Abstract: A magnetic resonance isolator includes a ferrite member, a junction conductor that is arranged on the ferrite member and that includes a first port, a second port, and a third port, a permanent magnet that applies a direct current magnetic field to the ferrite member, a capacitor as a reactance element, and a mounting substrate. A main line arranged between the first port and the second port does not resonate, and an end of a sub-line branching from the main line defines the third port. The capacitor is connected to the third port and to the ground. The phase of a wave reflected from the sub-line is adjusted so as to be shifted by about 90 degrees at the intersection of the junction conductor.

Abstract: A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes first, second and third ports; a permanent magnet that applies a direct current magnetic field to the ferrite; a capacitor (or an inductor) that defines a first reactance element; and a capacitor (or an inductor) that defines a second reactance element. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. One of the capacitors is connected to the third port and the other capacitor is connected between the first port and the second port.

Abstract: A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes a first port, a second port and a third port; a permanent magnet that applies a direct current magnetic field to the ferrite; an inductor that defines a reactance element; and capacitors that define an impedance matching circuit. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. The inductor is connected to the third port and the capacitors are connected to the first and second ports, respectively.

Abstract: A non-reciprocal circuit element includes first and second isolators of a high-pass type, each of the first and second isolators including a permanent magnet, a ferrite body to which a direct-current magnetic field is applied by the permanent magnet, and first and second center electrodes arranged on the ferrite body so as to cross each other in an insulated state. The first isolator has a passing frequency band that is higher than a passing frequency band of the second isolator. The first and second isolators include input portions that are electrically connected to define a single input port. A low pass filter is provided between the input port and the input portion of the second isolator.

Abstract: In a circuit module, a core isolator includes a ferrite and a permanent magnet that is arranged to apply a direct-current field to the ferrite. A switch outputs to a signal path a high-frequency signal outputted from the core isolator. A SAW filter is provided on the signal path. A matching circuit is provided on the signal path and provides impedance matching between the output impedance of the core isolator and the input impedance of the SAW filter.

Abstract: An electromagnetic wave isolator (10) comprising a body (29) having an elliptical disk or ring shape such as to define two circular directions (D1, D2) of propagation. The body is further augmented by one or more feature (21, 22) lowering the symmetry of the isolator such that wave propagation is supported substantially more in one (D1) of the directions than in the opposite direction (D2). An integrated optics device includes two electromagnetic wave isolators.

Abstract: A waveguide circulator includes a waveguide junction made from a thermally conductive material and having three ports, and a ferrite cluster housed within the waveguide junction so as to be in communication with the ports. The ferrite cluster includes a plurality of ferrite segments extending from a central point of the ferrite cluster. Each ferrite segment is spaced apart from an adjacent ferrite segments by a gap. Thermal spacers made of a thermally conductive material are disposed in the gaps. Each thermal spacer is thermally coupled to the adjacent ferrite segments and the waveguide junction so as to conduct heat away from the adjacent ferrite segments to the waveguide junction. The ferrite cluster can also be used with other junction circulators including stripline junction circulators designed for high peak power applications.

Abstract: A method of fabricating an array of radiating elements includes on one layer or surface of a dielectric substrate, forming a first leg of a first resonator loop, on another layer or surface of the dielectric substrate forming a second leg of the first resonator loop between adjacent radiating elements, forming a via through the dielectric substrate, and metallizing the via forming a third leg of the first resonator loop interconnecting the first and second legs.

Abstract: Embodiments disclosed herein include methods of modifying synthetic garnets used in RF applications to reduce or eliminate Yttrium or other rare earth metals in the garnets without adversely affecting the magnetic properties of the material. Some embodiments include substituting Bismuth for some of the Yttrium on the dodecahedral sites and introducing one or more high valency ions to the octahedral and tetrahedral sites. Calcium may also be added to the dodecahedral sites for valency compensation induced by the high valency ions, which could effectively displace all or most of the Yttrium (Y) in microwave device garnets. The modified synthetic garnets with substituted Yttrium (Y) can be used in various microwave magnetic devices such as circulators, isolators and resonators.

