scispace - formally typeset
Search or ask a question

Showing papers on "Insertion loss published in 1977"


Patent
Walter J. Tomlinson1
14 Apr 1977
TL;DR: In this paper, a multiplexer/demultiplexer for optical fibers is described that features a reflection diffraction grating and a graded refractive index rod in a rugged, compact assembly having low insertion loss and low crosstalk.
Abstract: A multiplexer/demultiplexer for optical fibers is disclosed that features a reflection diffraction grating and a graded refractive index rod in a rugged, compact assembly having low insertion loss and low crosstalk.

117 citations



Journal ArticleDOI
TL;DR: In this paper, an optical multiplexer for use with multimode optical fibers was constructed and tested using a blazed plane reflection grating with a single GRIN-rod lens.
Abstract: We have constructed and tested an optical multiplexer for use with multimode optical fibers. The device utilized a blazed plane reflection grating with a single GRIN‐rod lens, and was made from commercially available components. The wavelength spacing of the two channels was 27 nm, the insertion losses were ⩽2.4 dB, and the crosstalk was <−30 dB. Optimized versions of the device should be capable of providing at least four channels, with still lower insertion losses, in a rugged stable package 1–2 cm long by 2–4 mm in diameter.

57 citations


Journal ArticleDOI
TL;DR: The insertion loss for multibar magnetostatic surface-wave (m.s.w) transducers has been calculated from a "small" loss microstrip-transmission line model as mentioned in this paper.
Abstract: The insertion loss for multibar magnetostatic-surface-wave (m.s.s.w.) transducers has been calculated from a ‘small’-loss microstrip-transmission-line model. Experimental results for 2-bar and 8-bar parallel-strip and 4-bar π transducers are in excellent agreement with theoretical predictions. The 8-bar parallel-strip-transducer delay line gives a major bandpass response at 3.1 GHz, corresponding to an m.s.s.w. wavelength of 300 μm. The insertion loss is 11 dB, the 10 dB bandwidth is 70 MHz and adjacent sidelobes are 16 dB down.

49 citations


Journal ArticleDOI
TL;DR: An optical fiber connector with an adjusting mechanism using double eccentric tubes is reported, and a 0.57-dB average connecting loss between step index multimode fibers is obtained without matching material.
Abstract: An optical fiber connector with an adjusting mechanism using double eccentric tubes is reported. Tolerable impairment values of possible factors affecting connection loss are evaluated. The main factors of the connection loss are mutual core displacement and fiber axis tilt. By using a double eccentric adjusting mechanism, a 0.57-dB average connecting loss between step index multimode fibers is obtained without matching material. The connection loss can be attributed quantitatively to several impairment factors. Using a transparent thin film in the connecting section, the reflection can be reduced as low as about −25 dB, and the average connecting loss was improved to about 0.20 dB.

48 citations


Journal ArticleDOI
TL;DR: Full duplex transmission of television signals over a single optical fiber is demonstrated using directional couplers that possess high directivity and low insertion loss.
Abstract: Full duplex transmission of television signals over a single optical fiber is demonstrated The transmission link uses directional couplers that possess high directivity and low insertion loss

38 citations


Proceedings ArticleDOI
01 Jun 1977
TL;DR: In this article, a localised ion-beam milling has been used to increase the fundamental frequency of acoustic-bulk-wave resonators, and a monolithic filter in lithium niobate (Y+37°) and lithium tantalate (X) operating at 220 and 230 MHz has been realized.
Abstract: A localised ion-beam milling has been used to increase the fundamental frequency of acoustic-bulk-wave resonators. Monolithic filters in lithium niobate (Y+37°) and lithium tantalate (X) operating, respectively, at 220 and 230 MHz have been realised. The relative bandwidth is equal to 1% and the insertion loss is about 4 dB. An a.t.-cut quartz resonator working in the fundamental mode at 270 MHz with a Q-factor of 12 000 has also been obtained. In this case, the vibrating membrane is 6 μm thick, with a centre portion of diameter 2.5 mm.

38 citations


Journal ArticleDOI
TL;DR: In this article, an optical diplexer for injection of a local oscillator into a mixer, useful in the submillimeter and short millimeter range, is described, which has very low insertion loss for both the signal and L.O.
Abstract: An optical diplexer for injection of a local oscillator into a mixer, useful in the submillimeter and short millimeter range, is described. It has very low insertion loss for both the signal and local oscillator (L.O.) and high rejection of L.O. noise. Measured performance of a unit tested at 337 GHz indicates ~.2 dB loss for both inputs and 20 dB noise rejection.

