Showing papers on "Insertion loss published in 1973"
TL;DR: In this paper, a broad-band linear FM dispersive filter with a time-bandwidth (TB) product of 1000 has been proposed, which can achieve a CW insertion loss of less than 35 dB.
Abstract: The development of a low-loss broad-band linear FM dispersive filter having a time-bandwidth (TB) product of 1000 is discussed. Two systems applications for highly dispersive linear FM filters--pulse compression RADAR and a microscan receiver--are discussed with emphasis on filter performance requirements. The principal factors which influence the design of surface-wave filters are reviewed and theoretical design procedures are outlined. The 1000:1 filters, which are implemented on strong-coupling YZ lithium niobate, typically meet the design goal of a 100-MHZ rectangular passband and have a CW insertion loss of less than 35 dB. Measured data are presented for the filter performance in a pulse-compression loop and in a prototype broad-band microscan (compressive) receiver.
44 citations
TL;DR: In this paper, a new type of nonlinear delay-line correlator is described which makes use of a tapped piezoelectric surface-acoustic-wave delay line and a series chain of forward-biased semiconductor diodes.
Abstract: A new type of nonlinear delay‐line correlator is described which makes use of a tapped piezoelectric surface‐acoustic‐wave delay line and a series chain of forward‐biased semiconductor diodes Nonlinear signal mixing in the diode chain is utilized to perform serial product convolution or correlation of arbitrary signal modulation applied at two input ports Because of the large nonlinearity available with semiconductor diodes, insertion loss for the new correlator is relatively low, approximately 25 dB for the initial experiments reported here Convolution and correlation experiments are described for an eight‐tap correlator operating with input and mixing frequencies in the 30‐ to 60‐MHz range
41 citations
12 Jun 1973
37 citations
01 Oct 1973
TL;DR: In this article, a novel filter device, employing bulk acoustic waves, has been demonstrated experimentally, which provides bandwidths of several percent at HF with low insertion loss, and is simple in construction, miniature and robust.
Abstract: A novel filter device, employing bulk acoustic waves, has been demonstrated experimentally. Inherently simple in construction, miniature and robust, it provides bandwidths of several percent at HF with low insertion loss.
22 citations
TL;DR: In this article, a low-noise FET analogue switch is described which has been used to deal with some of the problems encountered in optimizing the design of a probe for a pulsed NMR spectrometer intended for work on solids.
Abstract: A low-noise FET analogue switch is described which has been used to deal with some of the problems encountered in optimizing the design of a probe for a pulsed NMR spectrometer intended for work on solids. The switch circuit has been used in association with two spectrometers, one for microsecond RF pulses and the other for RF pulsewidths of up to 1 s. In each case the resolution time achieved was limited by the transmitter coil ring down. The switch has negligible insertion loss when on and 84 dB attenuation at 15 MHz when off, thus affording good protection of the receiver system.
18 citations
TL;DR: In this article, the design, construction, calibration and performance of an impedance tube facility for precision measurement of both acoustic impedance and insertion loss of samples of acoustic material at high sound pressure levels is described.
15 citations
TL;DR: The ON-OFF ratio, insertion loss, and switching speed of polycrystalline ferroelectric ceramic PLZT electrooptic shutters fabricated with a zirconium to titanium ratio of 65 to 35 and a lanthanum concentration of approximately 8% were investigated as functions of voltage amplitude and duration.
Abstract: The ON-OFF ratio, insertion loss, and switching speed of polycrystalline ferroelectric ceramic PLZT electrooptic shutters fabricated with a zirconium to titanium ratio of 65 to 35 and a lanthanum concentration of ≈8% were investigated as functions of voltage amplitude and duration. Larger ON-OFF ratios (33 dB for dc mode) were observed for the chemically prepared material than for the mixed oxide material (18 dB). Similar results were observed in the pulsed mode. The relatively low insertion losses (4.5 dB) and fast half-wave retardation switching (≈1 μsec) are acceptable for many shutter applications. Observed variations of these characteristics with number of switching cycles are undesirable.
