Showing papers on "Insertion loss published in 1974"
TL;DR: The conical metallic radome presented in this article is 6 ft 4 in long and has a base diameter of 25.5 in, and the resonant slotted surface of the radome consists of 90 percent metal.
Abstract: The results of research and development, fabrication, and measured transmission performance for a specific streamlined metallic radome are contained in this paper. The measured results presented demonstrate that high-quality radome transmission performance can be attained with a streamlined metallic radome. The conical metallic radome presented is 6 ft 4 in long and has a base diameter of 25.5 in. The specially designed resonant slotted surface of the metallic radome consists of 90 percent metal and, for frequencies within its operating band, the radome permits transmission with any signal polarization over a wide range of scan angles. At its 8.90 GHz resonant frequency the metallic radome introduces less than 0.5 dB signal loss and less than 2 mrad boresight error. This radome has been purposely designed for operation over a narrow frequency band. Over a 200 MHz band, measured insertion loss and boresight error values of 1 dB and 6 mrad, respectively, are attained.
117 citations
NEC1
TL;DR: In this paper, the tensor permeability in a strong uniaxial field of hexagonal ferrite has been investigated at mm-wave frequencies and the dependence of the circulator bandwidth on an applied field is determined.
Abstract: Hexagonal ferrite is used for a circulator at mm-wave frequencies. No external magnet is needed. The center frequency is 73.5 GHz, the bandwidth over which the isolation is greater than 20 dB is 2.4 GHz, and the insertion loss is 1.1 dB at the center frequency. The tensor permeability in a strong uniaxial field is determined. The dependence of the circulator bandwidth on an applied field is determined to show that the large uniaxial field of hexagonal ferrite contributes to the wideband performance at mm-wave frequencies.
55 citations
01 Jan 1974
42 citations
TL;DR: In this paper, the design and performance of two microstrip semiconductor phase shifters operating at S band and UHF are described, and the characteristics of two new microwave semiconductor switching devices, the field effect diode (FED) and the resistive gate switch are described.
Abstract: The design and performance of two microstrip semiconductor phase shifters operating at S band and UHF are described. The S-band diode phase shifter uses thick-film metallization on a 99.5-percent alumina substrate and uses series coupled diodes for the small bits and constant phase frequency switched life bits for the three large bits. The 4-bit UHF phase shifter uses eight p-i-n diodes mounted in a low dielectric constant microstrip circuit and operates at a power level of 8 kW peak, 240 W average, and has an average insertion loss of 0.7 dB. Phase and VSWR distributions on 800 units produced are also given. The characteristics of two new microwave semiconductor switching devices, the field-effect diode (FED) and the resistive gate switch are described. These devices operate with only a voltage change. Design and performance of an SP2T switch and 3-bit phase shifter using the field-effect diode are presented.
30 citations
TL;DR: In this article, a frequency independent damping parameter, λ, for MSSW's has been related to the dB/μsec loss, and the relationship between insertion loss and time delay is linear.
Abstract: Propagation loss measurements of magnetostatic surface waves are reported and related to recent theory. They are also compared with other published loss data. Recently, a frequency independent damping parameter, λ, for MSSW's has been related to the dB/μsec loss. Using our data we find \lambda = 0.88 \times 10^{4} Hz. This compares favorably with an estimated value of 1.163 \times 10^{4} Hz based on FMR linewidth. A tabulation is provided of other experimental low loss measurements which relate to MSSW propagation loss. For our measurements two independent measuring techniques were employed which allow propagation and coupling losses to be separated. One technique is independent of coupling loss and measures the power difference of a single pulse over a given time delay differential. The second technique is dependent on coupling conditions. The later technique measures total insertion loss versus time delay. The relation between insertion loss and time delay is linear. The proportionality constant gives the propagation loss and the intercept the coupling loss. At 6 GHz we measure a propagation loss of 23 dB/μsec and a two way coupling loss of 10 dB. The characteristics of a 6 GHz delay line are described.
27 citations
TL;DR: Measurements that have been performed indicate that hot-pressed ferromagnetic CdCr(2)S(4) would be a useful Faraday optical isolator material for laser systems at 10.6 microm, introducing less than 2 dB insertion loss due to optical absorption at that wavelength.