Abstract: Provided is an electromagnetic wave isolator having at least one microstructured surface, which provides a change in electromagnetic properties across the depth of the microstructured surface.

Abstract: The present invention is directed to a surface mountable circulator/isolator device that includes a first dielectric layer having an electric circuit formed thereon. A second center dielectric layer is disposed adjacent the first dielectric layer, the center dielectric layer including an opening formed therein, the opening being aligned relative to the electric circuit. A ferrite element is disposed in the opening such that the ferrite abuts the electric circuit and is aligned in two-dimensions relative to the electric circuit. A third dielectric layer is disposed adjacent the second center layer. The third dielectric layer includes a ground plane formed on each major surface thereof. The first dielectric layer, the second center dielectric layer, the ferrite element, and the third dielectric layer are bonded together to form a laminated multi-layer structure. A permanent magnet is bonded to the second ground plane.

Abstract: A multi-junction stripline circulator, comprising a housing with a cavity structure and a plurality of stripline junction circuits stacked within the cavity structure and connected in a cascade arrangement. Each stripline junction circuit comprises a stripline conductor having a plurality of ports, where one of the ports is connected to a port of a stripline conductor of each consecutive junction circuit in a cascade arrangement, and a pair of ferrite elements sandwiching the stripline conductor therebetween. The multi-junction stripline circulator further comprises one or more center ground planes, each having radial arms connected to ground. Each of the center ground planes are disposed between two consecutive stripline junction circuits in said cascade arrangement.

Abstract: A non-reciprocal circuit device comprising a ground plate having pluralities of external projections, a resin member having a hole through which the ground plate is exposed, a garnet plate disposed in the hole of the resin member, a microstrip line member disposed on a main surface of the garnet plate, a partition member disposed on the microstrip line member, and a permanent magnet disposed on the partition member between a pair of metal cases in this order from bottom, at least part of the external projections of the ground plate extending through the hole of the resin member over an upper surface of the partition member, and being bent to enclose the garnet plate, the microstrip line member and the partition member.

Abstract: A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes a first port, a second port and a third port; a permanent magnet that applies a direct current magnetic field to the ferrite; an inductor that defines a reactance element; and capacitors that define an impedance matching circuit. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. The inductor is connected to the third port and the capacitors are connected to the first and second ports, respectively.

Abstract: A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes first, second and third ports; a permanent magnet that applies a direct current magnetic field to the ferrite; a capacitor (or an inductor) that defines a first reactance element; and a capacitor (or an inductor) that defines a second reactance element. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. One of the capacitors is connected to the third port and the other capacitor is connected between the first port and the second port.

Abstract: The present invention relates to a frequency-adjustable radio frequency (RF) isolator that may operate as a bandpass filter when processing RF signals in a forward direction and may operate as a notch filter when processing RF signals in a reverse direction. The notch filter has a notch frequency, which is adjustable to provide adequate isolation from reflected signals at a specific operating frequency. The frequency-adjustable RF isolator may include an electro-magnetic gyrator coupled to a variable impedance circuit, which may present a variable impedance to the electro-magnetic gyrator. The notch frequency may be dependent on the variable impedance. The notch filter may be a single-notch filter or may be a multiple-notch filter.

Abstract: A non-reciprocal circuit device includes a ferrite arranged to receive a direct-current magnetic field from a permanent magnet, a first central electrode and a second central electrode arranged on the ferrite. The non-reciprocal circuit device further includes matching capacitors and a terminating resistor. When high frequency signals flow in a reverse direction, power consumption at the first central electrode is increased by decreasing an equivalent parallel resistance Rp of the first central electrode, in relation to power consumption at the terminating resistor.

