Abstract: A microstrip antenna providing circularly polarized radiation formed by two layered cavities with two rectangular conductive patches. A first cavity s formed by a ground plane and a first rectangular conductive patch having a lateral dimension and coupling holes placed therein. A second cavity is formed between the first rectangular conductive path and a second rectangular conductive patch having a longitudinal dimension. The longitudinal dimension of the second rectangular conductive patch is essentially equal to the lateral dimension of the first rectangular conductive patch. The second rectangular conductive patch is coupled through the coupling holes to the first rectangular conductive patch, resulting in circularly polarized radiation. The circularly polarized antenna can easily be manufactured using conventional microstrip techniques. Additionally, bandwidth and power are improved.

Abstract: An inventive rearview mirror assembly is disclosed in which a microwave antenna is mounted so as to receive transmissions from one or more satellites through the front windshield of the vehicle. The microwave antenna may be tuned to receive satellite transmissions from a position identification system constellation of satellites, such as GPS or GLONASS. Additionally, the microwave antenna may be tuned to alternatively or additionally receive transmissions from at least one communication satellite, such as a CD radio satellite. In addition to the inventive rearview mirror assembly, an inventive electrical control system is disclosed that may be used as a navigation system, an electrochromic rearview mirror control system, a head lamp control system, a tire pressure monitoring and display system, a temperature sensing and display system, a vehicle compass system, a vehicle data recorder system, and/or a vehicle odometer verification system.

Abstract: A single antenna assembly receives both direct broadcast satellite signals (DBS) and terrestrial broadcast signals, such as local VHF and UHF television channel broadcasts. The assembly includes an electromagnetic signal reflector for reflecting and focusing electromagnetic signals in a first band of frequencies, such as microwave signals for DBS. Incorporated in the reflector is an antenna for receiving electromagnetic signals in a second band of frequencies.

Abstract: The present invention overcomes the above-identified deficiencies in the art by providing a miniature, built-in dual band antenna which is suitable for use in future compact mobile terminals. According to exemplary embodiments, a built-in antenna is provided which includes two spiral conductor arms which are of different lengths and capable of being tuned to different frequency bands. The spiral arms are mounted on the mobile terminal's printed circuit board via a substrate. Matching of the antenna is performed by a matching bridge which is positioned between a feeding pin and grounded post. By adjusting the length of the matching bridge, the matching of the antenna can be changed. In an alternative embodiment, a loading resistor is attached to the matching bridge in order to enhance the bandwidth of the antenna.

Abstract: A multi-tile configured, two-dimensional phased array antenna architecture is configured of an gridwork of sub-array `tiles`, each of which contains a mechanically integrated and RF-integrated antenna elements and RF interface components therefor. Each tile is formed of a multilayer printed wiring board and supports a sub-array of antenna elements and their associated RF circuits, so that the tile itself is effectively an operative phased-array antenna. The gridwork supports the sub-array tiles in sealed engagement with the framework, whereby associated RF networks components at rear sides of the tiles are protected against the free space environment to which the antenna elements on front faces of the tiles are exposed. Each RF interface network contains signal processing circuitry for controlling the operation of a respective one or a set of the antenna elements on the front side of the tile.

Abstract: The present invention is a microstrip antenna which produces ultrawide band leaky wave radiation. The antenna produces leaky wave radiation, then trs the leaky wave radiation to produce an ultrawide bandwidth. The antenna includes tapered metal patches which taper the radiation. The antenna gives an ultrawide bandwidth performance of greater than a 4:1 ratio.

Abstract: The present invention relates to a wireless local loop (WLL) system using a patch-type antenna which is provided with microstrips and can be installed indoors. In a WLL system wherein there are provided a base station for relaying transmitted/received signals and a terminal for exchanging these signals between the base station and a telephone or a modem. The present invention includes a patch-type antenna that is detachable/connectable from/to the terminal.

Abstract: A circularly polarized cross dipole antenna according to the present invention comprises a first L-shaped dipole antenna element including a first pair of strip conductors and a first bending portion and a second L-shaped dipole antenna element including a second pair of strip conductors and a second bending portion. The first L-shaped dipole antenna element is arranged in a first region of four regions delimited by crossing lines virtually set within a single plane and the second L-shaped dipole antenna element is arranged in a second region thereof which is diagonally opposite to the first region. The first bending portion and the second bending portion are close and opposite to each other such that the first and second L-shaped dipole antenna elements form a cross. The antenna also comprises a parallel-twin-line feeder extended from the first and second bending portions and provided so as to feed power within the single plane.

