Abstract: There is disclosed a linear polarization to circular polarization converter. An outside surface of an inner conductor may be coaxial with the inside surface of an outer conductor. First and second diametrically opposed fins may extend outward from the outer surface of the inner conductor. Each of the first and second fins may include a conductive fin and a dielectric fin.

Abstract: This high-frequency waveguide is formed by first and second conductors (22, 23) disposed opposite each other at a spacing of ?0/2, where ?0 is the free space wavelength of the operating frequency of a high-frequency signal. A ridge (25) is provided at the waveguide formation portion between these first and second conductors (22, 23), which protrudes from one of the first and second conductors (22, 23) toward the other and is formed extending along the waveguide formation portion. A plurality of columnar protrusions (24) with a height of ?0/4 are disposed at a spacing of less than ?0/2 to at least one of the first and second conductors (22, 23) on the outside of the waveguide formation portion and to the outside of the ridge (25).

Abstract: There is disclosed a feed network including a circular common waveguide having an axis and terminating in a common port and a first port for coupling a first linearly polarized mode to the circular common waveguide. A phase shifting element may be disposed within the circular waveguide. The phase shifting element may be adapted to cause a predetermined phase shift between a first signal and a second signal propagating in the common waveguide. The phase shifting element may be rotatable about the axis of the common waveguide.

Abstract: There is provided a comb polarizer suitable for millimeter band applications including: a waveguide having an aperture side formed of two separable half waveguides, and a comb shaped conductive unit having a plurality of cogs interposed between two half waveguides for transforming a linear polarized signal to a circular polarized signal.

Abstract: Analyzing a device under test (“DUT”) at higher frequencies. A phase shifter varies the phase of a standing wave on a transmission line coupled to the DUT. The standing wave magnitude is sampled at each of the phase shifts and one or more DUT characteristics are determined as a function of the sampled magnitudes and phase shifts. Further aspects include a related phase shifter comprising a waveguide having a plurality of sub-resonant slots formed therein and having active elements for loading the slots to control the phase shift applied to the signal.

Abstract: A method of changing phase of a microwave electromagnetic beam in free space is provided wherein a cascade of device layers is located transverse to a path of the microwave beam. Each of the device layers have one or more columns. Each column has a device combination series-coupled to an adjacent device combination in the column. Each device combination has a first device having inductive characteristics at microwave frequencies and a second device series-coupled to the first device. The second device has at microwave frequencies characteristics of a fixed capacitance in parallel with a variable capacitance. The capacitance of one or more of the second devices is variable to establish a desired phase shift and a desired frequency band edge within a desired frequency pass band.

Abstract: An adjustable assembly apparatus includes a waveguide phase shifter and a waveguide multiplexer. The waveguide phase shifter has a first flange structure and the waveguide multiplexer has a second flange structure. The second flange structure and the first flange structure are embedded, and the polarization directions of the waveguide phase shifter and the waveguide multiplexer are orthogonal. In an embodiment, the first flange structure includes a bulge, the second flange structure includes a recess, and the bulge is embedded in the recess. The polarization directions of the bulge of the waveguide phase shifter and the recess of the waveguide multiplexer differ by 90 degrees.

Abstract: There is disclosed a linear polarization to circular polarization converter. An outside surface of an inner conductor may be coaxial with the inside surface of an outer conductor. First and second diametrically opposed conductive fins may extend outward from the outer surface of the inner conductor. First and second dielectric fins may be interlocked with the first and second conductive fins, respectively.

Abstract: A dual-band stacked electromagnetic band gap (EBG) electronically scanned array (ESA) has a first aperture with a waveguide element spacing of less than ?/2 and a length to provide about 360° of upper frequency phase shift. A second aperture is stacked on the first aperture and has an element spacing of less than ?/2 at a lower frequency and a length such that when summed with the first aperture length about 360° of lower-frequency phase shift is provided. The second aperture comprises metal slats perpendicular to EBG slats to form an equivalent waveguide element with a broadwall dimension to support a TE10 mode at the upper frequency. The second aperture may also comprise metal slats and alternating frequency selective surface (FSS) slats with perpendicular EBG slats lengthening the broadwall at the upper frequency. The EBG slats provide lower-frequency phase shifting in both embodiments.

