Showing papers on "Insertion loss published in 1993"
TL;DR: In this article, a polymer waveguide thermooptic 2*2 switch with low electric power consumption is demonstrated, which consists of a Mach-Zehnder interferometer with thin-film heaters.
Abstract: A polymer waveguide thermooptic 2*2 switch with low electric power consumption is demonstrated. The switch consists of a Mach-Zehnder interferometer with Cr thin-film heaters. The waveguides are fabricated using acrylic polymers synthesized from deuterated methacrylate and deuterated fluoromethacrylate monomers. The total insertion loss of the switch is 0.6 dB at a wavelength of 1.3 mu m, including fiber coupling losses and waveguide losses. The switching power is as low as 4.8 mW, and the rise and fall times are both 9 ms. >
128 citations
TL;DR: In this article, a single-mode photo-sensitive waveguide Mach-Zehnder interferometer fabricated in Ge-doped planar silica is reported, and two-millimeter-long identical-wavelength reflection gratings using external UV beams have been written into each arm to demonstrate a four-port bandpass device for the first time using this technology.
Abstract: A single-mode photosensitive waveguide Mach-Zehnder interferometer fabricated in Ge-doped planar silica is reported. Two-millimeter-long identical-wavelength reflection gratings using external UV beams have been written into each arm to demonstrate a four-port bandpass device for the first time using this technology. The imbalance in the arms after writing of the gratings is compensated by laser trimming of one photosensitive arm of the interferometer. A 96.8% reflection of the output port is measured, and 58.8% of the total power available at the input at 1.5558 mu m in the bandpass of 1 nm is transmitted at the second input port after laser trimming. The total fiber-to-fiber insertion loss of the device is measured to be 1.35 dB. >
119 citations
TL;DR: In this paper, the authors describe the design and performance of shunt inductively coupled bandpass filters implemented on an open coplanar waveguide, which exhibits low radiation loss due to the removal of the capacitively coupled gaps encountered in end or edge coupled filters.
Abstract: This paper describes the design and performance of shunt inductively coupled bandpass filters implemented on an open coplanar waveguide. This new structure exhibits low radiation loss due to the removal of the capacitively coupled gaps encountered in end or edge coupled filters. Unloaded Qs greater than 540 have been achieved in unshielded single section resonators at 4 GHz on very thin substrates. These high Qs enable the design of filters with low insertion loss and good stopband rejection. Applications include low insertion loss, high and printed filters where no screening is required, low noise oscillators and superconducting filters. >
118 citations
TL;DR: In this paper, a polarisation independent InP-based 8×8 multiplexer is realized by designing the free spectral range to exactly match the TM-TE shift, which exhibits a channel spacing of 88.4 GHz (0.71 nm), a crosstalk of −20 dB and a channel bandwidth of 39 GHz (1.31 nm).
Abstract: A polarisation independent InP-based 8×8 multiplexer is realised by designing the free spectral range to exactly match the TM-TE shift. The device exhibits a channel spacing of 88.4 GHz (0.71 nm), a crosstalk of −20 dB and a channel bandwidth of 39 GHz (0.31 nm). The insertion loss is below 5 dB for all eight channels.
116 citations
TL;DR: In this article, a simple InP/InGaAsP tapered waveguide is proposed for low-loss coupling between semiconductor photonic devices and single-mode fibers.
Abstract: Low-loss coupling between semiconductor photonic devices and single-mode fibers is achieved using a simple InP/InGaAsP tapered waveguide. The proposed simple structure has a small and nearly square guiding core at its output facet. In this structure, the output field has a non-Gaussian profile, but low-pass filter coupling can be achieved by optimizing the design of the guiding core sizes. The waveguide is composed of a laterally tapered InGaAsP guiding layer and an InP cladding region on an InP substrate, facilitating integration of the waveguide with active devices using conventional processes. The waveguide is shown to have a total insertion loss of 2.6 dB, including a coupling loss of 0.9 dB and large +or-2.5- mu m misalignment tolerance in lateral and vertical directions with single-mode filters. >
113 citations
TL;DR: In this paper, a waveguide array multiplexer design that is particularly suitable for making broadband low-order devices is presented, which has a wide spectral range of low crosstalk and fiber-to-fiber insertion loss.