Abstract: A ferrite magnet device, a nonreciprocal circuit device, and a composite electronic component are provided. The ferrite magnet device includes a ferrite element having a plurality of central electrodes arranged to intersect one another in an electrically insulated state, and a pair of permanent magnets fixed to both main surfaces of the ferrite element so as to apply a direct current magnetic field to the ferrite element. The central electrodes are made of metal foils provided on both main surfaces of the ferrite element, with adhesive layers therebetween. Electrodes provided on the upper and lower surfaces of the ferrite element are formed by plating in through holes.

Abstract: A microwave circulator having an outer metal housing with a cavity containing at least one magnet and an annular centring arrangement interposed between the outside of the magnet and the cavity. The centring arrangement includes first and second solid metal rings, the two rings having cooperating inclined faces arranged such that when a force is applied to urge the centring arrangement along the cavity, one ring is displaced outwardly into intimate contact with the inside of the cavity.

Abstract: A surface mount circulator. The novel circulator includes a substrate, a predetermined number of microstrip lines disposed on a first surface of the substrate, a ground layer and a predetermined number of electrical contacts disposed on the second surface of the substrate, and a mechanism for coupling each microstrip line to one of the electrical contacts. In an illustrative embodiment, the circulator uses edge wrap metallization to wrap a microstrip line down a side of the substrate to connect with a corresponding contact. A ball grid array can then be used to connect the signal contacts and ground at the second surface of the substrate with a circuit board. The circulator also includes a magnet on first surface of the substrate over a resonator circuit connecting the microstrip lines and a pole piece on the second surface of the substrate beneath the ground to provide magnetic bias to the substrate.

Abstract: The invention relates to a non-reciprocal circuit element (1) having a plurality of strip conductor elements (2) insulated electrically from one another, which conductor elements are embedded in a multilayer core (3) of ferrimagnetic material and are arranged in superposed conductor planes in such a way that the conductor elements (2) cross over one another in at least one crossover area (4, 5). To provide such a circuit element, which is particularly cost-effective to produce and which is suitable in particular for use in mobile phones, the invention proposes that the core (3) comprises, at least in the crossover area of the conductor elements (2), hard magnetic material, which is permanently magnetized in a spatial direction perpendicular to the conductor planes.

Abstract: The invention relates to a non-reciprocal component comprising: a ferrite substrate having a first side and an opposing second side located on a ground layer, a first metal line and a second metal line are located on the ferrite substrate in parallel to each other. To provide a non-reciprocal component having small dimensions and which could be integrated. The ferrite substrate is magnetized parallel to the metal lines and each of the metal lines is running at least from one side of the ferrite substrate to the other side and back forming thereby at least one meander loop, wherein the loops are interlaced to each other and the metal lines are isolated in an area of the loop.

Abstract: A circulator/isolator housing is provided that includes body and a plurality of slots within the body configured to receive therethrough inserts having magnetic permeability. The housing further includes a plurality of receiving portions within the body corresponding to the plurality of slots and configured to maintain a position of the inserts.

Abstract: A nonreciprocal circuit device includes a ferrite-magnet element having ferrite provided with first and second central electrodes intersecting each other in an insulated manner and two permanent magnets arranged to sandwich the ferrite to apply a DC magnetic field thereto, a substrate on which the ferrite-magnet element and matching circuit elements are mounted, and a flat plate yoke. A first resin layer made of a cured liquid resin is provided at bonding portions of the ferrite-magnet element to the substrate, and a second resin layer made of a cured soft sheet-shaped resin adhered to a rear surface of the flat plate yoke is provided around the ferrite-magnet element and the matching circuit elements.

Abstract: The present invention is directed to a circuit assembly that includes an integrated circulator assembly. The circuit assembly has a first substrate, which contains a continuous circuit trace that includes a circulator component from the circulator assembly and at least one electrical component from the circuit assembly. A second substrate is disposed beneath the first substrate and includes a cladding on one surface. The second substrate contains an aperture that accepts a ferrite element, which is axially aligned with the circulator component of the circuit trace. A conductive material is placed across the ferrite element so that it forms a continuous ground plane with the cladding, which is common to the entire circuit trace. The circulator assembly also contains a magnet bonded to the ferrite element. The circulator assembly may also include a yoke disposed below the magnet to shield the circulator from external magnetic fields.