Abstract: There is disclosed a feed network including a circular common waveguide having an axis and terminating in a common port and a first port for coupling a first linearly polarized mode to the circular common waveguide. A phase shifting element may be disposed within the circular waveguide. The phase shifting element may be adapted to cause a predetermined phase shift between a first signal and a second signal propagating in the common waveguide. The phase shifting element may be rotatable about the axis of the common waveguide.

Abstract: A waveguide structure is described wherein microwaves or radio-frequency waves can be guided in their propagation through channels whose cross-sections contain fractal patterns, with relevant dimensions much smaller than the wavelengths of the guided waves. A finite section of such waveguide can be used as an efficient delay line.

Abstract: A microwave pulse compressor has an elongated, cross-sectionally oversized waveguide resonator for decreasing the attenuation of the resonator, thereby increasing the resonator's QO The increased Q of the resonator guide results in more stored energy and greater output pulse power. The pulse compressor is constructed to suppress high order modes that can be generated in oversized waveguides. The higher order modes are suppressed by any means, including, separately or in combination, the input coupling design, choice of the resonator length, and the design of the output coupling structures. In one alternative aspect of the invention, the switch at the switch-out end of the waveguide resonator is a plasma switch, employing at least one dielectric window positioned in the resonator guide to have minimum effect on the resonator Q. The dielectric window contains a relatively large volume of a switch gas at low pressure within a switching section of the resonator guide at the guide's switch-out end.

Abstract: There are provided a waveguide forming apparatus, a dielectric waveguide forming apparatus, a pin structure and a high frequency circuit that can optimize a circuit portion provided therein and have high versatility. A waveguide is formed by allowing first and second conductive layers (6, 7) to cooperate with a plurality of control pins (2). A variable high frequency circuit forming portion is freely and simply changed by displacing each control pin (2) between a down-status indicated by Z1 and an up-status indicated by Z2.

Abstract: A microwave bandstop filter comprises a waveguide segment of cross-section that presents longitudinal variation of sinusoidal type modulated by an amplitude function that is continuous, the period of said longitudinal variation of sinusoidal type being the Bragg period for the fundamental guided mode at a center frequency of the band to be stopped. A filter assembly comprises a microwave lowpass filter presenting a cutoff frequency and at least one interfering passband at frequencies higher than said cutoff frequency, and at least one bandstop filter as defined above, connected to the output of said lowpass filter, in which the amplitude and the period of said longitudinal variation, and also the length over which it extends are such that they stop said interfering passband of said lowpass filter. An output multiplexer for a multichannel microwave transmitter includes such a filter assembly.

Abstract: The invention relates to a microwave tube comprising an electron gun generating an electron beam in a cylindrical microwave structure of the tube. The microwave structure delivers a microwave at one output. A collector for collecting electrons from the beam comprising at least one electrode that is mechanically coupled to the microwave structure via a dielectric, the mechanical coupling forming a radial waveguide for propagating spurious microwave radiation (Pr) from the tube. In order to attenuate the spurious radiation from the tube, the radial waveguide (Wg) includes at least one quarter-wave microwave trap having, at least at the operating frequency F of the tube, an open circuit for the microwave propagating in said radial waveguide for propagating spurious radiation.

Abstract: Terminating or otherwise preventing communications in a predefined quiet zone by imposing a time delay. In one embodiment an existing call is terminated during a transition between two wireless access points by imposing a time delay on communications through one of the access points. The time delayed signal is interpreted as noise and causes a base station to drop the call if the noise causes the signal strength from the other access point to fall below a threshold. Within a quiet zone, a signal time delay prevents a client device from responding to a base station connection instruction, which causes the base station to believe that the client device is out of range of a quiet zone access point. The time delay may be imposed by an optical fiber spool between the quiet zone access point and the base station, or other delay mechanism. One embodiment is aboard a vessel.

Abstract: A method and apparatus for changing the polarization of an input signal includes propagating a polarized input signal having orthogonal E-field components by at least one surface each having a respective surface impedance and varying at least one of the surface impedances to shift the phase of one of the components independently from the other so that the polarity of said input signal is changed. Bi-directional propagation is achieved by rotating polarity in one direction but not the other.

Abstract: An apparatus comprising a tuning device having at least one control electrode and a ground electrode located over a substrate and an electrically conductive fluid in contact with the control and ground electrodes. The tuning device also has at least one electrical transmission line electrically coupled to the fluid, the transmission line configured to transmit a signal. The fluid is configured to move when a voltage is applied between the ground electrode and the control electrode, the movement of the fluid changing a propagation characteristic of the signal.