Abstract: A waveguide array multiplexer design that is particularly suitable for making broadband low-order devices is presented. Two-channel multiplexers at 1.0-1.55 mu m, 1.31-1.53 mu m, and 1.47-1.55 mu m are demonstrated. Compared to conventional waveguide multiplexers, these devices have wide spectral ranges of low crosstalk. The devices are polarization independent. The crosstalk and fiber-to-fiber insertion loss for the 1.31-1.53 mu m multiplexer were about -35 and -2 dB, respectively. >
108 citations
TL;DR: In this article, the insertion loss measurement technique and the backcoupling method are suitable for the measurement of attenuation values alpha L>or=1. But they give small relative mean errors of the attenuation only for high finesse resonators, which can, in principle, be realized by a waveguide Fabry-Perot resonator with high reflecting endfaces.
Abstract: Three techniques for the measurement of propagation losses of single mode integrated optical waveguides are compared. The insertion loss measurement technique and the backcoupling method are suitable for the measurement of attenuation values alpha L>or=1. The resonator techniques give small relative mean errors of the attenuation only for high finesse resonators, which can, in principle, be realized by a waveguide Fabry-Perot resonator with high reflecting endfaces. A more convenient solution, however, is an additional ring resonator on the integrated optical chip.
87 citations
14 Jun 1993
TL;DR: In this paper, a novel wideband balun has been developed for MMIC (monolithic microwave integrated circuit) applications using simple RF reflection and coupling principles to achieve a wideband performance in a simple microstrip configuration.
Abstract: A novel wideband balun has been developed for MMIC (monolithic microwave integrated circuit) applications Simple RF reflection and coupling principles are used to achieve a wideband performance in a simple microstrip configuration The design was intended for 8- to 18-GHz wideband mixer applications According to the predicted performance the insertion loss was better than 2 dB from 7 to 19 GHz, the amplitude balance was less than 1 dB, and the phase balance was less than 5 degrees from the 180 degrees phase difference Experimental results show very good agreement with the predicted performance >
85 citations
14 Jun 1993
TL;DR: In this paper, a master-slave filter control circuit with fully integrated RF components was shown to track a reference signal over a frequency range greater than 2.5 GHz while maintaining the slaved filter notch depth at greater than 25 dB over that band.
Abstract: Fully integrated, narrowband, tunable active filter monolithic microwave integrated circuits (MMICs) have been demonstrated at X-band. The three-section bandpass chip had a minimum insertion loss of less than 1.5 dB and a -3 dB bandwidth of 3% at 8.4 GHz. The notch filter chip exhibited a minimum -30 dB notch bandwidth of 20 MHz and a 2.7-GHz tuning range. A master-slave filter control circuit with fully integrated RF components was shown to track a reference signal over a frequency range greater than 2.5 GHz while maintaining the slaved filter notch depth at greater than 25 dB over that band. The same control circuit virtually eliminated the temperature dependence of the notch depth and provided a five-fold reduction in the notch frequency drift. >
62 citations
TL;DR: In this paper, a 15 GHz range low insertion loss surface acoustic wave (SAW) filter has been developed using a ZnO/sapphire substrate and IIDT-type electrodes with two external reflectors.
Abstract: A 15 GHz range low insertion loss surface acoustic wave (SAW) filter has been developed using a ZnO/sapphire substrate and IIDT-type electrodes with two external reflectors This filter had an insertion loss of 13 dB, stop-band attenuation of greater than 30 dB and matching impedance of 50 Ω pure resistivity without external matching networks This filter has the smallest insertion loss of all transverse-type GHz-range SAW filters reported previously and it is suitable for use as a RF-stage filter for future 15 GHz range Japanese digital cellular systems
57 citations
Patent•
29 Mar 1993TL;DR: Polymeric elongated waveguide emulating (PEWE) lens as mentioned in this paper is an integrated optical package including an optical component having an asymmetric modal output, and a lens integrated with the component for coupling to another component having a large modal area.