12 citations
Patent•
09 Oct 1973
TL;DR: In this paper, a nonlinear delay line correlator and convolver is described which comprises a tapped, piezoelectric surface acoustic wave delay line and an array of series or parallel connected forward biased semiconductor diodes.
Abstract: A nonlinear delay line correlator and convolver is described which comprises a tapped, piezoelectric surface acoustic wave delay line and an array of series or parallel connected forward biased semiconductor diodes. An interdigital signal transducer is connected to each end of the delay line and voltages are applied to each transducer to generate contra-flowing acoustic strain waves which are radiated toward an interaction region comprising a plurality of equi-spaced weakly coupled interdigital transducers, each transducer being connected to one diode. Nonlinear signal mixing in the diode array is utilized to perform serial product convolution or correlation of the signal modulation applied at the two signal input transducers. Because of the large nonlinearity of semiconductor diodes, insertion loss is relatively low. One feature of the diode correlator is a novel dual acoustic beam transducer which permits two separate acoustic beams to be generated without interaction therebetween except at the transducer taps.
11 citations
01 Jan 1973
10 citations
01 Oct 1973
10 citations
TL;DR: In this paper, an exploratory study aimed at building an LEC at approximately 4 GHz was successfully completed, with an insertion loss < 1 dB (minimum, 0.5 dB).
Abstract: The successful application of thin-film lumped-element circulators (LEC) at L band has led to the following question: How far can these devices be extended in frequency using our present beam-crossover technology? An exploratory study aimed at building an LEC at approximately 4 GHz was successfully completed. Preliminary tests showed a 20-dB band from 4.2 to 5 GHz with an insertion loss <1 dB (minimum, 0.5 dB). This includes fixture losses, which account for about 0.2 dB. The device has been tuned to operate above 5 GHz, and from the experiments it is concluded that a device of this type could be built at frequencies as high as X band. These devices are very small; at 4 GHz, the circulator junction is a 0.075- in diam.
TL;DR: In this article, the insertion loss and electronic saturation effects observed in the series-configuration diode correlator are described in terms of a simple 1st-order theory, and the results of this theory are favourably compared with experiments for an 8-tap diode correlation operating in the 30-60 MHz range.
Abstract: The insertion loss and electronic saturation effects observed in the series-configuration diode correlator are described in terms of a simple 1st-order theory. The results of this theory are favourably compared with experiments for an 8-tap diode correlator operating in the 30-60 MHz range.
TL;DR: In this article, a new type of device is described in which an acoustoelectric surface wave interacts with low energy free charges created on the surface of a piezoelectoric material.
Abstract: A new type of device is described in which an acoustoelectric surface wave interacts with low energy free charges created on the surface of a piezoelectric material. The experimental results obtained show that one of the most promising applications is an analog RF storage device for which several minutes of storage time have been achieved at 30 MHz on quartz with an internal insertion loss of 63 dB. If the width of the current pulse is large enough, direct attenuation of the surface wave may be measured due to the energy absorbed by the motion of secondary electrons. Experimental and theoretical results are presented. The limitations and the applications of the device to signal processing are discussed.
TL;DR: In this paper, a GaAs traveling-wave transistors have been used for the measurement of gain, noise figure, reverse attenuation, and phase control in the frequency range 8-18 GHz.
Abstract: Instantaneous gain, noise figure, reverse attenuation, and gain and phase control measurements in the frequency range 8-18 GHz have been performed on GaAs traveling-wave transistors. The broad-band high-gain nature of the device together with the requirement for several bias connections precluded the use of standard test fixtures, and resulted in a package design exhibiting less than 1-dB insertion loss over the band together with 75- to 90-dB internal isolation. Untuned X-band gain, noise figure, and reverse attenuation were 12 dB, 18 dB, and 32 dB, respectively, and the gain and phase could be electronically varied over a 35-dB and 360/spl deg/ range. When RF tuning was employed, the gain, on the average, improved by 10 dB.