Abstract: Measurements that have been performed indicate that hot-pressed ferromagnetic CdCr2S4 would be a useful Faraday optical isolator material for laser systems at 10.6 μm. A large-aperture, liquid-nitrogen-cooled isolator, requiring modest magnetic fields with material of optimum thickness, would provide isolation in excess of 30 dB with insertion loss due to optical absorption in the active element of less than 3 dB. Consideration of its figure of merit indicates that hot-pressed CdCr2S4 could be used as an isolator at 1.06 μm, introducing less than 2 dB insertion loss due to optical absorption at that wavelength.
17 citations
TL;DR: In this paper, a 16-channel surface-acoustic-wave grating filter bank was constructed on four y-cut LiNbO3 crystals, each channel has a 4dB bandwidth of 6.7 MHz.
Abstract: A 16-channel surface-acoustic-wave grating-filter bank has been constructed on four y-cut LiNbO3 crystals. Each channel has a 4dB bandwidth of 6.7 MHz. The insertion loss at the peak of the passband of each channel is −32 dB, ±1.2 dB. The centre frequencies are 6.7 MHz apart and span the range 150–250 MHz. This filter has been incorporated in a realtime spectral analyser.
14 citations
TL;DR: The effect of dielectric losses, conductor thickness, and frequency dispersion on the performance of edge-coupled microstrip directional couplers and interdigital filters have been determined in this paper.
Abstract: The effect of ohmic and dielectric losses, conductor thickness, and frequency dispersion on the performance of edge-coupled microstrip directional couplers and interdigital filters have been determined in this short paper. The odd- and even-mode attenuation constants due to ohmic losses in the conductor have been calculated using Wheeler's inductance formula. The theoretical results for the characteristic impedance and propagation constants are in good agreement with the experimental results of Napoli and Hughes. Among the parameters that can be calculated from this theory are the isolation, directivity, and coupling coefficients of lossy directional couplers and the midband insertion loss of interdigital filters.
12 citations
Patent•
08 Nov 1974
TL;DR: In this paper, the inductance value of the inductor was chosen such that minimum transducer insertion loss is achieved at the center frequency of the midband channel, subject to the constraint that the insertion losses of all the remaining channels, measured at their respective center frequencies, lie at or near the above optimum value within an acceptable prespecified margin.
Abstract: The input transducers of a multichannel surface acoustic wave device are electrically connected in a series or series-parallel circuit arrangement and are connected to a single channel electromagnetic wave transmission line through an inductor. The inductance value of the inductor is chosen such that minimum transducer insertion loss is achieved at the center frequency of the midband channel. The circuit arrangement is selected which achieves optimum coupling to the midband channel subject to the constraint that the insertion losses of all the remaining channels, measured at their respective center frequencies, lie at or near the above optimum value within an acceptable prespecified margin.
12 citations
01 Oct 1974
TL;DR: In this paper, a traveling-wave structure comprised of an array of high-Q dielectric resonators yields a low level insertion loss of less than 1 db at all frequencies.
Abstract: Passive single crystal, ferrite limiters have been developed in several frequency ranges with instantaneous bandwidths of better than 20%, limiting thresholds of less than +20 dbm, and dynamic ranges of more than 20 db. A compact, traveling-wave structure comprised of an array of high-Q dielectric resonators yields a low level insertion loss of less than 1 db at all frequencies. Low linewidth spheres of yttrium-iron-garnet (YIG) or lithium ferrite are placed in a region of high r.f. magnetic field of each dielectric resonator, and a permanent magnet serves to bias the ferrites to the non-linear region of subsidiary-resonance absorption. Structures of this type have been built for the ranges of 4.4 to 5.0 GHz, 8 to 10 GHz, 10 to 12 GHz, 12 to 14 GHz and 14 to 16 GHz. All limiters exhibit the excellent frequency selectivity characteristics of YIG devices.
10 citations
Patent•
30 Sep 1974
TL;DR: In this paper, a high frequency coaxial cable exhibiting a low insertion loss and a low reflection coefficient, and incorporating an improved construction providing for convenient adjustment of impedance, is presented for high frequency communications.
Abstract: A high frequency coaxial cable exhibiting a low insertion loss and a low reflection coefficient, and incorporating an improved construction providing for convenient adjustment of impedance.