Abstract: An antenna is formed from a metal sheet partitioned by a slot. A corner of the metal sheet is short-circuited, and a field is coupled to the antenna near to the short circuit corner. The slot extends from a point near the field, across the metal sheet to an opposite corner to the short circuit corner. The metal sheet may be supported over air, or by a solid dielectric substrate.

Abstract: An antenna system includes a first support member having a first pair of opposed planar support surfaces and a second support member having a second pair of opposed planar support surfaces. The first and second support members are coupled along a common edge and oriented such that the first pair of planar support surfaces are substantially orthogonal to the second pair of planar support surfaces. At least one antenna element is mounted to each of the support surfaces of the first and second pairs of support surfaces.

Abstract: To control the temperature sensitivity of a ferroelectric microwave device, a microwave waveguide in the device is loaded with a modified ferroelecc material of reduced grain size less than 100 nm, preferably about 50 nm. The electrical properties of this material are less sensitive to temperature change. Thus, when a dc bias voltage is applied across the ferroelectric to tune the dielectric constant, changes in temperature will have a minimal effect on the desired tuning of the device.

Abstract: A quadrifilar crank slot antenna for GPS receivers. The antenna has a cylindrical dielectric body covered with a conductive coating. Four crank shaped slots are formed in a helical pattern in the antenna and extend around one half of its circumference to provide a right hand circular polarization for receiving GPS signals. A microstrip feed system is provided and is arranged to create balanced currents along both sides of each slot so that the impedance transformation is not adversely affected.

Abstract: A linear antenna, such as a monopole antenna, is placed in the axis of a circular polarized antenna, such as a printed patch antenna or a helical antenna. The linear antenna can be optimized for a terrestrial communication system while the circular polarized antenna can be optimized for a satellite system.

Abstract: A cavity backed slot antenna comprises a conductive cavity, a conductive film carried by a thin dielectric substrate which is above the cavity. The conductive film includes one or more slots which an electric field is applied to radiate an electromagnetic energy.

Abstract: A low-profile antenna has increased broad-banding capacities as well as a lower radiation angle for enhanced cellular or mobile telephone wireless transmissions. Enhancing a basic PIFA antenna, a top metal radiator is notched so as to provide additional corners and greater perimeter length thereby enhancing the bandwidth capabilities of the antenna. Both ground and tuning tabs serve to enhance operational characteristics and a dielectric cover incorporating prismatic qualities serves to lower the radiation angle of transmission from approximately forty degrees (40.degree.) to twenty degrees (20.degree.). The prisms provide an operating radiation angle in the range of approximately seventy degrees (70.degree.) to twenty degrees (20.degree.).

Abstract: A small size, flat panel, 1/6.sup.th wavelength antenna is provided. A flat copper-clad dielectric substrate is processed on a first flat side to produce a copper triangular or pseudo triangular-shaped radiating element having a linear copper feed line that extends from the triangle apex. The substrate is also processed on its opposite flat side to produce a rectangular-shaped first copper ground plane element that underlies at least a portion of the copper feed line, but does not underlie the copper radiating element. The first side of the substrate may also be processed to produce a second copper ground plane element that is out of physical engagement with both the copper feed line and the copper radiation element. Aligned through holes are formed in the first ground plane element and the substrate. The metal sheath of a coaxial cable connects to the copper ground plane member(s), and the cable center conductor penetrates the aligned through holes and connects to the copper feed line.

Abstract: An array antenna includes a first ceramic layer and a second ceramic layer. A metal layer is disposed between the first and second ceramic layers. A plurality of radiating elements are mounted on the first ceramic layer, and a plurality of control circuits are mounted on the second ceramic layer. The control circuits are coupled to the radiating elements through a plurality of conductive vias which feed through the metal layer. The array antenna may also include a switch having a plurality of poles formed in the second ceramic layer and coupled to one of the radiating elements through one or more conductive vias. A plurality of phase delay elements may be coupled at a first end to a signal source and coupled at a second end to the respective plurality of poles of the switch to provide phase-delayed signals. A waveguide may also be formed within the ceramic layers. Conductive vias or coaxial transmission lines may be used to connect elements within the array antenna.

Abstract: A wideband antenna element includes a conductive plate parallel to, and spaced from a ground plane. A tapered dielectric material is positioned between the plate and ground plane. A pair of driving points to the plate are positioned fixed distances on either side of a center interconnect point between the plate and ground plane, to effect staggered tuning of the antenna element.