Abstract: The invention relates to a tuneable phase shifter and/or attenuator comprising a waveguide having a channel and a piece of photo-responsive material (18) disposed within the waveguide along an internal wall of said channel, a light source disposed outside the waveguide to emit light through an aperture (30) of said internal wall to impinge on at least part of an outside surface of said piece of photo-responsive material (18).

Abstract: A waveguide is disclosed that shifts the phase of the signal passing through it. In one embodiment, the waveguide has an impedance structure on its walls that resonates at a frequency lower than the frequency of the signal passing through the waveguide. This causes the structure to present a capacitive impedance to the signal, increasing its propagation constant and shifting its phase. Another embodiment of the new waveguide has impedance structures on its wall that are voltage controlled to change the frequency at which the impedance structures resonate. The range of frequencies at which the structure can resonate is below the frequency of the signal passing through the waveguide. This allows the waveguide cause a adjust the shift in the phase of its signal. An amplifier array can be included in the waveguides to amplify the signal. A module can be constructed of the new waveguides and placed in the path of a millimeter beam.

Abstract: A waveguide structure including two parallels electrically conducting ground planes (1,2), each of which includes at least one row of spaced apart electrically conducting posts (3). The rows of posts are arranged substantially parallel to one another and the space bounded by the plates and posts defines a guided wave region (4) along which electromagnetic radiation may propagate. The posts are connected to only one of the planes so that there is no physical connection between the two ground planes (1,2). Actuating means may be connected to one or both of the ground planes to cause relative movement there between to thereby alter the electrical response of the waveguide. The direction of the relative movement may such that the distance between the rows of posts (3) is changed and/or the distance between the ground planes (1,2) is changed. Various device may utilize the described waveguide construction, including reconfigurable waveguide filters and antenna structures e.g. slotted waveguide arrays.

Abstract: A microwave component has a cavity including a plurality of geometrically shaped elements therein wherein the shape profile and position of the elements in relation to the cavity act to define the guiding properties of the cavity and therefore to define operational characteristics of the component.

Abstract: A waveguide is disclosed that shifts the phase of the signal passing through it. In one embodiment, the waveguide has an impedance structure on its walls that resonates at a frequency lower than the frequency of the signal passing through the waveguide. This causes the structure to present a capacitive impedance to the signal, increasing its propagation constant and shifting its phase. Another embodiment of the new waveguide has impedance structures on its wall that are voltage controlled to change the frequency at which the impedance structures resonate. The range of frequencies at which the structure can resonate is below the frequency of the signal passing through the waveguide. This allows the waveguide cause a adjust the shift in the phase of its signal. An amplifier array can be included in the waveguides to amplify the signal. A module can be constructed of the new waveguides and placed in the path of a millimeter beam.

Abstract: A phase error adjustment device configured to connect to an end of a waveguide polarizer and correct phase errors that the waveguide polarizer might generate. In accordance with this embodiment, the phase error adjustment device comprises an aperture having a height and a width, and changes in the dimension of the height or width will change the phase error adjustment quantity. In accordance with another embodiment of the invention, the phase error adjustment device comprises a thickness, and changes in the thickness will change the phase error adjustment quantity.

Abstract: A tunable phase shifter includes a waveguide, a finline substrate positioned within the waveguide, a tunable dielectric layer positioned on the finline substrate, a first conductor positioned on the tunable dielectric layer, and a second conductor positioned on the tunable dielectric layer, with the first and second conductors being separated to form a gap. By controlling a voltage applied to the tunable dielectric material, the phase of a signal passing through the waveguide can be controlled.

Abstract: An electronically scanned slotted waveguide antenna radiates an RF signal as a scannable beam. The antenna has radiation waveguides positioned in an array. Radiation slots in the radiation waveguides radiate the scannable beam. A feed waveguide is coupled to the radiation waveguides. The feed waveguide feeds the RF signal to the radiation waveguides through coupling slots. The feed waveguide has sidewalls with tunable electromagnetic crystal (EMXT) structures thereon. The EMXT structures vary the phase of the RF signal in the feed waveguide to scan the radiated beam in one dimension. The radiation waveguides may also have tunable EMXT structures on the sidewalls to vary the phase of the RF signal to scan the radiated beam in a second dimension. The EMXT structures may be discrete EMXT devices or a EMXT material layer covering the feed and radiation waveguide sidewalls.