Abstract: A central conductor assembly for use in a non-reciprocal circuit comprising a first inductance element between a first input/output port and a second input/output port, and a second inductance element between the second input/output port and a ground port, a magnetic substrate being integrally provided with a first central conductor constituting the first inductance element and a second central conductor constituting the second inductance element; and the second central conductor being crossing the first central conductor on a main surface side of the substrate via a magnetic layer or a dielectric layer, with at least one end portion thereof bent such that high-frequency current flows therethrough in the same direction as or in an opposite direction to that of high-frequency current flowing through the first central conductor.

Abstract: A data transmitting circuit includes a reflection suppressive component generating circuit for generating a reflection suppressive component for suppressing the reflection caused by the discontinuity in the characteristic impedance on a transmission line, and a data output circuit for amplifying the reflection suppressive component and the data to be currently transmitted to a receiving side and outputting them to the transmission line.

Abstract: A non-reciprocal circuit device includes a yoke that is small-sized, has a simple structure, has sufficient adhesive strength, and can achieve favorable performance characteristics. The non-reciprocal circuit device includes a planar yoke, permanent magnets, a ferrite to which a DC magnetic field is applied by the permanent magnets, and first and second center electrodes located on the ferrite. The planar yoke is located on the upper surface of the ferrite-magnet assembly through an adhesive layer. On the rear surface of the yoke, protrusions are arranged in a lattice manner, and the protrusions increase the adhesive strength and facilitate the flow of a high-frequency field generated from the second center electrode.

Abstract: A nonreciprocal circuit device has a structure that allows a direct current magnetic field having an even density to be applied to a necessary portion of a ferrite without impairing a reduction in profile so as to improve insertion loss. The nonreciprocal circuit device, for example, a two-port isolator, includes permanent magnets, a ferrite to which a direct current magnetic field is applied by the permanent magnets, and a first center electrode and a second center electrode that are disposed on the ferrite. The permanent magnets are disposed so as to oppose principal surfaces of the ferrite. Portions of each of the permanent magnets opposing relay electrodes on top and bottom surfaces are preferably thicker than other portions thereof.

Abstract: A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is larger than the saturation magnetization of the center layer.

Abstract: A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is smaller than that of the center layer.

Abstract: A non-reciprocal circuit device capable of preventing and minimizing disturbances in magnetic field distribution in a ferrite to thereby improve insertion loss characteristics and isolation characteristics includes a ferrite to which a DC magnetic field is applied by permanent magnets and first and second center electrodes disposed on the ferrite. A conductive material is embedded in a recess provided in an end surface of the ferrite that is perpendicular or substantially perpendicular to the first and second principal surfaces of the ferrite, and the first and second center electrodes are electrically connected to the conductive material to define a circuit. Opening portions of the recess facing the first and second principal surfaces are arranged such that the opening portion at a downstream side of a direction of application of the DC magnetic field by the permanent magnets is larger than the opening portion at an upstream side thereof.

Abstract: A nonreciprocal circuit device attenuates unnecessary waves having a higher frequency than that of a fundamental wave, without increasing insertion loss. The nonreciprocal circuit device in the form of a 2-port type isolator includes a ferrite on which a first central electrode and a second central electrode are arranged to cross each other and so as to be electrically insulated from each other. A bypass circuit including a phase shifter and a filter is provided between an input port and an output port, and the bypass circuit does not allow signals in the fundamental wave band to pass through and also attenuates harmonics.