Abstract: An indoor antenna for a UHF and higher frequency receiver has a plurality of polygon shaped conductive elements spaced apart from each other in a three dimensional arrangement. The signals from each pair of elements are combined through adjustable phase and attenuation networks and the combined signal is supplied to the input of a receiver that includes evaluation circuitry for optimizing the response of the antenna system when subjected to multipath conditions. A plurality of sets of random adjustment values are initially applied to the phase and attenuation networks and the antenna response over the signal band is monitored. The set of random values that exhibits the least deviation from the optimum antenna response over the received frequency band is used as the starting point for an optimization program for the calculation of further adjustments to the individual phase and attenuation networks to optimize the antenna response over the received signal band.

Abstract: A dual mode missile seeker system utilizing an infrared transparent radar tenna is disclosed. The infrared transparent radar antenna is mounted in front of and on the same axis as the infrared detector within a missile dome. The radar antenna includes spaced apart patches of infrared transparent semiconductor material and a ground plane of the same material deposited on opposite sides of an infrared and microwave transparent dielectric substrate for transmitting and receiving microwave radiation and for shielding the infrared detector array mounted behind. A radome or separate lens redirects incoming infrared radiation so as to pass through the radar antenna and focus on the infrared detector array.

Abstract: A single-frequency antenna arrangement includes a ground plane, a dielectric substrate, a first antenna contour located on a first side of the dielectric substrate and a second antenna contour located on second side of the dielectric substrate. The first antenna contour and the second antenna contour have substantially the same dimensions in their longitudinal directions and transverse directions. The first antenna contour and the second antenna contour are galvanically interconnected by at least one connection.

Abstract: Of four sides of a quadrilateral conductor to be used as a radiating element, at least three sides are made different in length from each other.

Abstract: A shared antenna in that a linear antenna is electrically connected to the upper end of a power pin of a microstrip plane antenna via a capacitive element. The shared antenna is used in both satellite communications and ground communications and can be used without a need of mechanical switching of the antenna. Further, crimped radiating elements having spatial expansion are electrically connected to the vicinity of the upper end of a feed pin of a microstrip plane antenna via a capacitive element, thereby realizing superior impedance matching and radiation patterns of the shared antenna.

Abstract: The antenna comprises a single rectangular sheet of copper which has been bent firstly to produce a first patch antenna section 1 and secondly to produce a second patch antenna section 3, sections 1 and 3 being joined by and contiguous with section 2. Section 2 is an integral part of the copper sheet and maintains the two sections 1 and 3 in substantially parallel spaced relationship with each other. An air gap 4 exists between sections 1 and 3. Other low absorption insulators may be used in place of air gap 4 and may be selected from a range of such insulators well known in the art. The antenna is backed by a ground plane 6 and is fed by means of a coaxial connector 5 to the distal edge of the larger patch at 7 where excitation of the antenna is effected.

Abstract: A dielectric line has a conductor plate and dielectric strip on the side of a fixed portion and a dielectric line including a conductor plate and dielectric strip on the side of a moving portion. A directional coupler comprises the dielectric lines. On a dielectric plate of an array antenna portion a plurality of linear array antennas are formed and connected to a microstrip as a feed portion. By displacement of the moving portion, the feed point to the feed portion is changed and the feed phase to each linear array antenna and the feed power to each element antenna are changed. Thus, the direction of a beam is changed.

Abstract: An antenna apparatus includes a rectangular conductor plate having a longitudinal length of one fourth the wavelength of a signal having an operating frequency and a line-shaped inverted F antenna mounted thereon. The line-shaped inverted F antenna is disposed at one end in the longitudinal direction of the conductor plate so as to be perpendicular to the longitudinal sides of the conductor plate.

Abstract: A dielectric resonator antenna having a resonator formed from a dielectric material mounted on a ground plane. The ground plane is formed from a conductive material. First and second probes are electrically coupled to the resonator for providing first and second signals, respectively, to or receiving from the resonator. The first and second probes are spaced apart from each other. The first and second probes are formed of conductive strips that are electrically connected to the perimeter of the resonator and are substantially orthogonal with respect to the ground plane. The first and second signals have equal amplitude, but 90 degrees phase difference with respect to each other, to produce a circularly polarized radiation pattern. A dual band antenna can be constructed by positioning and connecting two dielectric resonator antennas together. Each resonator in the dual band configuration resonates at a particular frequency, thereby providing dual band operation.