Abstract: This invention embodies an integrated optical package including an optical component having an asymmetric modal output, and a lens integrated with the component for coupling to another component having a large modal area. The coupling is achieved by the use a tapered waveguide section (12). This section may be referred to as Polymeric Elongated Waveguide Emulating (PEWE) lens. In the exemplary embodiment the first optical component is a modulator (11), and the other optical component is an optical fiber (13). A facet of the modulator is etched by reactive ion etching (RIE) which allows integration of the PEWE lens on a common substrate (14). The lens is manufactured using a polymer film on a dielectric cladding layer. The fabrication relies on the remelt and reflow properties of polymer films to provide a smooth adiabatic mode contraction from a circular (optical fiber) mode (≈6µm in diameter) to a semiconductor mode (≈1µm) over a length of 250 µm. The PEWE lens permits coupling with an insertion loss of 0.5 dB and 80 percent coupling efficiency, even though the lens is butt-coupled to a fiber without any external lens. The PEWE lens allows the realization of better than 80 percent direct fiber butt-coupling efficiencies to semiconductor lasers, photodetectors, optical modulators, switches and amplifiers with a simultaneous order of magnitude relaxation of the alignment tolerances typically needed for the coupling of semiconductor devices with single-mode fibers.
TL;DR: In this paper, a large-core multimode passive waveguide with a thin buried active layer is designed to yield a high coupling efficiency to conventional single-mode fibers, and the quantum well material structure is optimized to maximize Delta alpha/Delta F/sup 2, where Delta alpha is the absorption change, alpha /sub 0/ is the residual absorption at zero bias, and Delta F is the swing of the applied electric field.
Abstract: Optical on-off modulators require low insertion loss, high contrast ratio (CR), small drive power and large bandwidth or bit-rate. A systematic approach to optimize the total performance of these modulators based on the quantum-confined Stark effect is presented here. The approach consists of minimizing the power/bandwidth ratio while satisfying a given CR and insertion loss. Our design consists of a large-core multimode passive waveguide with a thin buried active layer. The passive waveguide is designed to yield a high coupling efficiency to conventional single-mode fibers. The quantum well material structure is designed to maximize Delta alpha / Delta F/sup 2/, while maintaining a sufficiently large Delta alpha / alpha /sub 0/, where Delta alpha is the absorption change, alpha /sub 0/ is the residual absorption at zero bias, and Delta F is the swing of the applied electric field. Our theoretical model shows that i) wider quantum wells give larger Delta alpha / Delta F/sup 2/, and ii) the bandwidth/power ratio as high as 4 GHz/mW can be achieved simultaneously with small insertion loss, For example, with a drive voltage of 3 V, an RC limited bandwidth as high as 60 GHz is predicted, while a contrast ratio of 20 dB and a total insertion loss of 4.5 dB may also be obtained. >
14 Jun 1993
TL;DR: The authors describe a fiber-optic link architecture which minimizes noise figure by combining the two complementary outputs of a Y-fed coupler electrooptic modulator in such a way that the optical noise cancels in a balanced receiver module.
Abstract: The authors describe a fiber-optic link architecture which minimizes noise figure by combining the two complementary outputs of a Y-fed coupler electrooptic modulator in such a way that the optical noise cancels in a balanced receiver module. The demonstration link exhibits 9.5-dB insertion loss and 13.5-dB noise figure at 900 MHz. >
TL;DR: In this article, a monolithic integration of p-i-n diode switch, variable gain control, and attenuation functions in an HBT technology without additional processing steps or MBE material growth is presented.