01 Jan 1974
TL;DR: In this article, an electrooptic intensity modulator using lithium niobate has been developed for applications in binary fiber optical digital communications at the wavelength of 1.06 µm. The modulator was driven by a compact transistor amplifier, temperature dependence of the static birefringence was minimized, and the optical bias was made adjustable by a dc voltage superposed on the signal.
Abstract: An electrooptic intensity modulator using lithium niobate has been developed for applications in binary fiber optical digital communications at the wavelength of 1.06 µm. We have shown that many shortcomings generally associated with electro-optic modulators can be surmounted. The modulator was driven by a compact transistor amplifier, temperature dependence of the static birefringence was minimized, and the optical bias was made adjustable by a dc voltage superposed on the signal. The modulator has been operated at 70-Mb/s pulse rate and 100-percent modulation, its extinction ratio is better than 40 to 1 and the optical insertion loss is about 1 dB.
TL;DR: In this article, a p-i-n diode phase shifter is described for low cost production for use in X-band phasedarray systems, which is designed to make maximum use of photoetched circuit components and low cost materials, and is well suited for assembly on a fully automated assembly line.
Abstract: This paper presents a description of a p-i-n diode phase shifter that was designed for low cost production for use in X-band phased-array systems. The phase shifter is designed to make maximum use of photoetched circuit components and low cost materials, and is well suited for assembly on a fully automated assembly line. The salient features of this phase shifter are a printed-circuit transmission structure and inexpensive RF connectors that are integrated into the circuit package. The microwave performance characteristics are generally superior to those of equivalent devices; a useful bandwidth of 40 percent with an average insertion loss of 1.6 dB has been demonstrated with 3-bit units.
TL;DR: Sodium-borosilicate glasses have been converted into fibres, with very small incremental optical loss as discussed by the authors, by converting them to fibres with a very small optical loss.
Abstract: Sodium-borosilicate glasses have been converted into fibres, with very small incremental optical loss.
Patent•
NEC1
TL;DR: In this article, a thin-film circulator with three symmetrically arranged lumped parameter LC circuits fabricated by thin film techniques and having the junctions of the LC elements interconnected through conductive paths, such as inductors, is presented.
Abstract: A circulator preferably fabricated using thin film techniques. Broad-band isolation and insertion loss characteristics are obtained in the gigahertz frequency range by replacing the conventional series resonant circuit typically employed in circulation, with three symmetrically arranged lumped parameter LC circuits fabricated by thin-film techniques and having the junctions of the LC elements interconnected through conductive paths, such as inductors, for example.
TL;DR: In this article, surface-wave velocities and electromechanical-coupling coefficients on the three principal planes of Bi12SiO20 are presented as a function of the propagation direction.
Abstract: Surface-wave velocities and electromechanical-coupling coefficients on the three principal planes of Bi12SiO20 are presented as a function of the propagation direction. The measured values show that Bi12SiO20 is a more useful material for acoustic-surface-wave devices than the better known Bi12GeO20. It has a higher electromechanical-coupling coefficient, so that devices made with it have a lower untuned insertion loss.
TL;DR: In this article, a crossoverless Iumped-element circulator is proposed, which can be made without sophisticated thin-film processing and can be described by a "delta connected" equivalent circuit.
Abstract: It is proposed to construct a simple "crossoverless" Iumped-element circulator, which can be made without sophisticated thin-film processing. The circulator can be described by a "delta connected" equivalent circuit. A simple capacitor arrangement can be used to influence the three eigenvalue phases of the circulator independently, thus permitting this circulator to be maximized systematically. A set of computer-generated eigenvalues gives insight into the behavior of the device under varying operating conditions. Preliminary measurements using a very simple pattern on a 0.650-in-diam ferrite substrate show a 20-dB bandwidth of 10 percent and an insertion loss < 1 dB (0.3 dB/min) at L band.
TL;DR: In this paper, a passive, frequency selective limiter with low power limiting thresholds and better than 20% bandwidth for several frequency ranges was proposed, which utilizes the subsidiary resonance absorption phenomenon in low linewidth YIG (yttrium-iron-garnet) spheres.