36 citations


Journal ArticleDOI
TL;DR: In this paper, two types of Faraday rotators were used: one was composed of two permanent magnets, the other of a closed magnetic circuit with a permanent magnet, and 2.0 dB insertion loss and 30 dB isolation ratio at 1.15?m wavelength have been obtained.
Abstract: Compact Faraday rotation isolators have been developed for near-infrared radiation. Two types of Faraday rotators were used: one was composed of two permanent magnets, the other of a closed magnetic circuit with a permanent magnet. 2.0 dB insertion loss and 30 dB isolation ratio at 1.15 ?m wavelength have been obtained.

30 citations


Journal ArticleDOI
TL;DR: In this article, an analysis and design procedure for a mode transducer which converts the rectangular TE10 mode into the circular TE01 mode is presented, and an experimental model has been designed using the procedure and the measured performance, 0-2 dB average insertion loss from 33 to 50 GHz, is a significant improvement upon previously reported designs.
Abstract: An analysis and design procedure are presented for a mode transducer which converts the rectangular TE10 mode into the circular TE01 mode. The field analysis leads to an explicit evaluation of the transducer's s matrix. An experimental model has been designed using the procedure and the measured performance, 0-2 dB average insertion loss from 33 to 50 GHz, is a significant improvement upon previously reported designs.

30 citations


Journal ArticleDOI
TL;DR: To avoid deviations in characteristics due to splices a simple and effective mode scrambler was fabricated and each mode's output waveform was found to be the same as the total output wave form.
Abstract: Mode conversion at a splice was measured. Even the best splice, whose transmission loss was less than 0.01 dB, caused a mode conversion equaling about 11% of the total power. Spliced fiber transmission characteristics were influenced by the splicing conditions. To avoid deviations in characteristics due to splices a simple and effective mode scrambler was fabricated. Its insertion loss was less than 0.3 dB for a laser diode. Each mode’s output waveform was found to be the same as the total output waveform.

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate the combining of optical power from three input optical fibers to a single trunk fiber using fibers of different core/cladding diameters in a biconical taper configuration.
Abstract: Efficient combining of optical power from three input optical fibers to a single trunk fiber is demonstrated using fibers of different core/cladding diameters in a biconical taper configuration. The combiners have insertion loss less than 1 dB and optical isolation greater than −50 dB.

Patent
Vitaly Stachejko1
29 Jun 1977
TL;DR: In this paper, a hybrid coupled phase shifter for introducing a predetermined phase shift in a microwave frequency signal includes a four port transmission line network, where RF input and output terminals are connected to two of the ports and a pair of PIN diodes connected to the other ports.
Abstract: A hybrid coupled phase shifter for introducing a predetermined phase shift in a microwave frequency signal includes a four port transmission line network. RF input and output terminals are connected to two of the ports and a pair of PIN diodes connected to the other ports. The diodes are biased from a conducting to a nonconducting state to provide a reflective phase shift in the microwave signal. Highly resistive material is suitably disposed on the transmission lines such that at the diode conducting state the resistive material is decoupled from the RF power and coupled at the diode non-conducting state to a predetermined value to thereby balance the insertion loss between the diode switching states.

Journal ArticleDOI
TL;DR: In this article, the authors describe the development of an electromagnetic simulator for accurate generation of broadband suspectibility test fields within a shielded environment, which consists of a large, 3 m X 3m X 6 m, rectangular transverse electromagnetic (TEM) transmission cell that is loaded with RF absorber to suppress multimoding at frequencies above the cell's waveguide cutoff or resonant frequencies.
Abstract: This paper discusses the development of an electromagnetic simulator for accurate generation of broad-band suspectibility test fields within a shielded environment. The simulator consists of a large, 3 m X 3 m X 6 m, rectangular transverse electromagnetic (TEM) transmission cell that is loaded with RF absorber to suppress multimoding at frequencies above the cell's waveguide cutoff or resonant frequencies. The paper describes the measurement facility and technique, and the experimental verification of pertinent test paramenters such as system VSWR, insertion loss, and test field uniformity. The measurement system is anticipated to provide swept, automated susceptibility measurements of electronic equipment to CW, pulsed, and EMP fields within the frequency band, 10 kHz to 1 GHz.

Journal ArticleDOI
TL;DR: Low-loss surface-acoustic-wave (SAW) filters with loss as low as -0.6 dB at 35 MHz, -2.3 dB at 320 MHz, and -50 dB sidelobes are commonly constructed as discussed by the authors.
Abstract: For several years surface-acoustic-wave (SAW) devices have looked promising as future components for receiver front-end and intermediate frequency filters. However, high insertion loss and a time domain triple transit signal have limited the utilization of these devices. The low loss SAW filter overcomes both previous problems and is a milestone in electronic component development. Filters with loss as low as -0.6 dB at 35 MHz, -2.3 dB at 320 MHz, and -50 dB sidelobes are routinely constructed. This paper discusses surface-wave filters in general, and then specifically the design of low loss SAW filters.