Abstract: The authors report on monolithic circuits integrating HBTs and p-i-n diode using a common HBT MBE structure. An HBT variable gain amplifier using p-i-n diode as a variable resistor achieved a gain of 14.6 dB, a bandwidth out to 9 GHz, a gain control range of >15 dB, and an IP3 of 28 dBm. A two-stage HBT p-i-n diode attenuator from 1-10 GHz and an X-band one-pole two-throw HBT p-i-n diode switch were also demonstrated. The two-stage p-i-n attenuator has over 50 dB dynamic range at 2 GHz and a maximum IP3 of 9 dBm. The minimum insertion loss is 1.7 dB per stage and has a flat response to 10 GHz. The X-band switch has an insertion loss of 0.82 dB and an off-isolation of 25 dB. The bandwidth is greater than 35% and the IP3 is greater than 34.5 dBm. These circuits consist of p-i-n diodes constructed from the base-collector MBE layers of a baseline HBT process. This is the first monolithic integration of p-i-n diode switch, variable gain control, and attenuation functions in an HBT technology without additional processing steps or MBE material growth. >
TL;DR: In this article, slotline and CPW ring resonators are introduced and integrated with varactor diodes to create electronically tunable uniplanar ring Resonators, which offer the ground plane and center conductor on the same side of the substrate to allow easy series or shunt insertion of solid state devices.
Abstract: Slotline and CPW ring resonators are introduced and integrated with varactor diodes to create electronically tunable uniplanar ring resonators. Varactors electronically tune the second resonant mode of the slotline ring over a 23% bandwidth from 3.03 to 3.83 GHz with a 4.5+or-1.5 dB variation in insertion loss. Similarly, a CPW ring resonator was tuned over a 22% bandwidth from 2.88 to 3.59 GHz. Both resonators offer the ground plane and center conductor on the same side of the substrate to allow easy series or shunt insertion of solid-state devices. DC biasing is naturally integrated in the slotline structure and straightforward in CPW. Monolithic implementation of these resonators would not require via holes to ground solid-state devices which should reduce processing complexity and increase production yields. >
Patent•
09 Mar 1993
TL;DR: In this article, the authors proposed to realize a small loss and a large extent of out-band attenuation by constituting a surface acoustic wave filter of an one-post acoustic wave resonator and a surface two-ports acoustic wave Resonator.
Abstract: PURPOSE: To realize a small loss and a large extent of out-band attenuation by constituting a surface acoustic wave filter of an one-post surface acoustic wave resonator and a surface two-ports acoustic wave resonator CONSTITUTION: A surface acoustic wave resonator 4 to one terminal has such impedance characteristic that the impedance is 0 in the case of a resonance frequency fr and is infinite in the case of an antiresonance frequency fa Consequently, the electric signal from an input terminal 6 passes an output terminal 7 in the case of the frequency fr but does not pass it at all in the case of the frequency fa to generate an attenuation pole when resonators 4 are connected in series to constitute a circuit to two terminals Meanwhile, a surface acoustic wave resonator 5 to two terminals generates a spurious wave in a high band-side vicinity fs of the pass band However, the spurious wave of the resonator 5 is cancelled by the attenuaLion pole of the resonator 4 to increase the extent of out-band attenuation because resonators 4 and 5 are cascade connected and are so constituted that frequencies fa and fs are equal to each other Further, the pass band of the resonator 5 is equalized to the frequency fr of the resonator 4 to reduce the insertion loss in comparison with multistage connection of resonators 5 COPYRIGHT: (C)1994,JPO&Japio
14 Jun 1993
TL;DR: In this article, a W-band probe based on a coaxial line design has been developed, with built-in bias tee, 2-dB insertion loss and better than 12-dB return loss from 75 GHz to 110 GHz.
Abstract: A W-band wafer probe based on a coaxial line design has been developed. With built-in bias tee, 2-dB insertion loss and better than 12-dB return loss from 75 GHz to 110 GHz are achieved. A probe without bias tee has 1.3-dB loss and 1.5-dB return loss at 94 GHz when optimized for narrowband application. S-parameters of discrete transistors and circuits have been accurately measured from 75 GHz to 110 GHz. The noise figure of active circuits has also been measured at W-band with these probes. >
TL;DR: In this paper, the semiconductor bulk acoustic resonator (SBAR) is fabricated on gallium arsenide (GaAs) wafers by depositing the thin film layers on top of the wafer and then etching away the GaAs from below, leaving a thin membrane supported by its edges.