Abstract: A microwave component has a cavity including a plurality of geometrically shaped elements therein wherein the shape profile and position of the elements in relation to the cavity act to define the guiding properties of the cavity and therefore to define operational characteristics of the component.

Abstract: A slow wave circuit (10, 110) of a traveling wave tube includes a three-dimensional conductive structure (30, 130). A dielectric film (36, 136) coats selected portions of the three-dimensional conductive structure (30, 130). An outer housing (12, 14, 112, 114) surrounds the three-dimensional conductive structure (30, 130) . The outer housing (12, 14, 112, 114) includes interior surfaces that connect with the dielectric film (36, 136). In a method for generating or amplifying microwave energy, a three-dimensional conductive structure is laser micromachined to define a selected generally periodic pattern thereon. The conductive structure is arranged inside a generally hollow barrel. An electron beam passes through the generally hollow three-dimensional structure and interacts with the conductive structure and the generally hollow barrel to generate or amplify the microwave energy.

Abstract: A variable phase shifter and a system for the variable phase shifter are provided. The phase shifter includes fixed phase shift elements, active devices for amplifying the outputs of the fixed phase shift elements, a combiner for combining the outputs of the active devices. For controlling the phase of the output signal, a bias controller is provided. The bias controller controls the bias of amplification in the fixed phase shift elements. The active devices may be FET or Bipolar Transistors, and are inductively connected to the ground. The phase shifter can be integrated into a system on chip with a smart antenna front-end system.

Abstract: A wave-guide having at least two connection points. In order to adapt a physical distance between these points to a variable distance between connection points of external equipment, at least one connector (20) is provided having a first connecting member (31) for connection to a connection point (28) of the wave-guide and a second connecting member (33) for connection to a connection point of the external equipment. The connecting members of the connector are laterally displaced such that rotation of the second connecting member (33) about the first one (31) results in a variation of the distance between the second connecting member and another connection point of the wave-guide.

Abstract: Phase shifting plasma electromagnetic waveguides and plasma electromagnetic coaxial waveguides, as well as plasma waveguide horn antennas, each of which can be reconfigurable, durable, stealth, and flexible are disclosed. Optionally, an energy modifying medium to reconfigure the waveguide such that electromagnetic waves of various wavelengths or speeds can be propagated directionally along the path can be used. Similarly, these waveguides may be modified into coaxial configurations.

Abstract: A method for the production of an actuator device and an actuator device. The actuator device comprises a more particularly fluid power driven actuator able to move in a housing and a position detecting means, in the case of which by means of an exciting current from a current source an actuator in a magnetostrictive wave guide a concentric magnetic field may be produced, such wave guide being arranged along a working stroke of the actuator, such magnetic field being able to be so influenced by a position indicating magnet arranged on the actuator that an ultrasonic wave deforming the wave guide is obtained. A measurement means is present for the position of the position indicating magnet on the basis of measurement of the transit time of the ultrasonic wave. The wave guide and a return guide for the reflux of the exciting current to the current source are made available on an assembly stage in a predetermined amount suitable for measurement paths of different length, at which the actuator is assembled.

Abstract: A waveguide is disclosed that shifts the phase of the signal passing through it. In one embodiment, the waveguide has an impedance structure on its walls that resonates at a frequency lower than the frequency of the signal passing through the waveguide. This causes the structure to present a capacitive impedance to the signal, increasing its propagation constant and shifting its phase. Another embodiment of the new waveguide has impedance structures on its wall that are voltage controlled to change the frequency at which the impedance structures resonate. The range of frequencies at which the structure can resonate is below the frequency of the signal passing through the waveguide. This allows the waveguide cause a adjust the shift in the phase of its signal. An amplifier array can be included in the waveguides to amplify the signal. A module can be constructed of the new waveguides and placed in the path of a millimeter beam.

Abstract: An apparatus and method for modulating a phase of optical beam. In one embodiment, an apparatus according to embodiments of the present invention includes a first region of semiconductor material disposed in a second region of semiconductor material. An insulating region is disposed between the first and second regions of semiconductor material defining a plurality of interfaces between the insulating region and the first and second regions of semiconductor material. An angle of incidence between an optical beam and the plurality of interfaces is substantially equal to Brewster's angle. A plurality of charge modulated regions proximate to the plurality of interfaces in the first and second regions of semiconductor are included such that the optical beam directed through the plurality of interfaces and the plurality of charge modulated regions is phase shifted in response to the plurality of charge modulated regions.