TL;DR: In this article, the authors describe analytical and experimental results obtained on a broadband ferrite limiter at K u band, which utilizes a synchronously tuned waveguide bandpass structure, aimed at providing protection for communications and electronic warfare systems over a bandwidth from 12 to 30 percent at k u -band frequencies.
Abstract: This investigation describes analytical and experimental results obtained on a broadband ferrite limiter at K u band which utilizes a synchronously tuned waveguide bandpass structure. This device is aimed at providing protection for communications and electronic warfare systems over a bandwidth from 12 to 30 percent at K u -band frequencies. The circuit consists of a series of three cavities in a waveguide transmission line, the coupling being accomplished via the irises or symmetrical inductive slits between cavities. Because of this cavity structure, the observed threshold power levels have been reduced by an order of magnitude. By utilizing a combination of single crystal YIG and lithium ferrite rods, the threshold power for limiting varies from 0.75 W at 16.0 GHz to 2.0 W at 17.0 GHz with an insertion loss of 0.9 dB.
TL;DR: In this paper, a simple bandpass filter system that is suitable to resolve the radiation emitted by far-infrared (4-0.1 mm wavelength) source that has a relatively flat emission spectrum is described.
Abstract: A simple bandpass filter system that is suitable to resolve the radiation emitted by far‐infrared (4–0.1 mm wavelength) source that has a relatively flat emission spectrum is described. This system, which has a resolving power of 2, an insertion loss of 3 dB, and an acceptance angle of 7°, was used in conjunction with a cooled InSb detector to measure the temperature vs wavelength characteristics of a mercury arc lamp from 4 to 0.3 mm.
04 Jun 1973
TL;DR: In this article, a technique particularly applicable at millimeter wavelengths was described for electronically varying the phase shift per unit length in rectangular waveguide using a distributed PIN diode, and the design, construction, and experimental evaluation at 140 GHz were described.
Abstract: A technique particularly applicable at millimeter wavelengths is described for electronically varying the phase shift per unit length in rectangular waveguide using a distributed PIN diode. Design, construction, and experimental evaluation at 140 GHz are described.
04 Jun 1973
TL;DR: In this paper, the design and performance of a 3mm H-plane waveguide junction circulator was described, with appropriate partial height ferrite and transformer dimensions, 0.5 to 1 dB insertion loss, 23 to 30 dB maximum isolation and 3 to 5 GHz 20 dB isolation bandwidth over the 80-100 GHz frequency range.
Abstract: This paper describes the design and performance of a 3mm H-plane waveguide junction circulator which exhibited, with appropriate partial height ferrite and transformer dimensions, 0.5 to 1 dB insertion loss, 23 to 30 dB maximum isolation and 3 to 5 GHz 20 dB isolation bandwidth over the 80-100 GHz frequency range. Application of the resonant mode theory of H-plane waveguide circulator operation indicated that said circulator resonated in the axial "compact turnstile" mode, with strong correlation between theoretical and measured center frequencies.
Patent•
26 Sep 1973
TL;DR: In this paper, a low loss high-Q filter with a restricted bandpass of 7.25-7.75 GHz with an insertion loss of 0.5db, an out-of-band rejection greater than 80db and negligible spurious responses in-band.
Abstract: A low loss high-Q filter is disclosed herein having a restricted bandpass of 7.25-7.75 GHz with an in-band insertion loss of 0.5db, an out-of-band rejection greater than 80db and negligible spurious responses in-band. This is accomplished by providing two types of directly coupled variable resonators. The first type of variable resonators includes a series of twelve right circular cylindrical cavity resonators directly coupled in series with each other. Two of the second type of variable resonators are provided with each of these second type of variable resonators being directly coupled to opposite ends of the series coupled cylindrical resonators. Each of these second type of variable resonators include three directly coupled rectangular waveguide cavity resonators.
