Showing papers on "Microstrip antenna published in 1973"

Microstrip Dispersion Model

Abstract: The assumption that the quasi-TEM mode on microstrip is primarily a single longitudinal-section electric (LSE) mode leads to a transmission line model whose dispersion behavior can be analyzed and related to that of microstrip. Appropriate approximations yield simple, closed-form expressions that allow slide-rule prediction of microstrip dispersion.

Microstrip antenna structures and arrays

Abstract: A microstrip antenna structure formed from a unitary conducting surface separated from a ground plane by a dielectric film where the r.f. radiator and feedlines form a generally planar arrangement of unitary integrally formed electrical conductors. The r.f. radiators are fed from an outside edge to selectively produce linearly and/or circularly polarized radiation at a selected resonant frequency(s). Necessary fixed phase shifting circuits are integrally formed by printed circuit techniques in the generally planar arrangement of electrical conductors for the circularly polarized radiators. A plurality of such antenna elements are also formed into a phased antenna array to achieve substantially ideal array gain thus producing an extremely high gain antenna with inexpensive printed circuit board construction techniques. Furthermore, appropriately controlled phase shifting networks may be integrally formed within the generally planar array of electrical conductors in combination with switchable diode elements to achieve any desired relative phase shifts between the array elements and thus to steer the array beam in a desired direction.

Electrically scanned microstrip antenna

Abstract: A microstrip antenna including a dielectric layer loaded with a ferrite material disposed between a ground plane and a generally planar or single layer arrangement of electrical conductors constituing both r.f. radiators and r.f. feedlines. Either or both of the r.f. radiators and feedlines include special d.c. circuits for passing d.c. electrical currents. When the d.c. electrical currents are passed through the r.f. radiators, the permeability of the ferrite loaded dielectric is altered thus scanning the resonant frequency of a radiator in accordance with the applied d.c. current or voltage. Furthermore, when the d.c. currents are passed through the r.f. feedline, or portions thereof, the magnetic fields set up in the ferrite loaded dielectric causes controlled phase shifts to occur in r.f. energy passing there along thus effecting controlled phase shifts and hence beam scanning of an array of such radiators as a function of the d.c. current or voltage.

Microstrip phased array antennas

Abstract: High velocity aircraft, missiles, and rockets require conformai, thin antennas. Ideally, an antenna "paper thin" would best suit the aerodynamic and mechanical engineer. This antenna would neither, disturb the aerodynamic flow, nor would it protrude inwardly to disrupt the mechanical structure.

Dispersion of Parallel-Coupled Microstrip (Short Papers)

Abstract: Dispersion predictions for the even and odd modes of parallel-coupled microstrip obtained by using the LSE-mode model for microstrip are found to be in good agreement with recently published measurements. Both the basic dispersion relationship and the empirical factor G appear to be the same as for single microstrip lines if the even- and odd-mode impedances used are those of the total parallel-coupled configuration rather than those of a single line of the coupled pair.

The Electrical Characterization of a Right-Angled Bend in Microstrip Line (Short Papers)

Abstract: An approach to the solution of the equivalent electrical length, and the additional capacitance, associated with a right-angled bend in microstrip line are outlined. The calculations were performed under static assumptions, corresponding to a quasi-TEM mode of propagation of the fields. Although little theoretical work existed for comparison at the time of writing, encouraging reinforcement was gained with experimental results cited from the literature.

Thin sandwich telemetry antenna

Abstract: A thin sandwich slot antenna is provided which produces a cardiod shaped antenna pattern. The antenna structure requires no antenna cavity or other remote structure behind the antenna. A thin-film antenna is supported by a thin dielectric strip and contoured to the shape of support structure. A metallic support structure becomes the ground plane for the antenna otherwise a metallic ground plane is placed behind the radiating element.

Equivalent Representation of an Abrupt Impedance Step in Microstrip Line (Short Papers)

Abstract: The equivalent electrical lengths of uniform microstrip line associated with an abrupt impedance step are first evaluated, under static assumptions. The importance of these results in establishing a reference plane for the step, and in the application of calculations of capacitance associated with the step, is then demonstrated. Furthermore, some interesting dualities are discerned from the results.

Computer design of antenna reflectors.

Abstract: Performance of paraboloidal antenna reflectors is adversely influenced by surface distortions from a perfect paraboloid, which cause pathlength variations of the RF energy beam. The structural design objective for the surface backup structure is to minimize the rms pathlength deviations for gravity loading. Two design approaches are illustrated and applied to sample antenna structure designs. These are a sectional search method and a virtual work/Lagrange multiplier method. Both are shown to provide useful performance improvements. The second, however, appears to be more suited for application to design of large antenna structures.

Loss Calculations of Coupled Microstrip Lines (Short Papers)

Abstract: Loss calculations have been performed to yield useful data relevant to the complementary odd and even modes propagating along a pair of identical coupled microstrip lines. The calculations are based on methods applied to the single-line case and indicate substantial differences in attenuation occurring between the odd and even modes for particular geometries.

Radiation symmetries of antenna arrays

Abstract: A new class of antenna array lattices is examined and classified by using the formalism of the space point groups. The space symmetries of the current excitations and their resulting patterns are investigated. A new procedure for designing orthogonal antenna field patterns is developed.

Recording of dynamic antenna radiation patterns

Abstract: A concept is presented for recording antenna radiation patterns as functions of two parameters simultaneously. An implementation of the technique results in a significant savings in the measurement time required to document antenna performance as a function of the particular pair of parameters of interest. Application of the concept to beam scanning and frequency scanning antennas is discussed.

Accurate boresight measurements of large antennas and radomes

Abstract: A laser-mirror system incorporated into an antenna pattern range is capable of aligning the antenna tower to measure the radome boresight error of large antennas to within 0.1 mrad angular accuracy. The simplicity of the alignment system makes it relatively easy to position the antenna, with or without its radome to a preestablished mechanical reference plane. Hence, deflection of the antenna tower system due to different loadings can be determined which otherwise would be undetected with most range facilities.