Abstract: An irreversible circuit element is configured by including a magnetic substance, a plurality of central conductors L1 to L3, one ends of which are connected to different input/output ports, arranged on the magnetic substance so as to intersect each other while being insulated from each other, a first conductor P1 connected to the other ends of all the central conductors L1 to L3, a second conductor, a plurality of matching capacitors (each configured by C1 to C3) connecting the one end of the central conductors L1 to L3 and the second conductor and a variable matching mechanism V1, one end of which is connected or integrated with the second conductor, capable of changing reactance between the one end and the other end thereof.

Abstract: A microwave circulator uses a thin-film exchange-coupled structure to provide an in-plane magnetic field around the circulator. The exchange-coupled structure is a ferromagnetic layer having an in-plane magnetization oriented generally around the circulator and an antiferromagnetic layer exchange-coupled with the ferromagnetic layer that provides an exchange-bias field to the ferromagnetic layer. A plurality of electrically conductive ports are connected to the exchange-coupled structure. Each of the portions or legs of the circulator between the ports may have an electrical coil wrapped around it with each coil connected to an electrical current source. The ferromagnetic resonance (FMR) frequency of the exchange-coupled structure in the absence of an external magnetic field is determined by the properties of the material of ferromagnetic layer and the magnitude of the exchange-bias field due to the exchange-coupling of the ferromagnetic layer to the antiferromagnetic layer.

Abstract: A non-reciprocal circuit element (for example, a 2-port isolator) includes a tabular yoke, permanent magnets, a ferrite to which a direct current magnetic field is applied from the permanent magnets, a first center electrode and a second center electrode disposed on the ferrite, and a circuit board. The tabular yoke is disposed on the upper surface of a ferrite magnet assembly with a dielectric layer therebetween. For example, the dielectric layer could be an adhesive agent layer made of an epoxy-based resin. The above arrangement provides a non-reciprocal circuit element having a simplified structure, a stable electrical characteristic, and a high reliability is provided.

Abstract: A nonreciprocal circuit device attenuates unnecessary waves having a higher frequency than that of a fundamental wave, without increasing insertion loss. The nonreciprocal circuit device in the form of a 2-port type isolator includes a ferrite on which a first central electrode and a second central electrode are arranged to cross each other and so as to be electrically insulated from each other. A bypass circuit including a phase shifter and a filter is provided between an input port and an output port, and the bypass circuit does not allow signals in the fundamental wave band to pass through and also attenuates harmonics.

Abstract: A multilayer metamaterial isolator and method of fabricating the same. A first layer or surface of a multilayer dielectric substrate includes a first leg of a first resonator loop. A second layer or surface of the multilayer dielectric substrate includes a second leg of the first resonator loop. A third leg of the first resonator loop extends through the multilayer dielectric substrate interconnecting the first and second legs of the first resonator loop.

Abstract: A circulator/isolator housing is provided that includes body and a plurality of slots within the body configured to receive therethrough inserts having magnetic permeability. The housing further includes a plurality of receiving portions within the body corresponding to the plurality of slots and configured to maintain a position of the inserts.

Abstract: A nonreciprocal circuit device has a structure that allows a direct current magnetic field having an even density to be applied to a necessary portion of a ferrite without impairing a reduction in profile so as to improve insertion loss. The nonreciprocal circuit device, for example, a two-port isolator, includes permanent magnets, a ferrite to which a direct current magnetic field is applied by the permanent magnets, and a first center electrode and a second center electrode that are disposed on the ferrite. The permanent magnets are disposed so as to oppose principal surfaces of the ferrite. Portions of each of the permanent magnets opposing relay electrodes on top and bottom surfaces are preferably thicker than other portions thereof.

Abstract: A non-reciprocal circuit device includes a yoke that is small-sized, has a simple structure, has sufficient adhesive strength, and can achieve favorable performance characteristics. The non-reciprocal circuit device includes a planar yoke, permanent magnets, a ferrite to which a DC magnetic field is applied by the permanent magnets, and first and second center electrodes located on the ferrite. The planar yoke is located on the upper surface of the ferrite-magnet assembly through an adhesive layer. On the rear surface of the yoke, protrusions are arranged in a lattice manner, and the protrusions increase the adhesive strength and facilitate the flow of a high-frequency field generated from the second center electrode.

