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txsite

Create RF transmitter site

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Description

Use a txsite object to create a radio frequency transmitter site.

A transmitter consists of an RF circuit and an antenna, where the RF circuit excites the antenna with a signal and power. Key characteristics of a transmitter include its output power, operating frequency, and antenna radiation pattern.

Creation

Syntax

tx = txsite
tx = txsite(coordsys)
tx = txsite(___,Name=Value)

Description

tx = txsite creates a radio frequency transmitter site in geographic coordinates.

example

tx = txsite(coordsys) sets the CoordinateSystem property. By default, transmitter sites use a geographic coordinate system. Create a transmitter site that uses a Cartesian coordinate system by specifying coordsys as "cartesian".

tx = txsite(___,Name=Value) sets properties using one or more name-value arguments.

  • For geographic transmitter sites, you can specify the location by setting the Latitude, Longitude, and AntennaHeight properties.

  • For Cartesian transmitter sites, you can specify the location by setting the AntennaPosition property.

example

Properties

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Site name, specified as a character vector, a string scalar, or a row or column vector of N elements, where N is the number of sites. Create multiple sites by specifying a row or column vector.

Example: tx.Name = "Fenway Park";

Example: tx.Name = ["Fenway Park","Faneuil Hall","Bunker Hill Monument"];

Data Types: char | string

Coordinate system used to the reference the location of the site, specified as 'geographic' or 'cartesian'.

  • 'geographic' — Geographic coordinate system. Specify the locations of the transmitter sites using the Latitude, Longitude, and AntennaHeight properties.

  • 'cartesian' — Cartesian coordinate system. Specify the locations of the transmitter sites using the AntennaPosition property.

Example: tx.CoordinateSystem = "cartesian"

Latitude coordinates of the site, in degrees, specified as a numeric scalar in the range [–90, 90], or as a row or column vector of N elements in the range [–90, 90]. Create multiple sites by specifying a row or column vector.

The coordinates are referenced using the World Geodetic System of 1984 (WGS 84) reference ellipsoid.

Example: tx.Latitude = 45.098

Example: tx.Latitude = [42.3467 42.3598 42.3763];

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Longitude coordinates of the site, in degrees, specified as a numeric scalar in the range [–180, 180], or as a row or column vector of N elements in the range [–180, 180]. Create multiple sites by specifying a row or column vector.

The coordinates are referenced using the WGS 84 reference ellipsoid.

Example: tx.Longitude = -71.0972

Example: tx.Longitude = [-71.0972 -71.0545 -71.0611];

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Antenna element or array, specified as one of these options:

  • 'isotropic', which models an antenna that radiates uniformly in all directions.

  • An antenna element from the Antenna Catalog or an array element from the Array Catalog. To specify an antenna element, design the antenna element at the required receive frequency by using the design function. Then, add the antenna element to the transmitter site. This option requires Antenna Toolbox™.

  • An arrayConfig (Communications Toolbox) object. This option requires Communications Toolbox™.

  • An antenna object in Antennas, Microphones, and Sonar Transducers (Phased Array System Toolbox) or an array object in Array Geometries and Analysis (Phased Array System Toolbox). This option requires Phased Array System Toolbox™.

Example: tx.Antenna = monopole

Antenna x-axis angle defined with reference to a local Cartesian coordinate system, in degrees, specified as a numeric scalar representing an azimuth angle or as a 2-by-1 vector or a 2-by-N matrix representing both azimuth and elevation angles.

For sites with geographic coordinates, the azimuth angle is measured counterclockwise from the east along the antenna x-axis. For sites with Cartesian coordinates, the azimuth angle is measured from the global x-axis around the global z-axis. Specify the azimuth angle in the range [–180, 180].

The elevation angle is measured from the antenna x-axis along the horizontal (or xy) plane. Specify the elevation angle in the range [–90, 90].

Example: tx.AntennaAngle = 25;

Example: tx.AntennaAngle = [25 -80];

Antenna height above the ground or building surface, in meters, specified as a nonnegative numeric scalar. This value must be less than or equal to 6,371,000 m.

If the site location coincides with the building location, the antenna height is measured from the top of the building to the center of the antenna. Otherwise,the height is measured from ground elevation to the center of the antenna.

Example: tx.AntennaHeight = 15;

Dependencies

To enable this property, the value of CoordinateSystem must be 'geographic'.

Data Types:

Position of the antenna center, in meters, specified as a 3-by-1 vector representing x-, y-, and z-axis Cartesian coordinates.

Example: tx.AntennaPosition = [0;2;4];

Dependencies

To enable this property, the value of CoordinateSystem must be 'cartesian'.

Data Types:

System loss in dB, specified as a nonnegative scalar.

System loss includes transmission line loss and any other miscellaneous system losses.

Example: tx.SystemLoss = 10;

Data Types:

Transmitter operating frequency, in Hz, specified as a positive scalar in the range [1e3 200e9].

Example: tx.TransmitterFrequency = 30e9;

Data Types: double

Signal power at transmitter output, in W, specified as a positive scalar. The transmitter out is connected to the antenna.

Example: tx.TransmitterPower = 30;

Data Types: double

Object Functions

showShow site in Site Viewer
hideHide site from Site Viewer
distanceDistance between sites
angleAngle between sites
elevationElevation of site
locationCoordinates at distance and angle from site
losDisplay or compute line-of-sight (LOS) visibility status
coverageDisplay or compute coverage map
sinrDisplay or compute signal-to-interference-plus-noise (SINR) ratio
patternDisplay antenna radiation pattern in Site Viewer

Examples

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Open Live Script

Create a transmitter site. By default, transmitter sites use geographic coordinates. Specify the latitude as 42.3001 degrees and the longitude as -71.3504 degrees.

tx = txsite(Name="MathWorks Apple Hill", ...
    Latitude=42.3001,Longitude=-71.3504);

Display the antenna radiation pattern for the site.

pattern(tx)

Transmitter site and antenna radiation pattern displayed over satellite imagery

Open Live Script

Create a dipole antenna that has a resonant frequency of 2.5e9 Hz. Create a transmitter site in geographic coordinates that uses the dipole antenna.

fq = 2.5e9;
ant = design(dipole,fq);

tx = txsite(Name="MathWorks Apple Hill", ...
    Latitude=42.3001,Longitude=-71.3504, ...
    Antenna=ant,TransmitterFrequency=fq);

Display the transmitter site. 

show(tx)

Transmitter site displayed over satellite imagery

Open Live Script

Specify the names, latitudes, and longitudes of three locations.

name = ["Fenway Park","Faneuil Hall","Bunker Hill Monument"];
lat = [42.3467 42.3598 42.3763];
lon = [-71.0972 -71.0545 -71.0611];

Specify the frequency of the transmitters in Hz.

fq = 2.5e9;

Create an array of transmitter sites in geographic coordinates that uses dipole antennas. 

txs = txsite(Name=name,Latitude=lat,Longitude=lon, ...
Antenna=dipole,TransmitterFrequency=fq);

Display the transmitter sites. 

show(txs)

Three transmitter sites displayed over satellite imagery

Version History

Introduced in R2017b

See Also

Objects