Expert MININEC Broadcast Professional

Expert MININEC Broadcast Professional is an advanced engineering tool for the design and analysis of wire antennas. Special options for analysis of commercial broadcast antennas have been added. Click here for a more general description of the Expert MININEC Series. Principal features of Expert MININEC Broadcast Professional are described in a general table and in the following.

File Handling

• open, save, and delete files
• geometry merge that can be used to merge the geometry of one file into an already existing file
• NEC file conversion can be used to convert a NEC-MoM file
• print setup

Geometry Constructs

• coordinate system selection including Cartesian, cylindrical and geographic coordinate systems
• geometry points defined in meters, centimeters, feet, inches or degrees
• environmental options including free space, perfect ground and real ground
• straight, helix, arc and circular wires
• point coordinate stepping that can be used to define increments for the geometry points
• Numerical Green's Function - It is possible to improve the computational time for a given problem using the Numerical Green's Function. For example, consider the analysis of a small antenna near a large structure. A computation is made for the complete problem. If the small antenna is the only part of the problem that is to be moved, the computational description of the large structure can be saved in a file and used in the subsequent calculations as the small antenna is moved.
• wire meshes
• symmetry. Symmetry is useful for the modeling of structures that are symmetrical about the z-axis. Symmetry is also efficient for the modeling of structures that have one nonsymmetrical cell on the z-axis. The remainder of the antenna structure must be described as symmetrical cells about the z-axis. An example of this type of antenna is a top-loaded monopole.
• transformations. Transformations move existing wires by rotation and translation. Copies of wires can be generated.

Planar antenna phased array

A transmit and receive planar phased array can be defined from a given antenna element defined in the Geometry definition and a source node defined in the Electrical definition. The amplitude and phased distributions for a transmit or the loads for a previously defined planar antenna phased array can be modified.

Electrical Constructs

• frequency stepping
• ground options
• loaded wires, lumped loads, passive circuits and transmission lines
• voltage/current and plane wave sources

Solution Space

• currents, charges
• impedance/admittance
• near fields and radiation pattern
• two-port coupling
• stub matching which can be used to define transmission lines for a single stub matching of a load to a lossless transmission line.
• broadcast array synthesis. Following a process used by the Federal Communications Commission (FCC), this option can be used to design a broadcast array. The FCC process uses a per unit pattern based upon the relative contribution (in the horizontal plane) to the radiation pattern of each radiating tower in the broadcast array. The relative contribution is described in terms of complex field ratios (e.g., magnitude and phase). The voltages at the bases of the towers in a broadcast array can be related to the field ratios and phases that result from the FCC AM directional antenna design procedure. The field ratios are the array parameters that are inputs to the FCC program RADIAT which is used to compute the electric field pattern and the constraints that determine the behavior of AM medium wave standard broadcast directional antennas in the United States.
• tower footing impedance. The "footing" impedance method is an approximation which uses a lumped load in series with the base of a tower on a perfect conducting ground plane to model the effects of a "lossy ground" with a given conductivity and dielectric constant.
• FCC ground wave. FCC ground wave calculates the ground wave electric field intensity at given frequencies and distance for given electric ground constants. This computation predicts the ground wave propagation used by the FCC in the AM broadcast band.

Diagnostics

• list of current nodes
• geometry guidelines
• definition evaluation and summary
• on-line and context sensitive help

Run Options

• current
• iterative sources
• near fields and radiation patterns
• automatic convergence test . This option is used to define a convergence test for the problem. The choice of the number of segments is critical to the validity of the computation. The accuracy is dependent on the of number of segments. However, an increase in the number of segments also increases the memory and computational time requirements. A convergence test can be used to determine a "reasonable" number of segments.
• frequency iteration and geometry points iteration

Display Types

• text and interfaces to most available spread sheets
• 3D geometry, 3D currents/charges, 3D patterns
• linear plots
• polar plots for patterns
• Smith chart

Display Options

• admittance/impedance
• effective height
• current moments
• current/charge
• coupling
• array synthesis
• load voltage
• near electric fields, near magnetic fields and radiation patterns
• radar cross section
• multiple curves plots

Problem Limits

• 10,000 unknowns and 4,000 wires