01 Oct 1973
22 Apr 1973
22 Apr 1973
TL;DR: In this paper, a new feed concept is described which greatly simplifies the problem of commutating the RF distribution system of a cylindrical phased array, which consists of a circular parallel-plate radial transmission line with a central set of probes and a ring of peripheral probes.
Abstract: A new feed concept is described which greatly simplifies the problem of commutating the RF distribution system of a cylindrical phased array. The feed consists of a circular parallel-plate radial transmission line with a central set of probes and a ring of peripheral probes. The array of probes in the center can be phased to produce an amplitude distribution in the parallel-plate line in any given direction. Proper setting of only two phase shifters connected to the central probes can cause any sector of the peripheral probes to be excited with the proper amplitude distribution necessary to produce a directive pattern with low sidelobes as well as a monopulse difference pattern when the peripheral probes are connected, through collimating phase shifters, to the active radiating elements of a cylindrical array. The cylindrical array can be scanned through 360\deg in fine increments by continued indexing of the amplitude distribution generated by the central probes. Experimental L band hardware, built to prove the feed technique, is described. Nine central probes in a 0.25-inch thick 21-in diameter model produced a cardioid distribution and an orthogonal figure-eight distribution which could be commutated together by adjustment of two phase shifters. Measured insertion loss between the central probes and 48 peripheral probes showed only 0.1-dB loss over a 6-percent band. Coupling measurements between the three available central terminals indicated isolation between the various ports of 23-35 dB. The minimum insertion loss and the corresponding transmission phase between the central feed and the peripheral probes was shown to be independent of the setting of the two control phase shifters which were set to have conjugate phase shift.
TL;DR: In this paper, a Fourier transform was used to convert the readings to either an impedance or insertion loss in the frequency domain, and the insertion loss is primarily the result of large skin effect impedance in the magnetically active portion of the signal path.
Abstract: High-frequency switches of the reed relay type have insertion losses of the order of 0.1 dB. The insertion loss is primarily the result of large skin effect impedance in the magnetically active portion of the signal path. This paper presents a novel time-domain reflectometer technique for measuring this skin effect impedance in the time domain then shows how a Fourier transform will convert the readings to either an impedance or insertion loss in the frequency domain. The method uses inexpensive equipment, is very accurate, and is fast since only a single voltage measurement at one instant of time is needed for the determination of the insertion loss at a desired frequency. Precision of at least 0.001 dB is achievable.
TL;DR: In this paper, the design of a high-power air-cooled microwave Y-junction circulator which is capable of operation at peak and average power levels of 800 kW and 800 W, respectively, is described.
Abstract: The design of a high-power air-cooled microwave Y-junction circulator which is capable of operation at peak and average power levels of 800 kW and 800 W, respectively, is described. The unit is an H-plane waveguide circulator which is externally air cooled. The circulator design employs a full-height substituted YIG rod with a center metal pin together with boron nitride matching transformers. The circulator exhibits an insertion loss of less than 0.4 dB, isolation greater than 22 dB, and a VSWR <1.26:1 over a 400-MHz bandwidth centered at 3.3 GHz. At high-power levels, the device exhibits insertion loss of less than 0.9 dB, isolation greater than 20 dB, and VSWR <1.25:1 at an indicative frequency within the operating bandwidth.
01 Aug 1973
TL;DR: In this paper, the authors describe work done during the second half of a 12-month investigation of the capabilities of time domain metrology in an automatic calibration system and evaluate sources of measurement error.