Journal ArticleDOI
TL;DR: In this paper, a two-dimensional mathematical model for estimating the scattering of plane acoustic waves from an infinite, uniform, plane grating of compliant, elliptically, cylindric shells is developed.
Abstract: A two‐dimensional mathematical model for estimating the scattering of plane acoustic waves from an infinite, uniform, plane grating of compliant, elliptically, cylindric shells is developed. Calculations from the model are found to be in good agreement with insertion loss measurements of experimental arrays. The array is shown to be analogous to a multituned acoustic‐band rejection filter that has the shell’s fundamental flexural mode in the array for its center frequency. Low‐frequency approximations are also included. Conditions for an ultrawide resonance bandwidth having very high array resonance reflectivity are considered and an alternative application for compliant tube gratings, as an acoustic window that provides mechanical shading for a sonar receiving array, is discussed.

Proceedings ArticleDOI
01 Jan 1977
TL;DR: In this paper, a low-loss, high-coupling mode whose insertion loss is less than the Rayleigh-type surface acoustic wave was found, and the experimentally determined coupling (v/v) for this mode is almost a factor of three times that of the SAW.
Abstract: : Experimental measurements of 345 MHz surface acoustic waves propagating along the X-axis of Z-cut lithium niobate have revealed the existence of a low-loss, high-coupling mode whose insertion loss is less than the Rayleigh-type surface acoustic wave. When the double electrode of quarter-wavelength transducers were excited at the third overtone at 1035 MHz, the insertion loss of this mode was about 10 dB less than that of the SAW. The experimentally observed velocity of this mode was 4375 m/sec, considerably higher than the metalized SAW velocity of 3800 m/sec, but in excellent agreement with the theoretical calculated metalized pseudo SAW velocity. The experimentally determined coupling (v/v) for this mode is almost a factor of three times that of the SAW. This volume mode is in low-loss, broadband signal processing devices. (Author)

Proceedings ArticleDOI
01 Jan 1977
TL;DR: In this paper, the authors describe in detail the techniques necessary to achieve 60-70 dB sidelobe SAW filters operating in the UHF Region using withdrawal weighted transducers either as both input and output of the filter or in combination with overlap apodized transducers plus a thorough understanding and control of second order effects.
Abstract: : In order to avoid frequency spurious signals in bandpass filtering applications, low out-of-band sidelobes are necessary. The purpose of the present paper is to describe in detail the techniques necessary to achieve 60-70 dB sidelobe SAW filters operating in the UHF Region. These techniques include the use of withdrawal weighted (WW) transducers either as both input and output of the filter or in combination with overlap apodized transducers plus a thorough understanding and control of second order effects. The utility of these procedures will be illustrated by a description of the design, fabrication and testing of a 335 MHz, 0.34 percent bandwidth, 15 dB insertion loss, SAW filter on ST quartz having sidelobes and all other spurious (electromagnetic feedthru and 'bulk' mode interference) at least 63 dB below the output. In addition, experimental examples of design parameter variations and second order effects will be presented and correlated with theory where appropriate.

Proceedings ArticleDOI
21 Jun 1977
TL;DR: In this article, a surface acoustic wave slanted transducer pulse compressor with the power flat to within 1/2 dB over a 66% bandwidth is reported, which uses no matching networks and has -27 dB insertion loss with linear time delay over the band.
Abstract: A surface acoustic wave slanted transducer pulse compressor with the power flat to within 1/2 dB over a 66% bandwidth is reported in this paper. It uses no matching networks and has -27 dB insertion loss with linear time delay over the band.



Proceedings ArticleDOI
01 Jan 1977

Journal ArticleDOI
F. Auracher1, H.-H. Witte1
TL;DR: An optical coupler suitable for use as an access coupler in a data bus T-system with single multimode fibers as transmission lines and takes advantage of a simple, sufficiently reproducible, and cheap planar photolithographic process.
Abstract: We report an optical coupler suitable for use as an access coupler in a data bus T-system with single multimode fibers as transmission lines. The in- and out-coupling factors are determined by a lateral displacement of the main trunk-fibers which are butt joined. The fabrication of the coupler takes advantage of a simple, sufficiently reproducible, and cheap planar photolithographic process. Using fibers with 100-μm o.d. and 90-μm core diam a total insertion loss of about 1.5 dB and an out-coupling of about –14 dB was measured with a lateral displacement of 20 μm.

