on the substrate, and conductive pattern portions. Each line has a first point a first distance from the predetermined point, and a second point a second distance from the predetermined point, wherein the first and second distances have different values. Respective first or second points of adjacent lines are connected by curves, straight lines, or bent lines with obtuse angles, and the crossing angle defined at an intersection of the connecting lines and edges of adjacent lines is obtuse. The conductive pattern portions are defined by the first to fourth lines and the connecting lines. The conductive pattern portions break degeneracy of a plurality of resonant modes.

Abstract: A coupler includes a first set of ports coupled to a first ring, a second set of ports coupled to a second ring, and a plurality of connecting elements coupled between the first and second rings. The coupler provides low loss insertion and high port isolation and may be used as a standalone coupler or as an elementary device for building Butler matrices of varying configurations.

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 material may be removed from the top electrode of a film bulk acoustic resonator to alter the mass loading effect and to adjust the frequency of one film bulk acoustic resonator on a wafer relative to other resonators on the same wafer. Similarly, the piezoelectric layer or the bottom electrode may be selectively milled with a focused ion beam to trim the resonator.

Abstract: A rat race circuit has an annular transmission line formed on a microstrip dielectric substrate. A terminal for port 1 is formed at any given position of the annular transmission line. Respective terminals for port 2 and port 3 are formed at respective positions distant from the position of port 1 in the counter-clockwise and clockwise directions each by a distance of ?g/4 (?g: effective wavelength). Moreover, at the position distant from the position of port 2 in the counter-clockwise direction by the distance of ?g/4, a terminator resistor (R=50?) is formed. A local oscillator signal is supplied to port 1, and first and second mixer inputs are connected respectively to port 2 and port 3. The local oscillator signal divider and a low noise converter using the divider are thus provided that are scarcely influenced by matching with respect to mixers and provide stable performance and high isolation.

Abstract: A coupler includes a first set of ports coupled to a first ring, a second set of ports coupled to a second ring, and a plurality of connecting elements coupled between the first and second rings. The coupler provides low loss insertion and high port isolation and may be used as a standalone coupler or as an elementary device for building Butler matrices of varying configurations.

Abstract: The invention relates to a wideband 180° microwave phase switch structure, consisting of microwave or millimetric wave elements such as waveguides, microstrips, striplines or coaxial cables, which are connected in such a way that they can produce a structure with a 180° phase difference between the two possible low-loss outputs in the band width used, with a high band width, flat phase and balanced amplitude. The structure disclosed in the invention is based on interconnection of two hybrid rings (“magic T”) that are embodied according to a given configuration of the different ports of the two rings, thereby providing a unique structure resulting in a practical application device with a 180° phase difference and given properties relative to the length of the waves and the impedances relative to the resulting lines.

Abstract: A line driver for coupling a data transceiver to a transmission line having a load impedance via a transformer with a turns ratio of 1:n includes an input port for receiving an input signal voltage from the data transceiver, an output port for supplying an output signal voltage to the transformer, and an amplifier circuit for amplifying the input signal voltage. The amplifier circuit includes a first output stage, a second output stage coupled to the output port, an output resistor coupled to the first output stage, a feedback path from the first output stage to an input of the amplifier circuit, and a line matching network coupled between the first output stage and the second output stage, for compensating variations in the load impedance, so that a synthesized output impedance of the line driver substantially matches an actual load impedance Z of the transmission line.

Abstract: A phase shifter includes a first rat-race ring having four ports, an input coupled to a first one of the ports, an output coupled to a second one of the ports, a first resonant circuit coupled to a third one of the ports, and a second resonant circuit coupled to a fourth one of the ports, each of the first and second resonant circuits including a tunable dielectric varactor. The first rat race ring can be connected to another phase shifting stage including a second rat race ring or a digital switched line phase shifter.