Abstract: : The report describes work done during the second half of a 12 month investigation of the capabilities of time domain metrology in an automatic calibration system. Sources of measurement error are isolated and evaluated through experiments. The most serious source, long term random error due to slight generator instability, is reduced by a circuit modification. Sebsequent insertion loss measurements on wideband coaxial attenuators show excellent agreement between time domain results and frequency calibration values over the range 0.4 to 8 GHz. Measurement results are also included for waveguide components and crystal detectors. Pulse generator development work on higher voltage solid state diodes and optimum pulse width determination are discussed. Descriptions are given of a new pulse generator with 8 V amplitude and 60 ps, -6 dB width, and a 2.5 ns time domain standard built for the U. S. Government. Recommendations for future work to improve and extend the frequency range of the present system are suggested.
04 Jun 1973
TL;DR: In this paper, theoretical and experimental results of TE/sub 02/ and TE/ sub 03/ mode filters for circular waveguides with large diameter are described. But the experimental results show that the insertion loss is less than 0.8 dB for the former and less than 1.4dB for the latter over the 40 to 80 GHz frequency range.
Abstract: This paper describes theoretical and experimental results of TE/sub 02/ and TE/sub 03/ mode filters for circular waveguides with large diameter. The experimental results show that the TE/sub 01/ insertion loss is less than 0.8 dB for the former and less than 0.4 dB for the latter over the 40 to 80-GHz frequency range. The attenuation loss of the undesired modes is more than 6 dB over the same frequency range for both filters.
30 Jun 1973
TL;DR: Theoretical and experimental studies on (1) mode filters for single-frequency Nd:YAG lasers, (2) wide-bandwidth optical modulators, and (3) laser communication systems and components are reported as mentioned in this paper.
Abstract: : Theoretical and experimental studies on (1) mode filters for single- frequency Nd:YAG lasers, (2) wide-bandwidth optical modulators, and (3) laser communication systems and components are reported. Stable single-frequency output power of 0.2 W is obtained from a Nd:YAG laser by using a combination of tilted etalon and a thin metallic film in the laser cavity. Detailed analyses have been made to reduce the insertion loss of mode filters to an absolute minimum so that efficiency can be increased. The electrooptic modulator uses a microwave interdigital filter structure and has a 1.2-GHz bandwidth. A new circuit design aimed at increasing modulation depth for a given rf power has been obtained. Theory indicates that the interferometric mode of modulation should increase efficiency over the birefringence mode; good experimental agreement has been obtained. Study of optical crystals has been initiated; no optical damage or beam distortion of LiNbO3 was observed under continuous radiation of 14 kW/sq. cm green light when the crystal was at 180C. Several laser communication system concepts and modulation formats have been selected for study. An annotated bibliography of these systems has been published.
01 Apr 1973
TL;DR: For the first time, the rf signal designer has the opportunity to perform signal processing at radar signal frequencies, with devices which are compatible with Gunn and IMPATT solid state signal sources.
Abstract: : The significance of this research and development to the Air Force derives from the need for small, lightweight solid state integrated circuit devices suitable for signal processing applications at Microwave frequencies. The work covered by this report was directed specifically at such devices operating at X band (8.0 to 12.4 GHz). The performance improvement was accomplished by improving the quality of epitaxial YIG films, increasing the knowledge of magnetostatic wave propagation in dielectric layered structures, and utilizing high energy product samarium cobalt magnets. During the period covered by this contract several devices were built and evaluated. These were: 1. A nondispersive delay line at 8.425 GHz with a delay of 124 nsec, an insertion loss of 20 dB, and a bandwidth of 45 MHz; 2. A dispersive delay line operating at 9.1 GHz with a 300 MHz linear dispersion of 175 nsec of differential delay. This device compressed a linear chirp by a factor of 30:1 and weighted the adjacent sides lobes to -20 dB; 3. A two tap delay line having a nondispersive delay of 50 nsec and 80 nsec. The success of these devices in terms of size and operating frequency represents a considerable increase in the state of the art. For the first time, the rf signal designer has the opportunity to perform signal processing at radar signal frequencies, with devices which are compatible with Gunn and IMPATT solid state signal sources.