Abstract: A non-reciprocal circuit device includes a ferrite arranged to receive a direct-current magnetic field from a permanent magnet, a first central electrode and a second central electrode arranged on main surfaces of the ferrite. Electrodes are provided in recesses provided on both top and bottom surfaces of the ferrite. These electrodes are soldered to terminal electrodes provided on a circuit board and include a countermeasure to prevent the electrodes from detaching from the recesses when a pulling force is applied to a joining portion therebetween.

Abstract: A waveguide circulator comprising at least three waveguide arms intersecting at a junction, at least one ferrite element positioned within the junction, an impedance transformer and a recessed transformer. At least a portion of each of the at least three waveguide arms and the junction define a first wall and a second wall that are positioned in an opposing relationship. The impedance transformer is positioned in proximity to the at least one ferrite element and projects from the first wall. The recessed transformer is positioned in proximity to the impedance transformer and is recessed within the first wall.

Abstract: A non-reciprocal circuit device includes a ferrite arranged to receive a direct-current magnetic field from a permanent magnet, a first central electrode and a second central electrode arranged on the ferrite. The non-reciprocal circuit device further includes matching capacitors and a terminating resistor. When high frequency signals flow in a reverse direction, power consumption at the first central electrode is increased by decreasing an equivalent parallel resistance Rp of the first central electrode, in relation to power consumption at the terminating resistor.

Abstract: A non-reciprocal circuit device comprising a first inductance element disposed between a first input/output port and a second input/output port; a second inductance element disposed between the second input/output port and the ground; a first capacitance element constituting a first parallel resonance circuit with the first inductance element; a resistance element parallel-connected to the first parallel resonance circuit; a third inductance element series-connected between the second inductance element and the ground; and a second capacitance element constituting a second parallel resonance circuit with the second and third inductance elements.

Abstract: A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is larger than the saturation magnetization of the center layer.

Abstract: A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is smaller than that of the center layer.

Abstract: A non-reciprocal circuit device capable of preventing and minimizing disturbances in magnetic field distribution in a ferrite to thereby improve insertion loss characteristics and isolation characteristics includes a ferrite to which a DC magnetic field is applied by permanent magnets and first and second center electrodes disposed on the ferrite. A conductive material is embedded in a recess provided in an end surface of the ferrite that is perpendicular or substantially perpendicular to the first and second principal surfaces of the ferrite, and the first and second center electrodes are electrically connected to the conductive material to define a circuit. Opening portions of the recess facing the first and second principal surfaces are arranged such that the opening portion at a downstream side of a direction of application of the DC magnetic field by the permanent magnets is larger than the opening portion at an upstream side thereof.

Abstract: A multilayer metamaterial isolator and method of fabricating the same. A first layer or surface of a multilayer dielectric substrate includes a first leg of a first resonator loop. A second layer or surface of the multilayer dielectric substrate includes a second leg of the first resonator loop. A third leg of the first resonator loop extends through the multilayer dielectric substrate interconnecting the first and second legs of the first resonator loop.

Abstract: A method detects relaying of a contactless data communication by a radio amplifier for intercepting and manipulating the communication to achieve an unauthorized authentication. The method involves transmitting an electromagnetic field successively from at least two spatially separated antennas of a transmitting unit, receiving the transmitted fields in a receiving unit, determining field strength vectors of the received fields allocated to each antenna, and comparing actual values of the vectors with prescribed nominal values stored in a nominal value field that maps the true field strength distribution in multi-dimensional space around the transmitting unit. The actual field strength magnitude and the reception angle between the transmitting antennas can be determined from the vectors and compared with stored nominal values in this manner. When the determined actual values match prescribed nominal values of the nominal value field, the occurrence of a relaying of the signal can be reliably excluded.