Abstract: The semiconductor bulk acoustic resonator (SBAR) is composed entirely of thin films, namely, piezoelectric aluminum nitride (AlN) and metal electrode films (primarily aluminum). It is fabricated on gallium arsenide (GaAs) wafers by depositing the thin film layers on top of the wafer and then etching away the GaAs from below, leaving a thin membrane supported by its edges. SBAR resonators and filters can be fabricated as part of the heterojunction bipolar transistors (HBT) or metal-semiconductor FET (MESFET) monolithic microwave integrated circuit (MMIC) processes, offering the high selectivity associated with acoustic resonators and filters to the MMIC designer. Performance of recent one-pole SBAR filter which has only 6.1-dB insertion loss at 7.8 GHz (second harmonic) and 7.5-dB insertion loss at 11.6 GHz (third harmonic), with fractional bandwidths less than 1% is described. Also described are two-pole (1.4% bandwidth) and four-pole (1.8% bandwidth) Chebyshev monolithic SBAR filters at 2.4 GHz, demonstrating flat passbands and good rejection. These results demonstrate that SBAR technology is practical for monolithic filters in MMICs at frequencies up to X-band. >
TL;DR: In this paper, a superconducting delay line with 27 and 44-ns delay on thinned LaAlO/sub 3/ and sapphire substrates is presented.
Abstract: The very low microwave surface resistance of high-temperature-superconductor (HTS) thin films allows the realization of microwave devices with performance superior to those made by conventional technology. Superconducting delay lines, for example, have very low propagation loss and dispersion. Long, low-loss, superconducting delay lines on both thinned LaAlO/sub 3/ and sapphire substrates are presented. Delay lines with 27- and 44-ns delay have been made, for the first time, on 5-cm-diameter 254- and 127- mu m-thick LaAlO/sub 3/ substrates, respectively. The insertion losses at 77 K and 6 GHz are 6 and 16 dB, respectively. Delay lines with 9-ns delay have, for the first time, been produced on M-plane sapphire substrates and demonstrate, at 77 K, an insertion loss of 1.0 dB at 6 GHz. A 2.5%-bandwidth 10 GHz four pole edge-coupled bandpass filter on M-plane sapphire substrates is also reported. The filter has minimum insertion loss of less than 0.5 dB at 9.75 GHz and 71 K. >
TL;DR: In this paper, simple design formulas for optical power splitters with an arbitrary number of output ports (1*N) are presented using a model based on the interference of the confined modes of a multimode wide section.
Abstract: Simple design formulas for optical power splitters with an arbitrary number of output ports (1*N) are presented. They are obtained using a model based on the interference of the confined modes of a multimode wide section. These formulas provide the correct dimensions of the device, plus the output phase relations and output guides location. The accuracy of these formulas is further demonstrated by the design and fabrication of a buried heterostructure waveguide power splitter on InP, compatible with laser integration, that yield compact and low insertion losses devices. >
TL;DR: In this paper, modified broadside-coupled microstrip lines, suitable for microwave and millimeter-wave integrated and monolithic integrated circuit (MIC and MMIC) applications requiring wide bandwidths and tight couplings, are presented.
Abstract: Modified broadside-coupled microstrip lines, suitable for microwave and millimeter-wave integrated and monolithic integrated circuit (MIC and MMIC) applications requiring wide bandwidths and tight couplings, are presented. Their analysis, based on the quasi-static spectral domain technique, is described. Using these broadside structures, a new class of broadside-coupled band-pass filters has been developed at X-band (8-12 GHz) with about 1-dB insertion loss. Fair agreement between the measured and calculated results has been observed even though a major approximation is used. >
TL;DR: In this article, a ZnO/diamond system was used to generate surface acoustic wave (SAW) devices for passive component applications, and a 1.07 GHz bandpass filter was successfully demonstrated using 2 μm line and space interdigital transducers; additionally −25 dB insertion loss was observed.