Journal ArticleDOI
Larry A. Coldren1
TL;DR: Grooved-grating, wave-guided s.a.w. resonators are coupled by the evanescent fields of singlemode slot waveguides formed by layers of MgO on SiO2 substrates as mentioned in this paper.
Abstract: Grooved-grating, waveguided s.a.w. resonators are coupled by the evanescent fields of single-mode slot waveguides formed by layers of MgO on SiO2 substrates. Except for higher out-of-band levels, the transfer characteristics of these devices compare favourably with alternative monolithically coupled s.a.w.-resonator geometries. A 4-pole response with a 3 dB bandwidth < 20 kHz and insertion loss < 6 dB is illustrated at 131.5 MHz.

Journal ArticleDOI
TL;DR: In this article, a localised ion-beam milling has been used to increase the fundamental frequency of acoustic-bulk-wave resonators, and a monolithic filter in lithium niobate (Y+37°) and lithium tantalate (X) operating at 220 and 230 MHz has been realized.
Abstract: A localised ion-beam milling has been used to increase the fundamental frequency of acoustic-bulk-wave resonators. Monolithic filters in lithium niobate (Y+37°) and lithium tantalate (X) operating, respectively, at 220 and 230 MHz have been realised. The relative bandwidth is equal to 1% and the insertion loss is about 4 dB. An a.t.-cut quartz resonator working in the fundamental mode at 270 MHz with a Q-factor of 12 000 has also been obtained. In this case, the vibrating membrane is 6 μm thick, with a centre portion of diameter 2.5 mm.

Book ChapterDOI
TL;DR: In this article, the insertion loss of the InSb mixer can be as low as 7 dB, which is substantially less than that of other readily available millimeter wave mixers.
Abstract: Publisher Summary The basic characteristics of the submillimeter detector do not change as they depend critically upon the purity of the available InSb, which is not improved upon. More attention is given to heterodyne techniques where it is shown that the insertion loss of the InSb mixer can be as low as 7 dB, which is substantially less than that of other readily available millimeter wave mixers. The performance is improved by a careful design of the element mounting to optimize the absorption of the radiation. In applications where the short response time is not required (as in most spectroscopy) an alternative method of obtaining a highly effective responsivity is to step up the impedance of the detector by means of a transformer cooled in the liquid helium. It is cooled to eliminate noise associated with its loss components.

Journal ArticleDOI
TL;DR: In this article, a simple model has been used to investigate this question in which the baffle is taken to be a layer of lossless fluid, and the reduction is pressure caused by the layer is calculated.
Abstract: An effective baffle must have a high insertion loss which is usually measured with normally incident plane sound waves. In some applications the following question arises. Is a baffle which has a high acoustic insertion loss also effective when used in other situations where acoustic insertion loss is not the direct requirement? For example, can the pressure fluctuations produced in a fluid by flexural vibrations in a plate be effectively reduced by covering the plate with an acoustic baffle? A simple model has been used to investigate this question in which the baffle is taken to be a layer of lossless fluid. For evaluating flexural wave baffling this layer is in contact with a vibrating plate, and the reduction is pressure caused by the layer is calculated. The plane wave acoustic insertion loss is also calculated for the same layer and compared with the flexural wave insertion loss. It is found that the baffling achieved in these two situations is nearly the same for some types of plate vibrations, but quite different for other types. [Work supported by CNM.]


Patent
10 Aug 1977
TL;DR: In this paper, a method to reduce the insertion loss while controlling the degree of coupling by removing the clad between optical fibers and disposing clads of different refractive indices was proposed.
Abstract: PURPOSE: To reduce the insertion loss while controlling the degree of coupling by removing the clad between optical fibers and disposing clads of different refractive indices. COPYRIGHT: (C)1979,JPO&Japio

Journal ArticleDOI
TL;DR: In this article, an acoustic surface wave filter for the use of TV-intermediate frequency at 58 MHz was fabricated using an rf-sputtered ZnO film overlying the interdigital electrodes and the wave path on a glass substrate, and its fundamental properties for practical application were studied.
Abstract: The acoustic-surface-wave filter for the use of TV-intermediate frequency at 58 MHz was fabricated using an rf-sputtered ZnO film overlying the interdigital electrodes and the wave path on a glass substrate, and its fundamental properties for practical application were studied. The average and easily reproducible insertion loss characteristics are as follows: 16 dB at the minimum, 5(+16) dB at chromatic and picture signal carrier frequencies, 15(+16) dB at sound signal carrier frequency, more than 55(+16) dB at trap frequencies for adjacent channels, and 35(+16) dB at the maximum side lobe. The triple transit echo suppression is more than 35 dB. The temperature coefficient of the frequency characteristic is less than -30 ppm/°C. 500 days of aging has shown no significant change in the filter. Another type of filter for the use in U.S.A. is also fabricated by the same system.