Abstract: The present invention relates to an antenna array adapted to radiate or receive electromagnetic waves of one or two polarizations with very low cross polarization and low sidelobes. An antenna array comprising many antenna elements, e.g., more than ten antenna elements, is provided in which formation of grating lobes are inhibited in selected directions of the radiation and cross polarization within the main lobe is suppressed at least 30 dB below the main lobe peak value. According to a preferred embodiment of the invention, the antenna elements of the antenna array comprise probe-fed patches, preferably rectangular patches, more preferred, square patches. Further, it is preferred that the feed probes are positioned at the axis of symmetry of the square or rectangular patches.

Abstract: The invention provides An antenna device, comprising: a substrate made of an insulation material and including a first major surface and a second major surface face; a ground electrode provided substantially on the whole of the first major surface of said substrate; and an inverted F-shape antenna and a microstrip antenna respectively provided on the surface of the substrate. An open end of a radiation electrode of the microstrip antenna and a feeding electrode of the inverted F-shape antenna are capacitively coupled to each other. A first direction through the open end and ground end of the radiation electrode of the inverted F-shape antenna is substantially perpendicular to a second direction through the open end and ground end of the radiation electrode of the microstrip antenna. By the above arrangement, a mutual interference hardly occurs between the two antennas.

Abstract: A low cost base station antenna for preventing insertion loss. In the antenna, a printed circuit board (PCB) has a power divider pattern including power divider terminals disposed on one side of the PCB. A conducting ground plate has therein rectangular apertures disposed in line as radiation elements respectively and electromagnetically coupled with each of the power divider terminals of the PCB and disposed to be separated from the PCB by a foamed dielectric sheet with a predetermined thickness so as to be insulated with respect to the power divider pattern. The power divider terminals of the PCB are disposed to terminate within the contour of the apertures and all the power divider terminals are disposed in one line and have a length being a quarter of wavelength. A cavity has a rectangular box with one side open and connected by its open side and by its edges to the ground plate so that all the apertures are disposed within contour of the capacity.

Abstract: A microstrip feeds a patch antenna through a slot in a two part RF ground plane. The dual RF ground planes permit DC control of a varactor positioned over a slot in the ground planes while maintaining a high degree of AC coupling between the two planes. The AC coupling between the two ground planes is increased by increasing the capacitive coupling between the planes using an interlocking finger pattern.

Abstract: A patch antenna having enhanced frequency response has a generally planar element formed of a substantially conductive material, and antenna feed conductor electrically connected to the antenna element, and a generally planar parasitic element formed of a substantially conductive material positioned substantially coaxially with respect to the antenna element and spaced apart therefrom. The distance by which the parasitic element is spaced apart from the antenna element in order to provide such enhanced frequency response of the patch antenna is determined empirically. An optimally configured array of such patch antennas is also disclosed.

Abstract: The invention relates to small-sized antenna systems, especially planar antenna structures operating on several frequency bands. The antenna structure of the invention comprises a radiating antenna element with at least two lips. Thus, the antenna structure has two basic resonance frequencies, which are defined by the dimensions of the lips of the antenna element, gaps between them, and the other dimensions of the antenna structure. The radiating antenna structure is connected to the ground plane at least at one place. The radiating antenna element comprises at least two connection points, which are used for connecting the feed lines of the transmitter and receiver, and for connecting special tuning elements. The resonance frequencies of the antenna structure may be adjusted by connecting the said tuning elements to the connection points and antenna feed lines so that the antenna structure is operable on more than two frequency bands.

Abstract: A surface mount circularly polarized wave antenna which includes a substrate made of an insulating material and having a first main face, a second main face, and at least one side face extending between the first main face and second main face; a first ground electrode disposed on the first main face of the substrate; a radiation electrode disposed on the second main face; a feeding electrode having a strip shape and extending from the first main face of the substrate, on the one side face of the substrate, and toward the second main face, one edge of the feeding electrode being positioned near to one side of the radiation electrode; and a second ground electrode disposed on the one side face of the substrate where the feeding electrode is disposed, and electrically conductively isolated from the feeding electrode and electrically conductively connected to the first ground electrode; and a degeneracy separation element provided in relation to the radiation electrode for causing radiation of a circularly polar

Abstract: A multiband radio antenna arrangement for use in two way radio communication for (UHF) and (SHF) frequencies. The antenna arrangement contains at least one emitter antenna mounted on the outside of the motor vehicle adjacent to an upper edge of the vehicle's windshield near its roof. Supporting the emitter antenna is a base plate secured adjacent to the roof of the vehicle, the baseplate being electrically conductive and serving as the electrical ground plane for the emitter antenna. A thin antenna line feeds into the antenna and extends from a connection point on the baseplate to the upper edge of the windshield where it is bent and then extended on the inside surface of the windshield through an adhesive bead of the window and into the interior of the vehicle. In addition, connected to the baseplate is a patch antenna connected to the antenna line, the patch antenna for receiving an additional radio communication service.