Abstract: A coplanar waveguide, which has parallel conductor strips that are arranged on a substrate and have an electrically insulating intermediate space between one another, wherein a material with a high dielectric constant is arranged on the conductor strips, on their side facing away from the substrate. In this way, it is possible to achieve a line section with a relatively small characteristic impedance.

Abstract: The present invention aims at providing a circular waveguide polarizer with high performance and low cost. The circular waveguide polarizer is realized by arranging a plurality of side grooves 12 in a side wall of a circular waveguide 11 along the direction of a pipe axis C1 and by appropriately designing the number, spacing, radial depth, circumferential width, length in the pipe axis direction, and the like. According to this circular waveguide polarizer, disturbance is imparted to a section with a coarse electromagnetic field distribution in a transmission mode to create a phase delay, so that the amount of phase delay does not vary largely with a delicate change in width, depth and length of the side grooves 12. That is, there is little deterioration in characteristics caused by a machining error or the like, and hence it becomes possible to effect mass production and cost reductions.

Abstract: In an ultrawide-band linear-circular polarization converter, in a noncircular waveguide which has negative-phase characteristics in which a phase gradually decreases in accordance with an increase in a frequency over an ultrawide-band frequency range, a dielectric structure which has positive-phase characteristics, in which a phase gradually increases in accordance with an increase in a frequency, having a complementary relationship with the negative-phase characteristics in the ultrawide-band frequency range is provided.

Abstract: Fluidic self-assembly of active antenna. An embodiment that is described in the specification and drawings include a strip of substrate material having an antenna on one side, signal and power busses on the other side, and one or more channel laid out across the strip of substrate material from the antenna to the signal and power busses. The strip of substrate material may have a number of recessed regions and shaped blocks disposed in the recessed regions via a fluidic self-assembly process. The shaped blocks may include micro-switches, CMOS control circuitry, and III-V semiconductor amplifiers. The strip may then be stacked together vertically with spacers to form a two dimensional phased-array.

Abstract: A waveguide is disclosed that shifts the phase of the signal passing through it. In one embodiment, the waveguide has an impedance structure on its walls that resonates at a frequency lower than the frequency of the signal passing through the waveguide. This causes the structure to present a capacitive impedance to the signal, increasing its propagation constant and shifting its phase. Another embodiment of the new waveguide has impedance structures on its wall that are voltage controlled to change the frequency at which the impedance structures resonate. The range of frequencies at which the structure can resonate is below the frequency of the signal passing through the waveguide. This allows the waveguide cause a adjust the shift in the phase of its signal. An amplifier array can be included in the waveguides to amplify the signal. A module can be constructed of the new waveguides and placed in the path of a millimeter beam.

Abstract: A coplanar waveguide for use in dielectric spectroscopy of biological solution is described. The waveguide's inner conductor can have a small gap and a sample containing space is laid over the gap. The sample containing space holds a small volume, ranging from a few picoliters to a few microliters of a biological solution. The waveguide is then driven with electrical signals across an extremely wide frequency range from 40 Hz to 40 GHz. The waveguide is coupled to a network or impedance analyzer by means of appropriate connectors and the response of the biological solution to the input signals is recorded. One-port and two-port measurements can be made without any modifications. The simple geometry of the waveguide makes it easy to integrate with microfluidic systems.

Abstract: This invention relates to the design of a microwave component utilizing geometric shapes positioned within the channel of a waveguide structure so as to produce microwave manipulation characteristics, with associated near and far fields, whereby predetermined performance requirements may be satisfied.

Abstract: Fluidic self-assembly of active antenna. An embodiment that is described in the specification and drawings include a strip of substrate material having an antenna on one side, signal and power busses on the other side, and one or more channel laid out across the strip of substrate material from the antenna to the signal and power busses. The strip of substrate material may have a number of recessed regions and shaped blocks disposed in the recessed regions via a fluidic self-assembly process. The shaped blocks may include micro-switches, CMOS control circuitry, and III-V semiconductor amplifiers. The strip may then be stacked together vertically with spacers to form a two dimensional phased-array.