Abstract: Passive, frequency selective limiters have been built with low limiting thresholds and better than 20% bandwidth for several frequency ranges. These devices utilize the subsidiary‐resonance absorption phenomenon in low linewidth YIG (yttrium‐iron‐garnet) spheres. The spheres are placed at the center of dielectric resonators, where intense R.F. magnetic field are generated with relatively low power input. Thus low power limiting thresholds are achieved over a broad frequency range when the spheres are biased properly with a permanent magnet. The bandpass characteristics of these devices are achieved by forming a traveling wave structure of closely spaced dielectric resonators. Limiters of this type are now in operation covering the 8 –10 GHz and 10 – 12 GHz ranges with a small‐signal insertion loss of less than 1 db, a limiting level of 20 dbm or less, and a dynamic range of about 20 db. A small signal is compressed by less than 1 db if it is more than 10 MHz away from 30 dbm limited signal. A similar device has been built at C‐band with a limiting level of less than 12 dbm.
TL;DR: In this paper, the effects of the circuit structure and the physical properties of the resonator on the characteristics of a circuit are investigated, and it is shown that the maximum dissipation loss of a resonator is just one half of the input power.
Abstract: The general formulas for both 4-port magnetic-resonator circulators and 2-port magnetic-resonator bandpass filters (BPF's) are given. The effects of the circuit structure and the physical properties of the resonator on the characteristics of the circuit are investigated. The maximum dissipation loss of the resonator is just one half of the input power. Contrary to the results shown in previous reports, it is understood that for a given resonator, there exists an optimum value of the external Q of the circuit and also that a polycrystalline magnetic resonator may be useful for the nonreciprocal circuit, if the product of unloaded Q and saturation magnetization has a sufficiently large value. The requirements for the insertion loss (IL), the reverse loss (RL), and the reflection at the center frequency are introduced, and then the necessary conditions of resonator loss and the limitations of 3-dB bandwidth and available range are clarified.
01 Jan 1974
TL;DR: A generalized synthesis technique for the design of amplifier matching networks, which allows flexible topology, arbitrary gain shape and parisitic absorption capability, will be presented.
29 Jul 1974
TL;DR: In this paper, the design of low cost, compact surface acoustic wave frequency multiplexers is described and the frequency selective properties of surface wave filters are used to achieve low inband (high-Q) loss and high outband rejection.
Abstract: : The design of low cost, compact surface acoustic wave frequency multiplexers is described The frequency selective properties of surface wave filters are used to achieve low inband (high-Q) loss and high outband rejection Observations made on measured transducer input impedances are used to affect a simple insertion loss minimization technique applicable to N coupled surface wave filters (Author)
TL;DR: In this article, low-cost construction techniques for S-band twin-slab ferrite phase shifters are presented along with an experimental comparison of garnet and lithium-ferrite materials.
Abstract: Low-cost construction techniques for S-band twin-slab ferrite phase shifters are presented along with an experimental comparison of garnet and lithium-ferrite materials. A 3-bit phase shifter with lithium-ferrite material, which is approximately half the price of garnet material, had a measured loss of 0.4 dB and a peak power handling of 4.5 kW.
TL;DR: In this paper, a simple 2-port reciprocal ferrite switch that relies on the rotation of the dipolar mode in a ferrite post or disc for its operation is described, and an experimental switch was constructed in stripline at 2 GHz, with an insertion loss of 1 dB and an attenuation of 28 dB.
Abstract: The letter describes a simple 2-port reciprocal ferrite switch that relies on the rotation of the dipolar mode in a ferrite post or disc for its operation. The switch uses the fact that the electric field for this mode has a figure-of-eight pattern at the edge of the post or disc. In the unmagnetised state, this field pattern couples the inputn ad output ports of the transmission line. In the magnetised state, the two ports are decoupled, provided that the field is rotated through 90°, thereby placing a null of the figure-of-eight pattern at the input port. An experimental switch was constructed in stripline at 2 GHz, with an insertion loss of 1 dB and an attenuation of 28 dB.
TL;DR: In this paper, a relation is found which correlates insertion loss in stripline circulators with loss parameters x'' and tan /spl delta/δ, and also dielectric loss measurements have been carried out.
Abstract: Extensive microwave loss measurements have been performed at the frequency of 1.3 GHz on below resonance stripline Y circulators loaded with aluminum doped YIG. Extemal x'' have been measured on the same compositions. Also, dielectric loss measurements have been carried out. A relation is found which correlates insertion loss in stripline circulators with loss parameters x'' and tan /spl delta/.
01 Sep 1974