Abstract: An isolation improvement circuit for a dual-polarization antenna, the dual-polarization antenna consisting of both a transmitter and receiver antenna for simultaneously transmitting a transmission signal and receiving a receiver signal, in which the transmitter and receiver antennas are configured so as to be mutually orthogonal either by physical or electrical orientation in order to reduce how much of the transmitter signal is picked up by the receiver antenna. The isolation improvement circuit reduces the level of transmitter signal appearing at the output port of the receiver antenna by providing a time-delayed transmission signal that destructively interferes with the transmitter signal picked up by the receiver element.

Abstract: A method of producing an antenna element assembly is disclosed. The antenna element assembly (4) includes a rigid dielectric support member (1) carrying at least one radiating patch (2), the antenna element assembly being intended to be mounted onto an antenna device for transmitting and/or receiving microwave radiation. According to the invention, parasitic elements (3a, 3b) as well as the radiating patches (2) are formed onto the rigid support member by applying a conductive liquid in a screen printing process.

Abstract: A multibeam radar system includes a multibeam radar module having n (n is a natural number of at least 3) transmitting/receiving channels for transmitting high-frequency signals and receiving echo signals, and a radar circuit for detecting a distance up to an object which produces the echo signals and/or a relative speed of the object from a relationship between the high-frequency signals and the echo signals in the transmitting/receiving channels. The radar circuit includes a channel controller for selecting sets of m (m is a natural number smaller than n) adjacent transmitting/receiving channels sequentially to transmit the high-frequency signals and receive the echo signals in a high-azimuth-resolution mode. The channel controller may also select the transmitting/receiving channels sequentially one by one to transmit the high-frequency signals and receive the echo signals in a low-azimuth-resolution mode.

Abstract: Disclosed is a broadband, miniaturized, slow-wave antenna for transmitting and receiving radio frequency (RF) signals. The slow-wave antenna comprises a dielectric substrate with a traveling wave structure mounted on one surface, and a conductive surface member mounted on the opposite surface. The traveling wave structure, for example, is of the broadband planar type such as various types of spirals and includes conductive arms which are coupled to feed lines which are routed through the dielectric substrate and the conductive surface member for connection to a transmitter or receiver. The dielectric substrate is of a predetermined thickness which is, for example, less than 0.04.lambda..sub.1, where .lambda..sub.1 is the free space wavelength of the lowest frequency f.sub.1 of the operating frequency range of the slow-wave antenna.

Abstract: A multifrequency microstrip antenna in accordance with the present invention includes two zones connected to a short-circuit consisting of two conductive strips. These zones are sufficiently decoupled from each other to enable two resonances to be established in two respective different areas formed by the zones. The resonances are at least approximately of the quarter-wave type and each has an electric field node fixed by the short-circuit. The same coupling device is used to excite the two resonances. The invention applies in particular to portable telephones and to their base stations.

Abstract: A device for microstrip distribution networks and for group antennas for the suppression of unwanted modes on the distribution network side of a microstrip distribution network. This thereby avoids, among other things, unwanted coupling between antenna elements connected to the microstrip distribution network. A waveguide substructure in principle designed as a U of extruded aluminium, is connected to the microstrip distribution network along two connection lines with at least two electrically-conductive connections to the ground plane of the microstrip distribution network along each connection line. Together with at least part of the ground plane, the waveguide substructure forms a waveguide structure. The waveguide structure is dimensioned so that it has a cut-off frequency that is higher than the highest frequency that is used in the microstrip distribution network.

Abstract: A surface mount antenna having a substrate made of at least one of a dielectric material and a magnetic material, the substrate having a substantially rectangular prism shape and including a first major surface and a second major surface; a ground electrode disposed on the first major surface of the substrate; a radiation electrode having a strip shape disposed at least on the second major surface of the substrate; a feeding electrode disposed on at least one surface of the substrate; and the radiation electrode including an open end portion and a plurality of grounded end portions, the open end portion being arranged close to the feeding electrode with a gap therebetween on the substrate, and the plurality of the grounded end portions being connected to the ground electrode on different portions of the substrate, respectively. The above described antenna has an enhanced gain without changes in size.