Abstract: A balancing/unbalancing (balun) structure includes a microstrip line printed circuit board (PCB). Two input ports are coupled to a differential signal. An isolated port is connected to ground through a resistance. An output port is coupled to a single-ended signal corresponding to the differential signal. A plurality of traces on the PCB connect the two input ports, the load connection port and the output port, wherein distance between adjacent traces is approximately twice PCB thickness.

Abstract: Switchable path length coupler/dividers. Coupler/divider operation over multiple frequency bands is provided by using switchable path lengths. In one implementation, a Wilkinson-style device with switches to select different path lengths and therefore operating frequencies. In a rat-race style device, switches select races of different lengths, and therefore operating frequencies.

Abstract: A printed board having a structure for equalizing propagation times on transmission lines connecting the same pair of circuit elements at several terminals. The structure controls each propagation delay by connecting each transmission line partially in different dielectric layers having different dielectric constants in a multi-layered printed board regardless of a distance between the terminals to be connected.

Abstract: The prior art has a problem in which an isolation between output terminals is deteriorated when a thin film resistor is used as an isolation resistor. Such being the case, in a power divider/combiner comprising an input terminal, two output terminals, two branch lines each connecting the input terminal and one of the output terminals and having a line length that is ¼ of a set wavelength or a multiple of integer of half a wavelength and ¼ of the set wavelength, and an isolation resistor connected to between the output terminals, there is provided an improved power divider/combiner further comprising a transmission line interposed between each of the output terminals and the branch lines. Consequently, even when using the isolation resistor having a length that can not be ignored as compared with a wavelength of a high-frequency signal in use, the isolation between the output terminals can be ensured.

Abstract: A monopulse source for a focal feed antenna including at least two waveguides machined in a metal flange supporting a microwave transmission and reception circuit of the antenna, and a dielectric substrate on the metal flange. Also included is a microwave short-circuit having an opening with a smaller dimension than a dimension of a respective waveguide. The microwave short-circuit is mounted on the dielectric substrate such that an axis of the microwave short-circuit coincides with an axis of the respective waveguide. Further, a transition positioned on the dielectric substrate and within the opening of the microwave short-circuit is configured to couple the respective waveguide.

Abstract: A broadband modem hybrid transformer couples a broadband modem to a plain-old-telephone (POTs) line. The hybrid includes a full bridge having an impedance matching network to reduce the transhybrid attenuation of the hybrid. The second matching network(s) include various resistive and reactive components which together provide an impedance value selected based upon the impedance of the telephone line typically reflected into the primary windings of the transformer. The matching network increases the transhybrid attenuation of the hybrid, and thus reducing the amount of noise which couples from the modem transmit circuit to the modem receive circuit through the hybrid.

Abstract: An arrangement for transferring high frequency microwave signals between a cable and a microstrip printed circuit on a dielectric substrate is disclosed wherein a first microstrip track on a first substrate reactively couples with a second microstrip track on a second substrate, which second substrate is connected to an inner conductor of a coaxial cable and a ground plane associated with the first microstrip track is connected to the ground shielding of the coaxial cable. Since the microwave signals are reactively coupled by means of printed circuit tracks on a first dielectric substrate to printed circuit tracks on a second dielectric substrate, a non-contacting RF connection is established. This avoids the potential formation of intermodulation products which occur in metal--metal (galvanic) junctions. A further, advantage arises in that a d.c. block is automatically incorporated within the arrangement, reducing the need for separate coupled lines, capacitors and the like.

Abstract: A motion detection unit for detecting motion by means of Doppler frequency shift which comprises: a microwave circuit board comprising an oscillator, a hybrid coupler circuit element and a mixer; an antenna board comprising at least one transmit and receive antenna; and a ground plane layer, the two boards being superimposed with the ground plane layer intervening, wherein, in operation, the hybrid coupler circuit element divides power from the oscillator into power for the antenna transmission signal and local oscillator (LO) power to the mixer, and directs a received signal from the antenna to the mixer, the local oscillator (LO) power and the received signal being combined in the mixer to produce a Doppler signal output.