10 Oct 1993
TL;DR: In this paper, GaAs MESFET switch ICs operating at low control voltages of 0V/-3V and +3V/0V have been developed for use in the personal handy phone using 1.9 GHz band.
Abstract: GaAs MESFET switch ICs operating at low control voltages of 0V/-3V and +3V/0V have been developed for use in the personal handy phone using 1.9 GHz band. The switch ICs have excellent RF characteristics, and have no need for external circuit installation. The unique points of these ICs are the use of GaAs MESFETs with two kinds of pinch-off voltages and a symmetrical source and drain pattern configuration with respect to the gate. The 0V/-3V IC had a low insertion loss of 0.55 dB and 0.65 dB, and high isolation of 31 dB and 24 dB at receiving and transmitting operation, respectively. The +3V/0V IC also had excellent characteristics such as insertion loss of 0.73 dB and 0.95 dB, and isolation of 27 dB and 23 dB, respectively. Both ICs had an output power at 1 dB gain compression point of 25.4 dBm and third-order intercept point of more than 46 dBm. >
14 Jun 1993
TL;DR: In this article, the design and measured performance of GaAs MMIC linearizers for use with spaceborne traveling wave tube amplifiers (TWTAs) are presented, and are based on a passive FET design similar to that of MMIC switches and attenuators.
Abstract: The design and measured performance of GaAs MMIC (monolithic microwave integrated circuits) linearizers for use with spaceborne traveling wave tube amplifiers (TWTAs) are presented. These linearizers operate at C, X, and Ku-band, and are based on a passive FET design similar to that of MMIC switches and attenuators. MESFET varactors and voltage variable resistors are used as control elements. More than 2.5 GHz of bandwidth is obtained at Ku-band with an improvement of greater than 10 dB in TWTA carrier-to-intermodulation ratio (C/I), and a phase change of less than 5 degrees . Linearizer insertion loss was reduced to below 8 dB at C-band and 10 dB at Ku-band. The MMICs also verified the soundness of the CAD (computer-aided design) modeling techniques used to develop the chips, and the value of the unique MMIC air bridge over metal tuning technique incorporated into the designs. >
Patent•
01 Nov 1993
TL;DR: In this article, an improved multiplexer comprises a housing, a transmission line transformer section within the housing extending in a first direction, and at least two interdigital transmission line filters adjacently disposed within a housing along the first direction.
Abstract: An improved multiplexer comprises a housing, a transmission line transformer section within the housing extending in a first direction, and at least two interdigital transmission line filters adjacently disposed within the housing along the first direction The transformer section has a first end electrically coupled to an antenna circuit connector, and a second end electrically coupled to the housing (ie grounded) Each filter includes several resonating elements At least one resonating element of each filter is located in proximity with a portion of the transformer such that electrical coupling between the filter and the transformer is established The length of each coupling portion of the transformer is approximately one-quarter electrical wavelength at the center frequency of the associated filter The dimensions of the filter cavities are preferably selected to be as small as possible without unacceptably degrading the filter insertion loss Further, the filters, and the associated coupling portions of the transformer, are disposed in close proximity The filter cavity size and spacing are such that the transformer coupling portions of adjacent filters are no more than about one-eighth wavelength apart (measured along the first direction) This provides a significant reduction in the physical volume required for prior art multiplexers employing interdigital filters An adjustable-frequency resonating element formed as a longitudinally extending body portion having an deformable leaf adjustment member at one end Deformation of the adjustment member modifies the effective electrical length, and thereby, the resonant frequency, of the resonator
TL;DR: A waveguide polarizer using an ARROW (antiresonant reflecting optical waveguide) structure, of which the first cladding consists of three thin layers, is proposed in this paper.