Abstract: A microstrip antenna has two dielectric layers bonded together with an array of conducting strips interposed therebetween, the strips being spaced to define a slot between each pair of adjacent strips. A conductive ground plane is disposed on a first outer side of the two bonded dielectric layers, and an array of radiating patches are disposed on a second outer side of the two bonded dielectric layers, each of which patches is positioned over a corresponding slot, the array of patches being spaced apart to form an aperture between each pair of adjacent patches. Responsive to electromagnetic energy, a high-order standing wave is induced in the antenna and a directed beam is transmitted from and/or received into the antenna.

Abstract: The present invention provides wireless communication and identification packages, communication systems, methods of identifying an identification device, methods of communicating, and methods of forming a communication device. In one aspect of the present invention, a wireless communication package includes a communication device having a substrate; communication circuitry borne by the substrate, the communication circuitry being configured to at least one of process and form wireless communication signals; and at least one antenna electrically coupled with the communication circuitry, the antenna being configured to at least one of receive wireless communication signals and output wireless communication signals; and an appendage coupled with the communication device, the appendage being configured to enhance at least one of receiving and outputting of wireless communication signals via the antenna.

Abstract: A microstrip antenna includes a composite short-circuit consisting of two conductive strips. A vertical strip, in the plane of the short-circuit between the two strips, is connected to the central conductor of a coupling line forming part of the antenna and enabling the coupling with a resonance thereof, as for example to excite such resonance. The short-circuit and the vertical strip constitute two terminals for said antenna, enabling it to be easily connected to a signal processing units, such as a transmitter. The antenna described includes two zones enabling it to operate at two frequencies. The antenna has particular utility in portable telephones and their base stations.

Abstract: An antenna array is disclosed wherein radiators are parasitically coupled to each other, forming an efficient feed network. Parasitic coupling of patches is arranged so that some patches are fed by a plurality of other patches which are parasitically coupled thereto. The resulting array is low profile and high gain. By positioning patches on different layers with different dimensions, a broadband design for the antenna array is achieved.

Abstract: An antenna is formed from a single sheet of generally planar metal that is cut to provide four geometric antenna shapes that comprise a ground plane element, a two-section shorting element that is defined by two generally parallel fold lines, a radiating element, and an arm that has one end fixed to a generally central portion of the radiating element and has a free end that extends toward a fold line. Folding the metal sheet on the two fold lines positions the radiating element above the ground plane element. A transmit/receive coaxial cable is aligned with a gap that is formed between the two sections of the shorting element. The cable's outer metal sheath is connected to a metal tab, and the metal tab is secured to a surface of the ground plane element. The cable's center conductor is secured to a surface of the radiating element. A radome and its mounting tab complete the antenna assembly.

Abstract: The present invention concerns an integrated circuit structure (1) formed in a substrate (2) and including at least one integrated circuit element (3, 4), an antenna coil (5) capable of transmitting and/or receiving data, and associated with said integrated circuit element(s) (3, 4); and a metal protective ring (20) situated at the periphery of the integrated circuit structure (1). The present invention is characterised in that said protective ring (20) comprises at least one ohmic interruption, so that it does not form a closed circuit on itself. The integrated circuit structure (1) according to the invention is improved in that the operation of the antenna coil (5) is made insensitive to the presence of the protective ring (20).

Abstract: A microstrip patch antenna having reduced size is implementing by providing a substrate having on one surface a conductive fractal pattern, and having on the other surface a conductive pattern that may (but need not) also be a fractal pattern. The fractal pattern is of order N.gtoreq.1, and if fractal patterns are formed on each substrate surface, the fractal family and fractal iteration number may be different. So fractalizing at least one conductive surface permits reduction of substrate dimension may be reduced to one-eighth wavelength.

Abstract: A single dielectric substrate having formed thereon a plurality of planar antenna elements, and a ferrite substrate provided with a circulator are joined together to form a planar antenna module of an integral construction. The planar antenna elements are each composed of a patch formed by a thick or a thin film deposition technique. In one preferred form of joining, the dielectric substrate and the ferrite substrate are joined together at one side. In another preferred form of the joining, the ferrite substrate is fitted or assembled in an opening or window formed in the dielectric substrate.