Abstract: A circular polarizer includes a low frequency band waveguide (fL), a high frequency band waveguide (fH) formed at the inner side of the low frequency band waveguide (fL) in a coaxial structure, and a dielectric member provided to abut against the inner side of the low frequency band waveguide (fL) and the outer side of the high frequency band waveguide (fH), and inclined by 45° with respect to a linear plane of polarization. Since the dielectric member is provided at an angle of 45° with respect to the linear plane of polarization, the delay of the phase of the electric field passing through the dielectric member becomes greater than the phase of the electric field orthogonal to the dielectric member, whereby a circularly polarized wave can be converted into a linearly polarized wave. Since the dielectric member can be formed by a mold, a circular polarizer that is economic and fit for mass production can be provided.

Abstract: A tunable phase shifter includes a waveguide, a finline substrate positioned within the waveguide, a tunable dielectric layer positioned on the finline substrate, a first conductor positioned on the tunable dielectric layer, and a second conductor positioned on the tunable dielectric layer, with the first and second conductors being separated to form a gap. By controlling a voltage applied to the tunable dielectric material, the phase of a signal passing through the waveguide can be controlled.

Abstract: A right circular cylindrical body of an isotropic dielectric such as a cross-linked styrene copolymer, has respective pluralities of mutually parallel grooves formed in its axial end faces, spaced apart by an intermediate portion whose dimension c is a half wavelength. The axial lengths a, b of the grooves are such that when a wave passes through the body, a quarter wavelength phase difference is produced between a component of a wave having its E-vector parallel to the grooves and a component of the wave having its E-vector orthogonal to the grooves. Alternatively the plate may consist of two or more discrete bodies whose grooves are dimensioned to produce a total differential phase shift of one quarter wavelength.

Abstract: For the connection, a transition plate (11), for rotating the polarization of the waves leaving one (2) of the guides into an intermediate transition polarization, which is not parallel to the polarizations of the two guides, is inserted between the two waveguides (1, 2), the plate (11) is fixed to one (2) of the two waveguides and one end of the other waveguide (1) is introduced into a recess (12) for housing the transition plate (11).

Abstract: A reflective waveguide variable power divider/combiner comprises an orthomode tee section, which includes a section of cylindrical waveguide and a rotatable reflective phase shifter section. The rotatable reflective phase shifter section is rotatably connected to the orthomode tee section by a cylindrical choke joint. The orthomode tee section includes a single orthomode tee unit. The reflective waveguide variable power divider/combiner terminates at a short circuit that separates a motor from the rotatable reflective phase shifter section. The motor is configured to rotate the rotatable reflective phase shifter section relative to the orthomode tee section.

Abstract: A broad band waveguide polarizer having four axial ridges, one on each wall of the waveguide, is disclosed. The axial ridges are configured to provide different phase velocities for the orthogonal signal components of a linearly polarized input signal. The dimensions of the ridges are selected such that the net phase difference between the signal components is about 90 degrees at a predetermined signal frequency. The quad ridge polarizer may be manufactured as an integral die cast device.

Abstract: A user terminal (110) which comprises an electrically-controllable back-fed antenna (300, FIG. 3) is used for the formation of single and multiple beams. The electrically-controllable back-fed antenna comprises an RF power distribution/combination network (310), electrically-controllable phase-shifting elements (320), a control network (440, FIG. 4) and radiating/receiving elements (360). The control network is coupled to the electrically-controllable phase-shifting elements and is used for controlling the dielectric constant of dielectric material contained within the electrically-controllable phase-shifting elements. In a preferred embodiment, phase-shifting elements comprise waveguide sections containing at least one dielectric material, and the dielectric material includes a ferroelectric material, preferably comprising Barium Strontium Titanate (BST).

Abstract: An acoustic wave identification transponder device, having a substrate, an electroacoustic transducer generating an acoustic wave in said substrate and a set of encoding elements disposed in a path of the acoustic wave for modifying the acoustic wave, having at least two reflective elements disposed in the acoustic path of the acoustic wave such that an acoustic path length of the acoustic wave on the substrate is longer than twice a largest linear dimension of the substrate. The device preferably includes an angled elongated conductor formed on said substrate, having angle magnitudes whose sum exceeds .pi. radians, said angled elongated conductor defining at least a portion of the acoustic path.