Abstract: A waveguide polarizer using an ARROW (antiresonant reflecting optical waveguide) structure, of which the first cladding consists of three thin layers, is proposed. Theoretical calculation shows that this polarizer can achieve isolation over 30 dB/cm with an insertion loss of 0.01 dB/cm at 1.3 mu m. Isolation of 83 dB/cm with insertion loss of 4.3 dB/cm was experimentally obtained at 0.633 mu m. This structure is suitable for the integration of a polarization splitter and photodetector. >
Patent•
17 Aug 1993TL;DR: In this article, a polymeric elongated waveguide emulating (PEWE) lens was used for coupling optical modulators with a semiconductor modulator, achieving better than 80 percent direct fiber butt-coupling efficiency.
Abstract: This invention embodies an integrated optical package including an optical component having an asymmetric modal output, and a lens integrated with the component for coupling to another optical component having a large modal area. The coupling is achieved by the use of a Polymeric Elongated Waveguide Emulating (PEWE) lens. In the exemplary embodiment the first optical component is a modulator, and the other optical component is an optical fiber. A facet of the modulator is etched by reactive ion etching (REE) which allows integration of the PEWE lens on a common substrate. The lens is manufactured using a polymer film on a dielectric cladding layer. The fabrication relies on the remelt and reflow properties of polymer films to provide a smooth adiabatic mode contraction from a circular (optical fiber) mode (≈6 μm in diameter) to a semiconductor mode (≈1 μm) over a length of 250 μm. The PEWE lens permits coupling with an insertion loss of 0.5 dB and 80 percent-coupling efficiency, even though the lens is butt-coupled to a fiber without any external lens. The PEWE lens allows the realization of better than 80 percent direct fiber butt-coupling efficiencies to semiconductor lasers, photodetectors, optical modulators, switches and amplifiers with a simultaneous order of magnitude relaxation of the alignment tolerances typically needed for the coupling of semiconductor devices with single-mode fibers.
31 Oct 1993
TL;DR: In this article, a 1.5 GHz bandpass filter was demonstrated using a 15 mm thick poly-crystalline diamond deposited on a silicon substrate by hot-filament CVD was used as a substrate.
Abstract: Due to its high Young modulus, diamond has the highest acoustic wave velocity among all materials and thus it can be expected to be a candidate of the substrate for high frequency surface acoustic wave (SAW) devices. 15 mm thick poly-crystalline diamond deposited on a silicon substrate by hot-filament CVD was used as a substrate. For the piezoelectric material, ZnO film was deposited by RF sputtering. A 1.5 GHz bandpass filter was successfully demonstrated using a 1.5 mm line and space single electrode; additionally a 12.1 dB insertion loss including a 6 dB bi-directional loss was observed. The phase velocity of 8900 m/s and an electro-mechanical coupling constant of 1.76% were obtained for this filter. The propagation loss of this structure was estimated to be 3.9 dB- most of this is presumably losses in ZnO. This loss can be reduced by process refinement of ZnO deposition
TL;DR: In this article, a simple model of diffraction is developed that can predict accurately the insertion loss of finite length barriers, which is based on the geometric theory of minimum diffracted paths, and it provides a clear picture of the sound attenuation performance of a barrier as a function of barrier length.
Abstract: A simple model of diffraction is developed that can predict accurately the insertion loss of finite length barriers. The model is based on the geometric theory of minimum diffracted paths. Assumptions are made on the phase and amplitude of each diffracted wave to obtain a new and rather simple formulation of the solution. It provides a clear picture of the sound attenuation performance of a barrier as a function of barrier length. Extensive model experiments are used to verify the model. The model’s accuracy in predicting the overall pattern of the narrow‐band insertion loss is found to be comparable to that of an integral equation method, although the latter method produces better prediction in the fine details of the sound field. The model is much simpler than and as accurate as other methods that apply the usual geometric solutions to each diffracted path, and represents a major improvement on Maekawa’s energy summation method for octave band finite barrier calculations.